China Joins the Search for Extra-Terrestrial Life

China Joins the Search for Extra-Terrestrial Life

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For many years, space exploration seemed to be largely an American obsession. NASA was the only space agency on the planet with ambitious plans and the consistent financing to carry them out.

But after first challenging the United States’ global economic hegemony, the planet’s most populous country has now extended the competition to the space race . While NASA is still preeminent, China’s space program, under the supervision of the People’s Liberation Army, has emerged as the second-most active on Earth.

China is currently launching more rockets into space than any country. Just recently, it became the first nation to land a rover on the far side of the Moon, and it has plans to construct a space station within the next few years. Eventually China hopes to land astronauts on the Moon as well, and these plans might explain why President Trump suddenly announced his intention to revive the Apollo program and land American astronauts on the Moon again in five years .

In the midst of all this space-oriented activity, China has been expanding its space exploration efforts in yet another way. The country’s space scientists have developed an intense interest in deep-space surveillance via telescope, and they have initiated multiple projects designed to elevate their standing in astronomy.

China Has Big Plans for Antarctica

China’s initial foray into the super-telescope game occurred in Antarctica.

In 2012, they installed the largest optical telescope that had yet to be deployed there, called the AST3-1 . This powerful 4.5-metre optical device will scan the skies in search of supernovas and other bodies of light and matter outside the solar system.

China installed this telescope at a location known as Dome A, which is the highest point on the Antarctic continent. This spot is perfect for observing deep space with no atmospheric interference. China installed another less powerful telescope on Dome A in 2008, and the success of that project convinced them to ramp up their efforts in the southern polar region.

“China started late in Antarctic astronomic exploration,” admitted Yuan Xiangyan, the deputy head of China’s Antarctic expedition team, before adding that his country “has made great progress. Since we took advantage of the observation point at Dome A, more countries have expressed willingness to cooperate with us.”

The plan all along was for China to install three powerful optical telescopes in the Dome A region. But a shortage of government funding has put the second and third stages of the project on hold. Once they’re ready to go online, these new telescopes will have infrared as well as optical detection capability, which would allow Chinese astronomers to study dark matter, dark energy and ongoing star formation inside gas clouds.

China Wants Astronomical Supremacy and it Wants it FAST

Not content to limit their pursuit of astronomical knowledge to the optical and infrared bands, China has made major investments in the area of radio astronomy. In 2016, they completed the construction and installation of the Five-hundred metre Aperture Spherical Telescope (FAST) in southwestern China. As soon as it began functioning FAST immediately became the world’s biggest radio telescope, dwarfing in size the 300-metre telescope installed by the United States at Arecibo in Puerto Rico.

This impressively massive telescope will be used to track and catalog pulsars, search for elusive gravitational waves and dark matter, and look for planets circling stars throughout the Milky Way and other galaxies. Measuring fluctuations in radio wave activity makes all of these things possible. It also empowers the search for extraterrestrial life.

For a long time astronomers, have hypothesized that alien civilizations might advertise their presence by sending radio signals across space. All the SETI (search for extraterrestrial intelligence) projects have scanned the skies in search of unusual radio signals in patterned or repeating form, which could not be produced by natural processes.

Conceivably, powerful optical signals could be sent by such civilizations as well, and optical telescopes are also useful in the hunt for extraterrestrial life. But radio telescopes are still considered the best bet for finding evidence of faraway life, and the FAST telescope has pushed China to the forefront of this quest.

“FAST’s potential to discover an alien civilization will be five to ten times that of current equipment, as it can see farther and darker planets,” declared Peng Bo, the deputy director of the FAST project. The unmatched range of this new telescope raises the interesting possibility that alien radio signals might be detected even if they weren’t intentionally beamed across space, but were transmitted only as a byproduct of a civilization’s normal technological activity.

“We look not only for television signals, but also atomic bomb signals,” explained Li Di, the chief scientist at the FAST facility. “We’ll give full play to our imaginations when processing the signals. It’s a complete exploration, as we don’t know what an alien is like.”

Searching the Skies from the Tibetan Plateau

High-elevation areas offer the best observation conditions for telescopes. Consequently, China is moving fast to install multiple observatories on the high Tibetan plateau . Four large telescopes are planned, and the first one was completed in April of this year.

The Large High Altitude Air Shower Observatory (LHAASO) will study high-energy gamma rays, which are the most energetic photons traveling across the broad expanses of the universe. The origin of gamma rays is a mystery, and this new Chinese telescope will inspect neutron stars, supernovas and black holes to find evidence of gamma ray production and activity.

The other telescopes planned for extreme altitudes in Tibet will study a broad range of astronomical phenomena, including solar flares, coronal mass ejections, gravitational waves and the evolution of galaxies. The largest of these telescopes, called LOT (Large Optical Infrared Telescope), will be tasked to search for exoplanets (planets in other solar systems). This will represent a major step forward in Chinese astronomy, since the search for such planets —and especially for those that might support life—are currently a major preoccupation of planetary scientists across the globe.

Finding planets that might host living creatures is an indirect way of searching for life in the universe. China is clearly determined to become active participants in this exciting search.

Chinese Astronomy is Going into Orbit

In June 2019, China launched its first X-ray telescope (called Huiyan, which means ‘insight’ in Chinese) into orbit. This is the first space telescope of any type that China has deployed, and it will survey deep space in search of gamma rays, gravitational waves, neutron stars, pulsars, signs of supernovas, black holes and more. The Earth’s atmosphere absorbs X-ray signals, meaning that astronomers will only have access to detailed X-ray measurements if they are collected and transmitted from space.

“The only way to make original achievements is to construct our own observation instruments,” said Xiong Shaolin, from the Institute of High Energy Physics of the Chinese Academy of Sciences. “Now Chinese scientists have created this space telescope with its many unique advantages, and its quite possible we will discover new, strange and unexpected phenomena in the universe.”

China and the New Space Race

It is clear from the flurry of activity they’ve initiated that China is serious about attaining preeminence in astronomy, space science and space technology.

In each of its astronomical endeavors, China has spent liberally to develop and implement solutions using the most innovative and advanced technology. While their budget for space science does not match NASA’s, their reliance on sophisticated technology is allowing them to achieve maximum results from the funds they are investing.

Searching for signs of intelligent life elsewhere in the universe is not their only purpose. But their comprehensive and enthusiastic approach to interstellar exploration could make them the odds-on favourite to find conclusive proof of an alien civilization, assuming it will one day be found.

Of course, NASA will have something to say about this. But China is making it clear that we can no longer take United States dominance in space for granted. The new space race is on, and the nation declared the winner may be the one that acquires irrefutable evidence that life does indeed exist elsewhere in the universe.


Extraterrestrial life

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Extraterrestrial life, life that may exist or may have existed in the universe outside of Earth. The search for extraterrestrial life encompasses many fundamental scientific questions. What are the basic requirements for life? Could life have arisen elsewhere in the solar system? Are there other planets like Earth? How likely is the evolution of intelligent life?


China Joins the Search for Extra-Terrestrial Life - History

National Aeronautics and Space Administration
NASA History Program Office

Since the beginning of civilization, people have wondered if we are alone in the universe or whether there is intelligent life somewhere else. In the late twentieth century, scientists converged upon the basic idea of scanning the sky and "listening" for non-random patterns of electromagnetic emissions such as radio or television waves in order to detect another possible civilization somewhere else in the universe. In late 1959 and early 1960, the modern SETI era began when Frank Drake conducted the first such SETI search at approximately the same time that Giuseppe Cocconi and Philip Morrison published a key journal article suggesting this approach.

NASA joined in SETI efforts at a low-level in the late 1960s and early 1970s. Some of these SETI-related efforts included Project Orion, the Microwave Observing Project, the High Resolution Microwave Survey, and Toward Other Planetary Systems. On Columbus Day in 1992, NASA initiated a formal, more intensive, SETI program. Less than a year later, however, Congress canceled the program.

For more background on SETI history and the cancellation of NASA's SETI program, you may want to read an article from the Journal of the British Interplanetary Society. Part of the cancelled program was picked up by the private, non-profit SETI Institute, and a smaller part by the non-profit, grassroots SETI League. NASA is still very much interested in astrobiology and the question of whether or not we are alone has been adopted by the NASA Origins program. For a comprehensive look at current SETI issues, Sky & Telescope magazine's SETI Section contains regularly updated articles and resources.

We also have several related full-length books now on-line. Archaeolology, Anthropology, and Interstellar Communications, edited by Douglas A. Vakoch, (NASA SP-2013-4413) contains several relevant chapters. You may want to view the full text and images of The Search for Extraterrestrial Intelligence (NASA SP-419, 1977), which was edited by Philip Morrison, John Billingham, and John Wolfe. The Web version of Project Orion: A Design Study of a System for Detecting Extrasolar Planets (NASA SP-436, 1980) is now available on-line. A fourth SETI-related volume that is now on-line is Life in the Universe (NASA CP-2156, 1981). Special thanks to Chris Gamble for preparing these volumes for the Web.


Man claims ‘UFO hovered over his car and beamed a light at him’ after Pentagon report ‘didn’t rule out alien life’

A DRIVER has claimed a UFO hovered over his car and beamed a light at him during a strange encounter he pictured on Tuesday night.

Jose Carrodegua says he spotted the mysterious craft in Cape Coral, Florida, ahead of the release of a bombshell Pentagon report into alien life.

Carrodegua told local station WBBH-TV: "The light began to separate into two and then come back together.

"It was a black diamond with lights on the side and one red light towards the center, not all the way to the back of the craft.

"I was like holy s**t, that’s a UFO. That’s not nothing from here.

"We were just in awe. It was right overhead, floating over us basically. There was no sound. It was magnificent."

Carrodegua added: "Right now in my heart I believe it was definitely something from another planet."

Air Force pilot Kevin Russo told the network the lack of sound from the craft is the "biggest clue" it came from another planet.

He added: "We don’t have any silent running aircraft or helicopters that I know of in our world at this time.

"I would go on the 90 percent side. that it’s probably not from here."

Federal Aviation Administration (FAA) records show there were no aircraft in the area at the time.

Bill Clinton said earlier this month "there is something you could call life" in space when quizzed about recent UFOs sightings.

Clinton joins fellow former Democrat President Barack Obama in raising the alarm about extraterrestrial life following a spate of sightings by US military personnel.

Probed on whether UFOs were real, Clinton said the US government has never proved their existence but that "there are things flying around up there that we haven't fully identified yet."

"Keep in mind there are billions of galaxies in an ever-expanding universe," Clinton added.

"I mean, you can't even get your mind around the sheer number of things that are out there. No one knows, but I think the probability is that there is something you would call life somewhere else."

Weeks earlier, Obama told The Late Late Show with James Corden the US was monitoring UFO sightings.

"Well, when it comes to aliens, there are some things I just can't tell you on air," Obama said.

"What is true, and I'm actually being serious here, is that there is footage and records of objects in the skies that we don't know exactly what they are.

"We can't explain how they move, their trajectory. They did not have an easily explainable pattern."

The comments come as what was regarded as a conspiracy theory is now being taken seriously as a national security threat.

A bombshell Pentagon report - which is yet to be released to the public - is tipped to confirm the vast majority of the 120 sightings made by US Navy personnel over the past two decades were not American military or other government technology.

Those findings - due to be presented publicly to Congress later this month - eliminate the possibility that the Navy pilots may have seen some form of secret government aircraft, The New York Times reports.

Officials believe that some of the aerial phenomena could have come from a rival power such as Russia or China amid fears that Moscow may have been experimenting with hypersonic technology.

Senior officials briefed on the findings said that because the report is inconclusive, the government could not definitively rule out the alien spacecraft theories.

An unclassified version of the findings is set to be released to Congress by June 25. The final report, however, will still include one classified annex, according to the Times.

Officials said that the annex will not contain any evidence of alien activity, but the fact that it must remain classified will likely fuel increased speculation.

Former Pentagon official Lue Elizondo said the military has been seeing mysterious "tic-tac" UFOs since 1950, possibly even earlier.

Elizondo said senior military personnel and scientists have spotted UFOs over US military facilities on multiple occasions.

"The US government has finally admitted that this is not some sore of secret US technology," he said. "But now, there is some wiggle room to say, 'Well maybe it is some foreign adversarial technology.'"

Elizondo poured cold water on the theory Russia or China could be behind the aerial phenomenons.

He said Russia had shared a lot of its UFO information with the US following the fall of the Berlin Wall while China, Elizondo said, was behind the curve on technology in comparison to the US and unlikely to have developed any such aircraft.

"We’re talking about a country that somehow for 70 years has kept this technology that was at least 1,000 years ahead of us – kept it secret, was able to employ it against us all the way back to 1950," he said of the possibility.


Before We Find Aliens, Humans Need to Figure Ourselves Out

Are we alone? Humans have a lot of questions about alien life. But those beings, if they exist, likely have some questions of their own about humans, queries we may want to answer before we find any life beyond Earth.

That's because the answers we reach will shape how we respond to any such discovery in ways that have profound implications for us and that hypothetical life beyond Earth alike, according to Kathryn Denning, an anthropologist at York University in Canada who focuses on space exploration and extraterrestrial life. Some of those questions, the more anthropocentric ones, are already in the air, underlying conversations about the search for life.

But other questions would benefit from a shift in mindset that is uncommon in the field, Denning told Space.com. "We're still thinking [about a detection of extraterrestrial life] in terms of an intellectual problem about us and our place in the universe," she said. "[We] haven't thought through the consequences for that other life."

One key struggle may be the tendency to emphasize the question "Are we alone?" which Denning said speaks more to the recent history of science than to humanity in general. "A lot of people have already made that leap. They've already assumed that life is prevalent," she said.

It was only when science-minded people could get a very good look at neighbors like the moon and Mars that those assumptions began to change. "Thanks to astronomy, the universe kind of emptied out briefly in the mid-20th century," Denning said. "Up until that point, most people assumed it was full." And deciding for ourselves whether we are alone can't necessarily shape our response to a discovery beyond the degree of surprise with which we meet it.

Extending our interrogative and contemplative energy beyond that one question may turn out to be more helpful. Those questions could include how such a discovery will be announced. This has been discussed, but those conversations haven't kept up with the pace of change in society, Denning said. Chances are low that the sort of controlled, authority-laden announcement planned during previous decades would be pragmatic today.

"Any kind of scientific discovery now takes place in real time, in public view, and that involves all kinds of disagreements," Denning said. "You end up with different camps, and they're kind of fighting it out over Twitter or whatever. What is a nonspecialist audience supposed to think?"

Once we do have a new version of that conversation, it shouldn't stagnate again, since future decades will need to consider different circumstances once again, she added.

Denning said she also wants people to be more aware of how different communities may respond to the same new information and why. Because of different lived experiences, vulnerabilities and ways of seeing the world, a discovery that is exciting for some people may upset others. That variety of perspectives could be even more instructive in conversations about how humanity responds to the discovery of aliens: Approaches that some people see as maximizing humanity's opportunities could feel risky or threatening to other people, Denning said.

Figuring out how to respond to a discovery of life in a way that truly reflects all of humanity means finding a way to pull all those threads together into the same discussion. "We have to have, I think, better conversations about how do we talk about a discovery," Denning said. In particular, she said, those conversations need to include a much broader swath of humanity than they currently do.

And those discussions also need to recognize that societal confidence and credence are changing over time as well. Announcements or advice that may once have gone unquestioned because they came from an authority that no longer has such preeminence, Denning said. "All of this takes place against a backdrop where there is a crisis of scientific authority, particularly in America," she said. "There are just big problems with trust in expertise overall."

The conversations we have right now about potentially finding life lack another component that Denning said is vitally important: how we treat that life. "What we do with life on Earth? A lot of it is really awful," she said, pointing to millennia of consumption and captivity and disruption. "We control and contain and rework it culturally in absolutely every way that we can."

While the topic of planetary protection includes conversations about how to protect life both on Earth and beyond it, those discussions tend to view any extraterrestrial life as a scientific opportunity not as an ethical obligation, Denning said. That isn't good enough for her, she said, especially given what she called "the expansion of post-planetary capitalism."

There's reason to worry about the exploitation of alien life, given the precedent we have on Earth for what extraterrestrial life could look like: tiny so-called extremophilic organisms that can live in bitter cold, extreme heat, high saltiness and other difficult conditions. Those organisms, their genetic material and the compounds they can produce are highly sought after by companies looking to commercialize medicines and other valuable compounds. Denning said the same factors would affect any extraterrestrial extremophile life as well.

"When you see considerable private interest now in looking for life in the solar system, is that purely a scientific intellectual question with no hope of actual return?" Denning said. "Or is there something that either is at work now or would inevitably be at work at some point in terms of recruiting that life into some form of financial gain?"

Denning's concerns about these issues are strongly rooted in her background as an anthropologist, she said. She pointed to the likelihood of primates, "the creatures that are most like us," being made extinct in the wild within decades because of human activities.

"Those are the realities that anthropologists live with every day. That this is the truth of who we are and what we do," Denning said. "It's not all that we are, and it's not all that we could do, but left to our own devices, when we don't engage our higher reasoning and engage in protective actions, then some people have to protect life-forms from other people."


Contents

Search for extraterrestrial intelligence Edit

To detect extraterrestrial civilizations with radio telescopes, one must identify an artificial, coherent signal against a background of various natural phenomena that also produce radio waves. Telescopes capable of this include the Arecibo Observatory in Puerto Rico, the Allen Telescope Array [5] in Hat Creek, California and the new Five hundred meter Aperture Spherical Telescope in China. Various programs to detect extraterrestrial intelligence have had government funding in the past. Project Cyclops was commissioned by NASA in the 1970s to investigate the most effective way to search for signals from intelligent extraterrestrial sources, [4] but the report's recommendations were set aside in favor of the much more modest approach of Messaging to Extra-Terrestrial Intelligence (METI), the sending of messages that intelligent extraterrestrial beings might intercept. NASA then drastically reduced funding for SETI programs, which have since turned to private donations to continue their search. [6]

With the discovery in the late 20th and early 21st centuries of numerous extrasolar planets, some of which may be habitable, governments have once more become interested in funding new programs. In 2006 the European Space Agency launched COROT, the first spacecraft dedicated to the search for exoplanets, [7] and in 2009 NASA launched the Kepler space observatory for the same purpose. [8] By February 2013 Kepler had detected 105 [9] of the 4,758 confirmed exoplanets, [10] and one of them, Kepler-22b, is potentially habitable. [11] After it was discovered, the SETI Institute resumed the search for an intelligent extraterrestrial civilization, focusing on Kepler ' s candidate planets, [12] with funding from the United States Air Force. [13]

Newly discovered planets, particularly ones that are potentially habitable, have enabled SETI and METI programs to refocus projects for communication with extraterrestrial intelligence. In 2009 A Message From Earth (AMFE) was sent toward the Gliese 581 planetary system, which contains two potentially habitable planets, the confirmed Gliese 581d and the more habitable but unconfirmed Gliese 581g. [14] In the SETILive project, which began in 2012, human volunteers analyze data from the Allen Telescope Array to search for possible alien signals that computers might miss because of terrestrial radio interference. [15] The data for the study is obtained by observing Kepler target stars with the radio telescope. [12]

In addition to radio-based methods, some projects, such as SEVENDIP (Search for Extraterrestrial Visible Emissions from Nearby Developed Intelligent Populations) at the University of California, Berkeley, are using other regions of the electromagnetic spectrum to search for extraterrestrial signals. [16] Various other projects are not searching for coherent signals, but want to rather use electromagnetic radiation to find other evidence of extraterrestrial intelligence, such as megascale astroengineering projects. [17]

Several signals, such as the Wow! signal, have been detected in the history of the search for extraterrestrial intelligence, but none have yet been confirmed as being of intelligent origin. [18]

Impact assessment Edit

The implications of extraterrestrial contact depend on the method of discovery, the nature of the extraterrestrial beings, and their location relative to the Earth. [19] Considering these factors, the Rio Scale has been devised in order to provide a more quantitative picture of the results of extraterrestrial contact. [19] More specifically, the scale gauges whether communication was conducted through radio, the information content of any messages, and whether discovery arose from a deliberately beamed message (and if so, whether the detection was the result of a specialized SETI effort or through general astronomical observations) or by the detection of occurrences such as radiation leakage from astroengineering installations. [20] The question of whether or not a purported extraterrestrial signal has been confirmed as authentic, and with what degree of confidence, will also influence the impact of the contact. [20] The Rio Scale was modified in 2011 to include a consideration of whether contact was achieved through an interstellar message or through a physical extraterrestrial artifact, with a suggestion that the definition of artifact be expanded to include "technosignatures", including all indications of intelligent extraterrestrial life other than the interstellar radio messages sought by traditional SETI programs. [21]

A study by astronomer Steven J. Dick at the United States Naval Observatory considered the cultural impact of extraterrestrial contact by analyzing events of similar significance in the history of science. [22] The study argues that the impact would be most strongly influenced by the information content of the message received, if any. [22] It distinguishes short-term and long-term impact. [22] Seeing radio-based contact as a more plausible scenario than a visit from extraterrestrial spacecraft, the study rejects the commonly stated analogy of European colonization of the Americas as an accurate model for information-only contact, preferring events of profound scientific significance, such as the Copernican and Darwinian revolutions, as more predictive of how humanity might be impacted by extraterrestrial contact. [22]

The physical distance between the two civilizations has also been used to assess the cultural impact of extraterrestrial contact. Historical examples show that the greater the distance, the less the contacted civilization perceives a threat to itself and its culture. [23] Therefore, contact occurring within the Solar System, and especially in the immediate vicinity of Earth, is likely to be the most disruptive and negative for humanity. [23] On a smaller scale, people close to the epicenter of contact would experience a greater effect than would those living farther away, and a contact having multiple epicenters would cause a greater shock than one with a single epicenter. [23] Space scientists Martin Dominik and John Zarnecki state that in the absence of any data on the nature of extraterrestrial intelligence, one must predict the cultural impact of extraterrestrial contact on the basis of generalizations encompassing all life and of analogies with history. [24]

The beliefs of the general public about the effect of extraterrestrial contact have also been studied. A poll of United States and Chinese university students in 2000 provides factor analysis of responses to questions about, inter alia, the participants' belief that extraterrestrial life exists in the Universe, that such life may be intelligent, and that humans will eventually make contact with it. [25] The study shows significant weighted correlations between participants' belief that extraterrestrial contact may either conflict with or enrich their personal religious beliefs and how conservative such religious beliefs are. The more conservative the respondents, the more harmful they considered extraterrestrial contact to be. Other significant correlation patterns indicate that students took the view that the search for extraterrestrial intelligence may be futile or even harmful. [25]

Psychologists Douglas Vakoch and Yuh-shiow Lee conducted a survey to assess people's reactions to receiving a message from extraterrestrials, including their judgments about likelihood that extraterrestrials would be malevolent. [26] "People who view the world as a hostile place are more likely to think extraterrestrials will be hostile," Vakoch told USA Today. [27]

Post-detection protocols Edit

Various protocols have been drawn up detailing a course of action for scientists and governments after extraterrestrial contact. Post-detection protocols must address three issues: what to do in the first weeks after receiving a message from an extraterrestrial source whether or not to send a reply and analyzing the long-term consequences of the message received. [28] No post-detection protocol, however, is binding under national or international law, [24] and Dominik and Zarnecki consider the protocols likely to be ignored if contact occurs. [24]

One of the first post-detection protocols, the "Declaration of Principles for Activities Following the Detection of Extraterrestrial Intelligence", was created by the SETI Permanent Committee of the International Academy of Astronautics (IAA). [28] It was later approved by the Board of Trustees of the IAA and by the International Institute of Space Law, [28] and still later by the International Astronomical Union (IAU), the Committee on Space Research, the International Union of Radio Science, and others. [28] It was subsequently endorsed by most researchers involved in the search for extraterrestrial intelligence, [29] including the SETI Institute. [30]

The Declaration of Principles contains the following broad provisions: [31]

  1. Any person or organization detecting a signal should try to verify that it is likely to be of intelligent origin before announcing it.
  2. The discoverer of a signal should, for the purposes of independent verification, communicate with other signatories of the Declaration before making a public announcement, and should also inform their national authorities.
  3. Once a given astronomical observation has been determined to be a credible extraterrestrial signal, the astronomical community should be informed through the Central Bureau for Astronomical Telegrams of the IAU. The Secretary-General of the United Nations and various other global scientific unions should also be informed.
  4. Following confirmation of an observation's extraterrestrial origin, news of the discovery should be made public. The discoverer has the right to make the first public announcement.
  5. All data confirming the discovery should be published to the international scientific community and stored in an accessible form as permanently as possible.
  6. Should evidence for extraterrestrial intelligence take the form of electromagnetic signals, the Secretary-General of the International Telecommunications Union (ITU) should be contacted, and may request in the next ITU Weekly Circular to minimize terrestrial use of the electromagnetic frequency bands in which the signal was detected.
  7. Neither the discoverer nor anyone else should respond to an observed extraterrestrial intelligence doing so requires international agreement under separate procedures.
  8. The SETI Permanent Committee of the IAA and Commission 51 of the IAU should continually review procedures regarding detection of extraterrestrial intelligence and management of data related to such discoveries. A committee comprising members from various international scientific unions, and other bodies designated by the committee, should regulate continued SETI research.

A separate "Proposed Agreement on the Sending of Communications to Extraterrestrial Intelligence" was subsequently created. [32] It proposes an international commission, membership of which would be open to all interested nations, to be constituted on detection of extraterrestrial intelligence. [32] This commission would decide whether to send a message to the extraterrestrial intelligence, and if so, would determine the contents of the message on the basis of principles such as justice, respect for cultural diversity, honesty, and respect for property and territory. [32] The draft proposes to forbid the sending of any message by an individual nation or organization without the permission of the commission, and suggests that, if the detected intelligence poses a danger to human civilization, the United Nations Security Council should authorize any message to extraterrestrial intelligence. [32] However, this proposal, like all others, has not been incorporated into national or international law. [32]

Paul Davies, a member of the SETI Post-Detection Taskgroup, has stated that post-detection protocols, calling for international consultation before taking any major steps regarding the detection, are unlikely to be followed by astronomers, who would put the advancement of their careers over the word of a protocol that is not part of national or international law. [33]

Scientific literature and science fiction have put forward various models of the ways in which extraterrestrial and human civilizations might interact. Their predictions range widely, from sophisticated civilizations that could advance human civilization in many areas to imperial powers that might draw upon the forces necessary to subjugate humanity. [1] Some theories suggest that an extraterrestrial civilization could be advanced enough to dispense with biology, living instead inside of advanced computers. [1]

The implications of discovery depend very much on the level of aggressiveness of the civilization interacting with humanity, [34] its ethics, [35] and how much human and extraterrestrial biologies have in common. [36] These factors will govern the quantity and type of dialogue that can take place. [36] The question of whether contact is physical or through electromagnetic signals will also govern the magnitude of the long-term implications of contact. [37] In the case of communication using electromagnetic signals, the long silence between the reception of one message and another would mean that the content of any message would particularly affect the consequences of contact, [38] as would the extent of mutual comprehension. [39]

Friendly civilizations Edit

Many writers have speculated on the ways in which a friendly civilization might interact with humankind. Albert Harrison, a professor emeritus of psychology at the University of California, Davis, [40] thought that a highly advanced civilization might teach humanity such things as a physical theory of everything, how to use zero-point energy, or how to travel faster than light. [41] They suggest that collaboration with such a civilization could initially be in the arts and humanities before moving to the hard sciences, and even that artists may spearhead collaboration. [42] Seth D. Baum, of the Global Catastrophic Risk Institute, and others consider that the greater longevity of cooperative civilizations in comparison to uncooperative and aggressive ones might render extraterrestrial civilizations in general more likely to aid humanity. [43] In contrast to these views, however, Paolo Musso, a member of the SETI Permanent Study Group of the International Academy of Astronautics (IAA) and the Pontifical Academy of Sciences, took the view that extraterrestrial civilizations possess, like humans, a morality driven not entirely by altruism but for individual benefit as well, thus leaving open the possibility that at least some extraterrestrial civilizations are hostile. [44]

Futurist Allen Tough suggests that an extremely advanced extraterrestrial civilization, recalling its own past of war and plunder and knowing that it possesses superweapons that could destroy it, would be likely to try to help humans rather than to destroy them. [45] He identifies three approaches that a friendly civilization might take to help humanity: [45]

  • Intervention only to avert catastrophe: this would involve occasional limited intervention to stop events that could destroy human civilization completely, such as nuclear war or asteroid impact. [45]
  • Advice and action with consent: under this approach, the extraterrestrials would be more closely involved in terrestrial affairs, advising world leaders and acting with their consent to protect against danger. [45]
  • Forcible corrective action: the extraterrestrials could require humanity to reduce major risks against its will, intending to help humans advance to the next stage of civilization. [45]

Tough considers advising and acting only with consent to be a more likely choice than the forceful option. While coercive aid may be possible, and advanced extraterrestrials would recognize their own practices as superior to those of humanity, it may be unlikely that this method would be used in cultural cooperation. [45] Lemarchand suggests that instruction of a civilization in its "technological adolescence", such as humanity, would probably focus on morality and ethics rather than on science and technology, to ensure that the civilization did not destroy itself with technology it was not yet ready to use. [46]

According to Tough, it is unlikely that the avoidance of immediate dangers and prevention of future catastrophes would be conducted through radio, as these tasks would demand constant surveillance and quick action. [45] However, cultural cooperation might take place through radio or a space probe in the Solar System, as radio waves could be used to communicate information about advanced technologies and cultures to humanity. [45]

Even if an ancient and advanced extraterrestrial civilization wished to help humanity, humans could suffer from a loss of identity and confidence due to the technological and cultural prowess of the extraterrestrial civilization. [47] However, a friendly civilization may calibrate its contact with humanity in such a way as to minimize unintended consequences. [34] Michael A. G. Michaud suggests that a friendly and advanced extraterrestrial civilization may even avoid all contact with an emerging intelligent species like humanity, to ensure that the less advanced civilization can develop naturally at its own pace [48] this is known as the zoo hypothesis.

Hostile civilizations Edit

Science fiction films often depict humans successfully repelling alien invasions, but scientists more often take the view that an extraterrestrial civilization with sufficient power to reach the Earth would be able to destroy human civilization with minimal effort. [49] [4] [50] Operations that are enormous on a human scale, such as destroying all major population centers on a planet, bombarding a planet with deadly neutron radiation, or even traveling to another planetary system in order to lay waste to it, may be important tools for a hostile and totalitarian civilization. [51]

Deardorff speculates that a small proportion of the intelligent life forms in the galaxy may be aggressive, but the actual aggressiveness or benevolence of the civilizations would cover a wide spectrum, with some civilizations "policing" others. [34] According to Harrison and Dick, hostile extraterrestrial life may indeed be rare in the Universe, just as belligerent and autocratic nations on Earth have been the ones that lasted for the shortest periods of time, and humanity is seeing a shift away from these characteristics in its own sociopolitical systems. [41] In addition, the causes of war may be diminished greatly for a civilization with access to the galaxy, as there are prodigious quantities of natural resources in space accessible without resort to violence. [4] [52]

SETI researcher Carl Sagan believed that a civilization with the technological prowess needed to reach the stars and come to Earth must have transcended war to be able to avoid self-destruction. Representatives of such a civilization would treat humanity with dignity and respect, and humanity, with its relatively backward technology, would have no choice but to reciprocate. [53] Seth Shostak, an astronomer at the SETI Institute, disagrees, stating that the finite quantity of resources in the galaxy would cultivate aggression in any intelligent species, and that an explorer civilization that would want to contact humanity would be aggressive. [54] Similarly, Ragbir Bhathal claims that since the laws of evolution would be the same on another habitable planet as they are on Earth, an extremely advanced extraterrestrial civilization may have the motivation to colonize humanity in a similar manner to the European colonization of Australia. [55]

Disputing these analyses, David Brin states that while an extraterrestrial civilization may have an imperative to act for no benefit to itself, it would be naïve to suggest that such a trait would be prevalent throughout the galaxy. [56] Brin points to the fact that in many moral systems on Earth, such as the Aztec or Carthaginian one, non-military killing has been accepted and even "exalted" by society, and further mentions that such acts are not confined to humans but can be found throughout the animal kingdom. [56]

Baum et al. speculate that highly advanced civilizations are unlikely to come to Earth to enslave humans, as the achievement of their level of advancement would have required them to solve the problems of labor and resources by other means, such as creating a sustainable environment and using mechanized labor. [43] Moreover, humans may be an unsuitable food source for extraterrestrials because of marked differences in biochemistry. [4] For example, the chirality of molecules used by terrestrial biota may differ from those used by extraterrestrial beings. [43] Douglas Vakoch argues that transmitting intentional signals does not increase the risk of an alien invasion, contrary to concerns raised by British cosmologist Stephen Hawking, [57] [58] because "any civilization that has the ability to travel between the stars can already pick up our accidental radio and TV leakage". [59] [60]

Politicians have also commented on the likely human reaction to contact with hostile species. In his 1987 speech to the United Nations General Assembly, Ronald Reagan said, "I occasionally think how quickly our differences worldwide would vanish if we were facing an alien threat from outside this world." [61]

Equally advanced and more advanced civilizations Edit

Robert Freitas speculated in 1978 that the technological advancement and energy usage of a civilization, measured either relative to another civilization or in absolute terms by its rating on the Kardashev scale, may play an important role in the result of extraterrestrial contact. [62] Given the infeasibility of interstellar space flight for civilizations at a technological level similar to that of humanity, interactions between such civilizations would have to take place by radio. Because of the long transit times of radio waves between stars, such interactions would not lead to the establishment of diplomatic relations, nor any significant future interaction at all, between the two civilizations. [62]

According to Freitas, direct contact with civilizations significantly more advanced than humanity would have to take place within the Solar System, as only the more advanced society would have the resources and technology to cross interstellar space. [63] Consequently, such contact could only be with civilizations rated as Type II or higher on the Kardashev scale, as Type I civilizations would be incapable of regular interstellar travel. [63] Freitas expected that such interactions would be carefully planned by the more advanced civilization to avoid mass societal shock for humanity. [63]

However much planning an extraterrestrial civilization may do before contacting humanity, the humans may experience great shock and terror on their arrival, especially as they would lack any understanding of the contacting civilization. Ben Finney compares the situation to that of the tribespeople of New Guinea, an island that was settled fifty thousand years ago during the last glacial period but saw little contact with the outside world until the arrival of European colonial powers in the late 19th and early 20th centuries. The huge difference between the indigenous stone-age society and the Europeans' technical civilization caused unexpected behaviors among the native populations known as cargo cults: to coax the gods into bringing them the technology that the Europeans possessed, the natives created wooden "radio stations" and "airstrips" as a form of sympathetic magic. Finney argues that humanity may misunderstand the true meaning of an extraterrestrial transmission to Earth, much as the people of New Guinea could not understand the source of modern goods and technologies. He concludes that the results of extraterrestrial contact will become known over the long term with rigorous study, rather than as fast, sharp events briefly making newspaper headlines. [39]

Billingham has suggested that a civilization which is far more technologically advanced than humanity is also likely to be culturally and ethically advanced, and would therefore be unlikely to conduct astroengineering projects that would harm human civilization. Such projects could include Dyson spheres, which completely enclose stars and capture all energy coming from them. Even if well within the capability of an advanced civilization and providing an enormous amount of energy, such a project would not be undertaken. [64] For similar reasons, such civilizations would not readily give humanity the knowledge required to build such devices. [64] Nevertheless, the existence of such capabilities would at least show that civilizations have survived "technological adolescence". [64] Despite the caution that such an advanced civilization would exercise in dealing with the less mature human civilization, Sagan imagined that an advanced civilization might send those on Earth an Encyclopædia Galactica describing the sciences and cultures of many extraterrestrial societies. [65]

Whether an advanced extraterrestrial civilization would send humanity a decipherable message is a matter of debate in itself. Sagan argued that a highly advanced extraterrestrial civilization would bear in mind that they were communicating with a relatively primitive one and therefore would try to ensure that the receiving civilization would be able to understand the message. [66] Marvin Minsky believed that aliens might think similarly to humans because of shared constraints, permitting communication. [67] Arguing against this view, astronomer Guillermo Lemarchand stated that an advanced civilization would probably encrypt a message with high information content, such as an Encyclopædia Galactica, in order to ensure that only other ethically advanced civilizations would be able to understand it. [66] Douglas Vakoch assumes it may take some time to decode any message, telling ABC News that "I don't think we're going to understand immediately what they have to say." [68] "There’s going to be a lot of guesswork in trying to interpret another civilization," he told Science Friday, adding that "in some ways, any message we get from an extraterrestrial will be like a cosmic Rorschach ink blot test." [69]

Interstellar groups of civilizations Edit

Given the age of the galaxy, Harrison surmises that there exist several "galactic clubs", groupings of civilizations from across the galaxy. [52] Such clubs could begin as loose confederations or alliances, eventually developing into powerful unions of many civilizations. [52] If humanity could enter into a dialogue with one extraterrestrial civilization, it might be able to join such a galactic club. As more extraterrestrial civilizations, or unions thereof, are found, these could also become assimilated into such a club. [52] Sebastian von Hoerner has suggested that entry into a galactic club may be a way for humanity to handle the culture shock arising from contact with an advanced extraterrestrial civilization. [70]

Whether a broad spectrum of civilizations from many places in the galaxy would even be able to cooperate is disputed by Michaud, who states that civilizations with huge differences in the technologies and resources at their command "may not consider themselves even remotely equal". [71] It is unlikely that humanity would meet the basic requirements for membership at its current low level of technological advancement. [43] A galactic club may, William Hamilton speculates, set extremely high entrance requirements that are unlikely to be met by less advanced civilizations. [71]

When two Canadian astronomers argued that they potentially discovered 234 extraterrestrial civilizations [72] through analysis of the Sloan Digital Sky Survey database, Douglas Vakoch doubted their explanation for their findings, noting that it would be unusual for all of these stars to pulse at exactly the same frequency unless they were part of a coordinated network: "If you take a step back," he said, "that would mean you have 234 independent stars that all decided to transmit the exact same way." [73]

Michaud suggests that an interstellar grouping of civilizations might take the form of an empire, which need not necessarily be a force for evil, but may provide for peace and security throughout its jurisdiction. [74] Owing to the distances between the stars, such an empire would not necessarily maintain control solely by military force, but may rather tolerate local cultures and institutions to the extent that these would not pose a threat to the central imperial authority. [74] Such tolerance may, as has happened historically on Earth, extend to allowing nominal self-rule of specific regions by existing institutions, while maintaining that area as a puppet or client state to accomplish the aims of the imperial power. [74] However, particularly advanced powers may use methods, including faster-than-light travel, to make centralized administration more effective. [74]

In contrast to the belief that an extraterrestrial civilization would want to establish an empire, Ćirković proposes that an extraterrestrial civilization would maintain equilibrium rather than expand outward. [75] In such an equilibrium, a civilization would only colonize a small number of stars, aiming to maximize efficiency rather than to expand massive and unsustainable imperial structures. [75] This contrasts with the classic Kardashev Type III civilization, which has access to the energy output of an entire galaxy and is not subject to any limits on its future expansion. [75] According to this view, advanced civilizations may not resemble the classic examples in science fiction, but might more closely reflect the small, independent Greek city-states, with an emphasis on cultural rather than territorial growth. [75]

Extraterrestrial artifacts Edit

An extraterrestrial civilization may choose to communicate with humanity by means of artifacts or probes rather than by radio, for various reasons. While probes may take a long time to reach the Solar System, once there they would be able to hold a sustained dialogue that would be impossible using radio from hundreds or thousands of light-years away. [76] Radio would be completely unsuitable for surveillance and continued monitoring of a civilization, and should an extraterrestrial civilization wish to perform these activities on humanity, artifacts may be the only option other than to send large, crewed spacecraft to the Solar System. [76]

Although faster-than-light travel has been seriously considered by physicists such as Miguel Alcubierre, [77] Tough speculates that the enormous amount of energy required to achieve such speeds under currently proposed mechanisms means that robotic probes traveling at conventional speeds will still have an advantage for various applications. [76] 2013 research at NASA's Johnson Space Center, however, shows that faster-than-light travel with the Alcubierre drive requires dramatically less energy than previously thought, [78] needing only about 1 tonne of exotic mass-energy [79] to move a spacecraft at 10 times the speed of light, in contrast to previous estimates that stated that only a Jupiter-mass object would contain sufficient energy to power a faster-than-light spacecraft. [note 1]

According to Tough, an extraterrestrial civilization might want to send various types of information to humanity by means of artifacts, such as an Encyclopædia Galactica, containing the wisdom of countless extraterrestrial cultures, or perhaps an invitation to engage in diplomacy with them. [76] A civilization that sees itself on the brink of decline might use the abilities it still possesses to send probes throughout the galaxy, with its cultures, values, religions, sciences, technologies, and laws, so that these may not die along with the civilization itself. [76]

Freitas finds numerous reasons why interstellar probes may be a preferred method of communication among extraterrestrial civilizations wishing to make contact with Earth. A civilization aiming to learn more about the distribution of life within the galaxy might, he speculates, send probes to a large number of star systems, rather than using radio, as one cannot ensure a response by radio but can (he says) ensure that probes will return to their sender with data on the star systems they survey. [80] Furthermore, probes would enable the surveying of non-intelligent populations, or those not yet capable of space navigation (like humans before the 20th century), as well as intelligent populations that might not wish to provide information about themselves and their planets to extraterrestrial civilizations. [80] In addition, the greater energy required to send living beings rather than a robotic probe would, according to Michaud, be only used for purposes such as a one-way migration. [81]

Freitas points out that probes, unlike the interstellar radio waves commonly targeted by SETI searches, could store information for long, perhaps geological, timescales, [80] and could emit strong radio signals unambiguously recognizable as being of intelligent origin, rather than being dismissed as a UFO or a natural phenomenon. [80] Probes could also modify any signal they send to suit the system they were in, which would be impossible for a radio transmission originating from outside the target star system. [80] Moreover, the use of small robotic probes with widely distributed beacons in individual systems, rather than a small number of powerful, centralized beacons, would provide a security advantage to the civilization using them. [80] Rather than revealing the location of a radio beacon powerful enough to signal the whole galaxy and risk such a powerful device being compromised, decentralized beacons installed on robotic probes need not reveal any information that an extraterrestrial civilization prefers others not to have. [80]

Given the age of the Milky Way galaxy, an ancient extraterrestrial civilization may have existed and sent probes to the Solar System millions or even billions of years before the evolution of Homo sapiens. [81] Thus, a probe sent may have been nonfunctional for millions of years before humans learn of its existence. [81] Such a "dead" probe would not pose an imminent threat to humanity, but would prove that interstellar flight is possible. [81] However, if an active probe were to be discovered, humans would react much more strongly than they would to the discovery of a probe that has long since ceased to function. [81]

Theological Edit

The confirmation of extraterrestrial intelligence could have a profound impact on religious doctrines, potentially causing theologians to reinterpret scriptures to accommodate the new discoveries. [82] However, a survey of people with many different religious beliefs indicated that their faith would not be affected by the discovery of extraterrestrial intelligence, [82] and another study, conducted by Ted Peters of the Pacific Lutheran Theological Seminary, shows that most people would not consider their religious beliefs superseded by it. [83] Surveys of religious leaders indicate that only a small percentage are concerned that the existence of extraterrestrial intelligence might fundamentally contradict the views of the adherents of their religion. [84] Gabriel Funes, the chief astronomer of the Vatican Observatory and a papal adviser on science, has stated that the Catholic Church would be likely to welcome extraterrestrial visitors warmly. [85]

Contact with extraterrestrial intelligence would not be completely inconsequential for religion. The Peters study showed that most non-religious people, and a significant minority of religious people, believe that the world could face a religious crisis, even if their own beliefs were unaffected. [83] Contact with extraterrestrial intelligence would be most likely to cause a problem for western religions, in particular traditionalist Christianity, because of the geocentric nature of western faiths. [86] The discovery of extraterrestrial life would not contradict basic conceptions of God, however, and seeing that science has challenged established dogma in the past, for example with the theory of evolution, it is likely that existing religions will adapt similarly to the new circumstances. [87] Douglas Vakoch argues that it is not likely that the discovery of extraterrestrial life will impact religious beliefs. [88] In the view of Musso, a global religious crisis would be unlikely even for Abrahamic faiths, as the studies of himself and others on Christianity, the most "anthropocentric" religion, see no conflict between that religion and the existence of extraterrestrial intelligence. [44] In addition, the cultural and religious values of extraterrestrial species would likely be shared over centuries if contact is to occur by radio, meaning that rather than causing a huge shock to humanity, such information would be viewed much as archaeologists and historians view ancient artifacts and texts. [44]

Funes speculates that a decipherable message from extraterrestrial intelligence could initiate an interstellar exchange of knowledge in various disciplines, including whatever religions an extraterrestrial civilization may host. [89] Billingham further suggests that an extremely advanced and friendly extraterrestrial civilization might put an end to present-day religious conflicts and lead to greater religious toleration worldwide. [90] On the other hand, Jill Tarter puts forward the view that contact with extraterrestrial intelligence might eliminate religion as we know it and introduce humanity to an all-encompassing faith. [2] Vakoch doubts that humans would be inclined to adopt extraterrestrial religions, [91] telling ABC News "I think religion meets very human needs, and unless extraterrestrials can provide a replacement for it, I don't think religion is going to go away," and adding, "if there are incredibly advanced civilizations with a belief in God, I don't think Richard Dawkins will start believing." [92]

Political Edit

Tim Folger speculates that news of radio contact with an extraterrestrial civilization would prove impossible to suppress and would travel rapidly, [65] though Cold War scientific literature on the subject contradicts this. [34] Media coverage of the discovery would probably die down quickly, though, as scientists began to decipher the message and learn its true impact. [65] Different branches of government (for example legislative, executive, and judiciary) may pursue their own policies, potentially giving rise to power struggles. [93] Even in the event of a single contact with no follow-up, radio contact may prompt fierce disagreements as to which bodies have the authority to represent humanity as a whole. [43] Michaud hypothesizes that the fear arising from direct contact may cause nation-states to put aside their conflicts and work together for the common defense of humanity. [94]

Apart from the question of who would represent the Earth as a whole, contact could create other international problems, such as the degree of involvement of governments foreign to the one whose radio astronomers received the signal. [95] The United Nations discussed various issues of foreign relations immediately before the launch of the Voyager probes, [96] which in 2012 left the Solar System carrying a golden record in case they are found by extraterrestrial intelligence. [97] Among the issues discussed were what messages would best represent humanity, what format they should take, how to convey the cultural history of the Earth, and what international groups should be formed to study extraterrestrial intelligence in greater detail. [96]

According to Luca Codignola of the University of Genoa, contact with a powerful extraterrestrial civilization is comparable to occasions where one powerful civilization destroyed another, such as the arrival of Christopher Columbus and Hernán Cortés into the Americas and the subsequent destruction of the indigenous civilizations and their ways of life. [2] However, the applicability of such a model to contact with extraterrestrial civilizations, and that specific interpretation of the arrival of the European colonists to the Americas, have been disputed. [98] Even so, any large difference between the power of an extraterrestrial civilization and our own could be demoralizing and potentially cause or accelerate the collapse of human society. [43] Being discovered by a "superior" extraterrestrial civilization, and continued contact with it, might have psychological effects that could destroy a civilization, as is claimed to have happened in the past on Earth. [23]

Even in the absence of close contact between humanity and extraterrestrials, high-information messages from an extraterrestrial civilization to humanity have the potential to cause a great cultural shock. [70] Sociologist Donald Tarter has conjectured that knowledge of extraterrestrial culture and theology has the potential to compromise human allegiance to existing organizational structures and institutions. [70] The cultural shock of meeting an extraterrestrial civilization may be spread over decades or even centuries if an extraterrestrial message to humanity is extremely difficult to decipher. [70]

Legal Edit

Contact with extraterrestrial civilizations would raise legal questions, such as the rights of the extraterrestrial beings. An extraterrestrial arriving on Earth might only have the protection of animal cruelty statutes. [99] Much as various classes of human being, such as women, children, and indigenous people, were initially denied human rights, so might extraterrestrial beings, who could therefore be legally owned and killed. [100] If such a species were not to be treated as a legal animal, there would arise the challenge of defining the boundary between a legal person and a legal animal, considering the numerous factors that constitute intelligence. [101]

Freitas considers that even if an extraterrestrial being were to be afforded legal personhood, problems of nationality and immigration would arise. An extraterrestrial being would not have a legally recognized earthly citizenship, and drastic legal measures might be required in order to account for the technically illegal immigration of extraterrestrial individuals. [102]

If contact were to take place through electromagnetic signals, these issues would not arise. Rather, issues relating to patent and copyright law regarding who, if anyone, has rights to the information from the extraterrestrial civilization would be the primary legal problem. [99]

Scientific and technological Edit

The scientific and technological impact of extraterrestrial contact through electromagnetic waves would probably be quite small, especially at first. [103] However, if the message contains a large amount of information, deciphering it could give humans access to a galactic heritage perhaps predating the formation of the Solar System, which may greatly advance our technology and science. [103] A possible negative effect could be to demoralize research scientists as they come to know that what they are researching may already be known to another civilization. [103]

On the other hand, extraterrestrial civilizations with malicious intent could send information that could enable human civilization to destroy itself, [103] such as powerful computer viruses or information on how to make extremely potent weapons that humans would not yet be able to use responsibly. [43] While the motives for such an action are unknown, it would require minimal energy use on the part of the extraterrestrials. [103] According to Musso, however, computer viruses in particular will be nearly impossible unless extraterrestrials possess detailed knowledge of human computer architectures, which would only happen if a human message sent to the stars were protected with little thought to security. [44] Even a virtual machine on which extraterrestrials could run computer programs could be designed specifically for the purpose, bearing little relation to computer systems commonly used on Earth. [44] In addition, humans could send messages to extraterrestrials detailing that they do not want access to the Encyclopædia Galactica until they have reached a suitable level of technological advancement, thus mitigating harmful impacts of extraterrestrial technology. [44]

Extraterrestrial technology could have profound impacts on the nature of human culture and civilization. Just as television provided a new outlet for a wide variety of political, religious, and social groups, and as the printing press made the Bible available to the common people of Europe, allowing them to interpret it for themselves, so an extraterrestrial technology might change humanity in ways not immediately apparent. [104] Harrison speculates that a knowledge of extraterrestrial technologies could increase the gap between scientific and cultural progress, leading to societal shock and an inability to compensate for negative effects of technology. [104] He gives the example of improvements in agricultural technology during the Industrial Revolution, which displaced thousands of farm laborers until society could retrain them for jobs suited to the new social order. [104] Contact with an extraterrestrial civilization far more advanced than humanity could cause a much greater shock than the Industrial Revolution, or anything previously experienced by humanity. [104]

Michaud suggests that humanity could be impacted by an influx of extraterrestrial science and technology in the same way that medieval European scholars were impacted by the knowledge of Arab scientists. [105] Humanity might at first revere the knowledge as having the potential to advance the human species, and might even feel inferior to the extraterrestrial species, but would gradually grow in arrogance as it gained more and more intimate knowledge of the science, technology, and other cultural developments of an advanced extraterrestrial civilization. [105]

The discovery of extraterrestrial intelligence would have various impacts on biology and astrobiology. The discovery of extraterrestrial life in any form, intelligent or non-intelligent, would give humanity greater insight into the nature of life on Earth and would improve the conception of how the tree of life is organized. [106] Human biologists could learn about extraterrestrial biochemistry and observe how it differs from that found on Earth. [106] This knowledge could help human civilization to learn which aspects of life are common throughout the universe and which are specific to Earth. [106]

Ecological and biological-warfare impacts Edit

An extraterrestrial civilization might bring to Earth pathogens or invasive life forms that do not harm its own biosphere. [43] Alien pathogens could decimate the human population, which would have no immunity to them, or they might use terrestrial livestock or plants as hosts, causing indirect harm to humans. [43] Invasive organisms brought by extraterrestrial civilizations could cause great ecological harm because of the terrestrial biosphere's lack of defenses against them. [43]

On the other hand, pathogens and invasive species of extraterrestrial origin might differ enough from terrestrial organisms in their biology to have no adverse effects. [43] Furthermore, pathogens and parasites on Earth are generally suited to only a small and exclusive set of environments, [107] to which extraterrestrial pathogens would have had no opportunity to adapt.

If an extraterrestrial civilization bearing malice towards humanity gained sufficient knowledge of terrestrial biology and weaknesses in the immune systems of terrestrial biota, it might be able to create extremely potent biological weapons. [43] Even a civilization without malicious intent could inadvertently cause harm to humanity by not taking account of all the risks of their actions. [43]

According to Baum, even if an extraterrestrial civilization were to communicate using electromagnetic signals alone, it could send humanity information with which humans themselves could create lethal biological weapons. [43]


Apollo 11 Moon Landing Showed That Aliens Might Be More Than Science Fiction

On July 20, 1969, astronauts Neil Armstrong and Buzz Aldrin walked on Earth's moon for the first time in human history. Four days later, they — along with Apollo 11 command module pilot Michael Collins — were locked up on an American aircraft carrier in the middle of the Pacific Ocean.

The triumphant astronauts were in quarantine. Per a NASA safety protocol written half a decade earlier, the three lunar visitors were escorted directly from their splashdown site in the central Pacific to a modified trailer aboard the USS Hornet, where a 21-day isolation period began. The objective? To ensure that no potentially hazardous lunar microbes hitchhiked back to Earth with them. [5 Strange, Cool Things We've Recently Learned About the Moon]

Of course, as NASA quickly confirmed, there were no tiny aliens lurking in the astronauts' armpits or in the 50 pounds (22 kilograms) of lunar rocks and soil they had collected. But despite this absence of literal extraterrestrial life, the Apollo 11 astronauts still may have succeeded in bringing aliens back to Earth in another way that can still be felt 50 years later.

"Today, about 30 percent of the public thinks the Earth is being visited by aliens in saucers, despite the evidence of that being very poor," Seth Shostak, senior astronomer at the SETI Institute — a nonprofit research center focused on the search for alien life in the universe — told Live Science. "I think the moon landing had something to do with that."

Shostak has been searching for signs of intelligent life in the universe for most of his life (and, fittingly, shares a birthday with the Apollo 11 landing). Live Science recently spoke with him to find out more about how the moon landing changed the scientific community's pursuit of aliens and the world's perception of them. Highlights of our conversation (lightly edited for clarity) appear below.

LS: What did the moon landing teach humans about extraterrestrial life?

Seth Shostak: Not too much. By 1969, most scientists expected the moon was going to be dead.

They knew for 100 years that the moon had no atmosphere, because when stars pass behind the moon they just disappear if the moon had an atmosphere, stars would get dimmer as they got closer to the moon's edge. Plus, just look at the moon: There's no liquid, temperatures in the sun are hundreds of degrees, temperatures in the shade are minus hundreds of degrees — It's awful!

That said, I think the moon landing did affect the public perception of extraterrestrial life. Up until then, rockets and so forth were just science fiction. But the Apollo missions showed that you could travel from one world to another on a rocket — and maybe aliens could, too. I think that, from the public's point of view, this meant that going to the stars wasn't always going to be just fiction. Suddenly, the universe was a little more open.

LS: In 1969, did scientists think there might be aliens somewhere else in the solar system?

Shostak: Mars was the Great Red Hope, if you will, of extraterrestrial life in the solar system. People were very optimistic in 1976 when the Viking landers plopped down onto Mars that there would be life. Even Carl Sagan thought there might be critters with legs and heads running around there. Scientists were kind of disappointed when it didn't look like Mars had much life, either.

If you ask scientists today where's the best place to look for life in the solar system, they'll probably say Enceladus or one of the other moons of Jupiter or Saturn. There still could be microbial life on Mars, but to find it you'll have to dig a really deep hole and pull stuff up. Some of these moons, on the other hand, have geysers that shoot the material right into space, so you don't even have to land a spacecraft to find it.

LS: What did the search for extraterrestrial intelligence (SETI) look like around 1969?

Shostak: Modern SETI experiments began in 1960 with astronomer Frank Drake and his Project Ozma, where he searched for inhabited planets around two stars using a radio telescope. [After four years of searching, no recognizable signals were detected.]

But by 1969, SETI was being done informally by people who were working at telescopes, looking up the coordinates of nearby stars and hoping to pick up radio waves in their spare time. But it wasn't really organized until the NASA SETI program began in the 1970s. It was a serious program that, at one point, had a budget of $10 million a year, so NASA could build special receivers, get telescope time and all that sort of stuff.

The NASA SETI program began observing in 1992 — and, in 1993, Congress killed it! Ultimately, a democratic congressman from Nevada killed it. I find it ironic that a congressman from Nevada — home of Area 51 and the extraterrestrial highway — voted down the NASA SETI program, when they profit more from the public fascination with aliens that anywhere else.


THE HUNT FOR LIFE BEYOND EARTH

Astrobiologist Kevin Hand prepares to deploy a rover beneath the ice of Alaska's Sukok Lake. When a probe finally reaches Europa, its search for life may be modeled on trial runs like this. And with the powerful SLS rocket NASA is designing, he says, "we could potentially get to Jupiter and Europa very quickly."

By Michael D. Lemonick Photographs by Mark Thiessen

By Michael D. Lemonick Photographs by Mark Thiessen

An electronic signal travels from NASA's Jet Propulsion Lab in Pasadena, California, to a robotic rover clinging to the underside of foot-thick ice on an Alaskan lake. The rover's spotlight begins to glow. "It worked!" exclaims John Leichty, a young JPL engineer huddled in a tent on the lake ice nearby. It may not sound like a technological tour de force, but this could be the first small step toward the exploration of a distant moon.

More than 4,000 miles to the south, geomicro­biologist Penelope Boston sloshes through murky, calf-deep water in a pitch-dark cavern in Mexico, more than 50 feet underground. Like the other scientists with her, Boston wears an industrial-strength respirator and carries a canister of spare air to cope with the poisonous hydrogen sulfide and carbon monoxide gases that frequently permeate the cave. The rushing water around her feet is laced with sulfuric acid. Suddenly her headlamp illuminates an elongated droplet of thick, semitransparent fluid oozing from the chalky, crumbling wall. "Isn't it cute?" she exclaims.

These two sites—a frozen Arctic lake and a to­xic tropical cave—could provide clues to one of the oldest, most compelling mysteries on Earth: Is there life beyond our planet? Life on other worlds, whether in our own solar system or orbiting distant stars, might well have to survive in ice-covered oceans, like those on Jupiter's moon Europa, or in sealed, gas-filled caves, which could be plentiful on Mars. If you can figure out how to isolate and identify life-forms that thrive in similarly extreme surroundings on Earth, you're a step ahead in searching for life elsewhere.

It's difficult to pin down when the search for life among the stars morphed from science fiction to science, but one key milestone was an astronomy meeting in November 1961. It was organized by Frank Drake, a young radio astro­nomer who was intrigued with the idea of searching for alien radio transmissions.

When he called the meeting, the search for extraterrestrial intelligence, or SETI, "was essentially taboo in astronomy," Drake, now 84, remembers. But with his lab director's blessing, he brought in a handful of astronomers, chemists, biologists, and engineers, including a young planetary scientist named Carl Sagan, to discuss what is now called astrobiology, the science of life beyond Earth. In particular, Drake wanted some expert help in deciding how sensible it might be to devote significant radio telescope time to listening for alien broadcasts and what might be the most promising way to search. How many civilizations might reasonably be out there? he wondered. So before his guests arrived, he scribbled an equation on the blackboard.

That scribble, now famous as the Drake equation, lays out a process for answering his question. You start out with the formation rate of sunlike stars in the Milky Way, then multiply that by the fraction of such stars that have planetary systems. Take the resulting number and multiply that by the number of life-friendly planets on average in each such system—planets, that is, that are about the size of Earth and orbit at the right distance from their star to be hospitable to life. Multiply that by the fraction of those planets where life arises, then by the fraction of those where life evolves intelligence, and then by the fraction of those that might develop the technology to emit radio signals we could detect.

Astronomer Frank Drake helped found the science of astrobiology in the 1960s by searching for radio broadcasts from alien civilizations. Now 84, he's got a new target: flashes from alien light sources. "We know how to do SETI much better these days," he says. "Our biggest challenge is coming up with the funding."

The final step: Multiply the number of radio-savvy civilizations by the average time they're likely to keep broadcasting or even to survive. If such advanced societies typically blow themselves up in a nuclear holocaust just a few dec­ades after developing radio technology, for example, there would probably be very few to listen for at any given time.

The equation made perfect sense, but there was one problem. Nobody had a clue what any of those fractions or numbers were, except for the very first variable in the equation: the formation rate of sunlike stars. The rest was pure guesswork. If SETI scientists managed to snag an extraterrestrial radio signal, of course, these uncertainties wouldn't matter. But until that happened, experts on every item in the Drake equation would have to try to fill it in by nailing down the numbers—by finding the occurrence rate for planets around sunlike stars or by trying to solve the mystery of how life took root on Earth.

It would be a third of a century before scientists could even begin to put rough estimates into the equation. In 1995 Michel Mayor and Didier Queloz of the University of Geneva detected the first planet orbiting a sunlike star outside our solar system. That world, known as 51 Pegasi b, about 50 light-years from Earth, is a huge, gaseous blob about half the size of Jupiter, with an orbit so tight that its "year" is only four days long and its surface temperature close to 2000°F.

Nobody thought for a moment that life could ever take hold in such hellish conditions. But the discovery of even a single planet was an enormous breakthrough. Early the next year Geoffrey Marcy, then at San Francisco State University and now at UC Berkeley, would lead his own team in finding a second extrasolar planet, then a third. After that, the floodgates opened. To date, astronomers have confirmed nearly two thousand so-called exoplanets, ranging in size from smaller than Earth to bigger than Jupiter thousands more—most found by the exquisitely sensitive Kepler space telescope, which went into orbit in 2009—await confirmation.

None of these planets is an exact match for Earth, but scientists are confident they'll find one that is before too long. Based on the discoveries of somewhat larger planets made to date, astronomers recently calculated that more than a fifth of stars like the sun harbor habitable, Earthlike planets. Statistically speaking, the nearest one could be a mere 12 light-years away, which is practically next door in cosmic terms.

That's good news for astrobiologists. But in recent years planet hunters have realized that there's no reason to limit their search to stars just like our sun. "When I was in high school," says David Charbonneau, an astronomer at Harvard, "we were taught that Earth orbits an average star. But that's a lie." In fact, about 80 percent of the stars in the Milky Way are small, cool, dim, reddish bodies known as M dwarfs. If an Earthlike planet circled an M dwarf at the right distance—it would have to be closer in than the Earth is to our sun to avoid being too cold—it could provide a place where life could gain a foothold just as easily as on an Earthlike planet orbiting a sunlike star.

Moreover, scientists now believe a planet doesn't have to be the same size as Earth to be habitable. "If you ask me," says Dimitar Sasselov, another Harvard astronomer, "anywhere from one to five Earth masses is ideal." In short, the variety of habitable planets and the stars they might orbit is likely to be far greater than what Drake and his fellow conferees conservatively assumed at that meeting back in 1961.

That's not all: It turns out that the range of temperatures and chemical environments where extremophilic organisms might be able to thrive is also greater than anyone at Drake's meeting could have imagined. In the 1970s oceanographers such as National Geographic Explorer-in-Residence Robert Ballard discovered superheated gushers, known as hydrothermal vents, nourishing a rich ecosystem of bacteria. Feasting on hydrogen sulfide and other chemicals dissolved in the water, these microbes in turn feed higher organisms. Scientists have also found life-forms that flourish in hot springs, in frigid lakes thousands of feet below the surface of the Antarctic ice sheet, in highly acidic or highly alkaline or extremely salty or radioactive locations, and even in minute cracks in solid rock a mile or more underground. "On Earth these are niche environments," says Lisa Kaltenegger, who holds joint appointments at Harvard and the Max Planck Institute for Astronomy in Heidelberg, Germany. "But on another planet you can easily envision that they could be dominant scenarios."

The one factor that biologists argue is critical for life as we know it is water in liquid form—a powerful solvent capable of transporting dissolved nutrients to all parts of an organism. In our own solar system we've known since the Mariner 9 Mars orbiter mission in 1971 that water once likely flowed freely on the red planet. So life might have existed there, at least in microbial form—and it's plausible that remnants of that life could still endure underground, where liquid water may linger. Jupiter's moon Europa also shows cracks in its relatively young, ice-covered surface—evidence that beneath the ice lies an ocean of liquid water. At a half billion miles or so from the sun, Europa's water should be frozen solid. But this moon is constantly flexing under the tidal push and pull of Jupiter and several of its other moons, generating heat that could keep the water below liquid. In theory, life could exist in that water too.

In 2005 NASA's Cassini spacecraft spotted jets of water erupting from Saturn's moon Enceladus subsequent measurements by the spacecraft reported in April of this year confirm an underground source of water on that moon as well. Scientists still don't know how much water might be under Enceladus's icy shell, however, or whether it's been liquid long enough to permit life to exist. The surface of Titan, Saturn's largest moon, has rivers, lakes, and rain. But Titan's meteorological cycle is based on liquid hydrocarbons such as methane and ethane, not water. Something might be alive there, but what it would be like is very hard to guess.

Mars is far more Earthlike, and far closer, than any of these distant moons. The search for life has driven virtually every mission to the red planet. The NASA rover Curiosity is currently exploring Gale crater, where a huge lake sat billions of years ago and where it's now clear that the chemical environment would have been hospitable to microbes, if they existed.

A cave in Mexico isn't Mars, of course, and a lake in northern Alaska isn't Europa. But it's the search for extraterrestrial life that has taken JPL astrobiologist Kevin Hand and the other members of his team, including John Leichty, to Sukok Lake, 20 miles from Barrow, Alaska. The same quest has lured Penelope Boston and her colleagues multiple times to the poisonous Cueva de Villa Luz, a cave near Tapijulapa in Mexico. Both sites let the researchers test new techniques for searching for life in environments that are at least broadly similar to what space probes might encounter. In particular, they're looking for biosignatures—­visual or chemical clues that signal the presence of life, past or present, in places where scientists won't have the luxury of doing sophisticated laboratory experiments.

Take the Mexican cave. Orbiting spacecraft have shown that caves do exist on Mars, and they're just the sorts of places where microbes might have taken refuge when the planet lost its atmosphere and surface water some three billion years ago. Such Martian cave dwellers would have had to survive on an energy source other than sunlight—like the dripping ooze that has Boston so enchanted. The scientists refer to these unlovely droplets as "snottites." One of thousands in the cave, varying in length from a fraction of an inch to a couple of feet, it does look uncannily like mucus. It's actually a biofilm, a community of microbes bound together in a viscous, gooey blob.

The snottite microbes are chemotrophs, Boston explains. "They oxidize hydrogen sulfide—­that's their only energy source—and they produce this goo as part of their lifestyle."

Snottites are just one of the microbial communities that exist here. Boston, of the New Mexico Institute of Mining and Technology and the National Cave and Karst Research Institute, says that all told there are about a dozen communities of microbes in the cave. "Each one has a very distinct physical appearance. Each one is tapping into different nutrient systems."

One of these communities is especially intriguing to Boston and her colleagues. It doesn't form drips or blobs but instead makes patterns on the cave walls, including spots, lines, and even networks of lines that look almost like hieroglyphics. Astrobiologists have come to call these patterns biovermiculations, or bioverms for short, from the word "vermiculation," meaning decorated with "irregular patterns of lines, as though made by worm tracks."

Microbe-rich biofilms—referred to as snottites—drip from the sunless walls of Cueva de Villa Luz in Mexico. Living off sulfur compounds, the microbes in turn feed midges that live in the cave.

It turns out that patterns like these aren't made only by microorganisms growing on cave walls. "It happens on a variety of different scales, usually in places where some resource is in short supply," says Keith Schubert, a Baylor University engineer who specializes in imaging systems and who came to Cueva de Villa Luz to set up cameras for long-term monitoring inside the cave. Grasses and trees in arid regions create bioverm patterns as well, says Schubert. So do soil crusts, which are communities of bacteria, mosses, and lichens that cover the ground in deserts.

If this hypothesis holds up—and it's still only a hypothesis—then Boston, Schubert, and other scientists who are documenting bioverms may have found something crucially important. Until now, many of the markers of life astrobiologists have looked for are gases, like oxygen, that are given off by organisms on Earth. But life that produces an oxygen biosignature may be only one kind among many.

"What excites me about bioverms," says Boston, "is that we've seen them at all these different scales and in all these wildly different environments, and yet the characters of the patterns are very similar." It's highly plausible, she and Schubert believe, that these patterns, based on simple rules of growth and competition for resources, could be literally a universal signature of life. In caves, moreover, even when the microbial communities die, they leave the patterns behind. If a rover should see something like this on the wall of a Martian cave, says Schubert, "it could direct you where to focus your attention."

At the opposite end of North America, the scientists and engineers shivering at Sukok Lake are on a similar mission. They're working at two different locations on the lake, one next to a cluster of three small tents the scientists have dubbed "Nasaville," and the other, with just a single tent, about a half mile away as the crow flies. Because methane gas bubbling from the lake bottom churns up the water, ice has a hard time forming in some places. To snowmobile from one camp to the other, the scientists have to take a curving, indirect route to avoid a potentially fatal dunking.

It was the methane that first drew the scientists to Sukok and other nearby Alaska lakes back in 2009. This common hydrocarbon gas is generated by microbes, known collectively as methanogens, that decompose organic matter, making it another potential biosignature astrobiologists could look for on other worlds. But methane also comes from volcanic eruptions and other nonbiological sources, and it forms naturally in the atmosphere of giant planets like Jupiter as well as on Saturn's moon Titan. So it's crucial that scientists be able to distinguish biological methane from its nonbiological cousin. If you're focused on ice-covered Europa, as Kevin Hand is, ice-covered, methane-rich Sukok Lake isn't a bad place to get your feet wet—as long as you don't do it literally.

Cold Case Astrobiologist Kevin Hand talks about the rover and its trial run in Alaska.

Hand, a National Geographic emerging explorer, favors Europa over Mars as a place to do astrobiology, for one key reason. Suppose we do go to Mars, he says, and find living organisms in the subsurface that are DNA based, like life on Earth. That could mean that DNA is a universal molecule of life, which is certainly possible. But it could also mean that life on Earth and life on Mars share a common origin. We know for certain that rocks blasted off the surface of Mars by asteroid impacts have ended up on Earth. It's also likely that Earth rocks have traveled to Mars. If living microbes were trapped inside such spacefaring rocks and survived the journey, which is at least plausible, they could have seeded whichever planet they ended up on. "If life on Mars were found to be DNA based," says Hand, "I think we would have some confusion as to whether or not that was a separate origin of DNA." But Europa is vastly farther away. If life were found there, it would point to a second, independent origin—even if it were DNA based.

Europa certainly seems to have the basic ingredients for life. Liquid water is abundant, and the ocean floor may also have hydrothermal vents, similar to Earth's, that could provide nutrients for any life that might exist there. Up at the surface, comets periodically crash into Europa, depositing organic chemicals that might also serve as the building blocks of life. Particles from Jupiter's radiation belts split apart the hydrogen and oxygen that makes up the ice, forming a whole suite of molecules that living organisms could use to metabolize chemical nutrients from the vents.

The big unknown is how those chemicals could make it all the way down through the ice, which is probably 10 to 15 miles thick. The Voyager and Galileo missions made it clear, however, that the ice is riddled with cracks. Early in 2013 Hand and Caltech astronomer Mike Brown used the Keck II telescope to show that salts from Europa's ocean were likely making their way to the surface, possibly through some of those cracks. And late in 2013 another team of observers, using the Hubble Space Telescope, reported plumes of liquid water spraying from Europa's south pole. Europa's ice is evidently not impenetrable.

This makes the idea of sending a probe to orbit Europa all the more compelling. Unfortunately the orbiter mission the National Research Council evaluated in its 2011 report was deemed scientifically sound but, at $4.7 billion, too expensive. A JPL team led by Robert Pappalardo went back to the drawing board and reimagined the mission. Their Europa Clipper probe would orbit Jupiter, not Europa, which would require less propellant and save money, but it would make something like 45 flybys of the moon in an attempt to understand its surface and atmospheric chemistry, and indirectly the chemistry of the ocean.

All told, Pappalardo says, the redesigned mission should come in at under two billion dollars over its whole life span. If the mission concept goes forward, he says, "we envision a launch sometime in the early to mid 2020s." If that launch takes place aboard an ­Atlas V rocket, the trip to Europa will take about six years. "But it's also possible," he says, "that we could launch on the new SLS, the Space Launch System, that NASA is currently developing. It's a big rocket, and with that we could get there in 2.7 years."

BRUIE (Buoyant Rover for Under-Ice Exploration) crawls along the underside of the surface ice in a test in Sukok Lake. Bubbles of methane and other compounds signal the presence of life below.

The Clipper likely wouldn't be able to find life on Europa, but it could help make the case for a follow-up lander that could dig into the surface, studying its chemistry the way rovers have studied Mars's. The Clipper could also scout out the best places for such a lander to set down. The next logical step after a lander—sending a probe down to explore Europa's ocean—could be a lot tougher, depending on how thick the ice is. As an alternative, mission scientists might try to reach a lake that may be entirely contained within the ice near the surface. "When that undersea explorer eventually does come to fruition," says Hand, "in evolutionary terms, it'll be like Homo sapiens to the Australopithecus we've been testing in Alaska."

The relatively crude rover Hand and his crew are testing at Sukok Lake crawls along under a foot of ice, its built-in buoyancy keeping it firmly pressed against the frozen subsurface, sensors measuring the temperature, salinity, pH, and other characteristics of the water. It doesn't look for organisms directly, however that's currently the job of the scientists working on another aspect of Hand's project across the lake, including John Priscu of Montana State University, who last year extracted living bacteria from Lake Whillans, half a mile under the West Antarctic ice sheet. Along with geobiologist Alison Murray, of the Desert Research Institute in Reno, Nevada, and her graduate student Paula Matheus-Carnevali, Priscu is investigating what characteristics frigid environments need to make them friendly to life and what sorts of organisms actually live there.

Useful as the study of extremophiles is to contemplating the nature of life beyond our planet, it can only provide terrestrial clues to an extraterrestrial mystery. Soon, however, we will have other means to fill in missing parts of the Drake equation. NASA has approved a new planet-hunting telescope known as the Transiting Exoplanet Survey Satellite. Scheduled to launch in 2017, TESS will look for planets around our nearest neighboring stars, finding targets for astrophysicists searching planetary atmospheres for biosignature gases. The James Webb Space Telescope, scheduled for a 2018 launch, will make those searches far easier than they are today— although recent observations with the Hubble, including the discovery of clouds on a super-Earth known as GJ 1214b, make it clear that nobody is sitting around waiting for the Webb.

Some astrobiologists are even investigating a possibility that sounds more like science fiction than science. All of the focus on biosignatures and extremophiles assumes that life on other worlds, like life on Earth, will be built from complex molecules that incorporate carbon as an essential part of their structures—and use water as a solvent. One reason is that carbon and water are abundant throughout the Milky Way. Another is that we don't know how to look for noncarbon life, since we don't know what biosignatures it might leave.

"If we limit our search this way, we could fail," says Harvard's Sasselov. "We need to make an effort to understand at least some of the alternatives and what their atmospheric signatures might be." So Sasselov's group at Harvard is looking at alternate biologies that could plausibly exist on distant worlds, where, for instance, a sulfur cycle might replace the carbon cycle that dominates terrestrial biology.

In the background of all this research is the project that got astrobiology started more than half a century ago. Although he's technically retired, Frank Drake is still looking for extraterrestrial signals—a discovery that would trump everything else. Though Drake is frustrated that the funding for SETI has mostly dried up, he's excited about a brand-new project that would try to detect flashes of light, rather than radio transmissions, from alien civilizations. "It's wise to try every possible approach," he says, "because we're not very good at psyching out what extraterrestrials might actually be doing."

Michael Lemonick's latest book is Mirror Earth: The Search for Our Planet's Twin . Mark Thiessen shot our story on the solar system in the July 2013 issue.

Society Grant: Penelope Boston's research was funded in part by your Society membership.

Distant Oasis

Europa's frozen fissured surface, seen here in a colorized moasic image from the Galileo spacecraft, hides a liquid ocean that may hold all the ingredients needed for life.

Goldilocks Worlds

Of the 1,780 confirmed planets beyond our solar system, as many as 16 are located in their star's habitable zone, where conditions are neither too hot nor too cold to support life.

1996-2014 NATIONAL GEOGRAPHIC SOCIETY. ALL RIGHTS RESERVED TERMS OF SERVICE PRIVACY POLICY


Extremophiles: a special or general case in the search for extra-terrestrial life?

Since time immemorial life has been viewed as fragile, yet over the past few decades it has been found that many extreme environments are inhabited by organisms known as extremophiles. Knowledge of their emergence, adaptability, and limitations seems to provide a guideline for the search of extra-terrestrial life, since some extremophiles presumably can survive in extreme environments such as Mars, Europa, and Enceladus. Due to physico-chemical constraints, the first life necessarily came into existence at the lower limit of its conceivable complexity. Thus, the first life could not have been an extremophile furthermore, since biological evolution occurs over time, then the dual knowledge regarding what specific extremophiles are capable of, and to the analogue environment on extreme worlds, will not be sufficient as a search criterion. This is because, even though an extremophile can live in an extreme environment here-and-now, its ancestor however could not live in that very same environment in the past, which means that no contemporary extremophiles exist in that environment. Furthermore, a theoretical framework should be able to predict whether extremophiles can be considered a special or general case in the galaxy. Thus, a question is raised: does Earth's continuous habitability represent an extreme or average value for planets? Thus, dependent on whether it is difficult or easy for worlds to maintain the habitability, the search for extra-terrestrial life with a focus on extremophiles will either represent a search for dying worlds, or a search for special life on living worlds, focusing too narrowly on extreme values.

Keywords: Astrobiology Biological evolution Complexity distribution Inhabitability.


China Joins the Search for Extra-Terrestrial Life - History

Most of Chinese history can be divided up into a series of dynasties from the start of the Xia dynasty in 2205 BCE to the end of the Qing dynasty in 1912 CE. You can go here to learn more about Ancient China.

Xia Dynasty (2205 to 1575)

Shang Dynasty (1570 to 1045)

  • 771 - Start of the Spring and Autumn Period and the rise if the Eastern Zhou.
  • 551 - The Chinese philosopher Confucius is born. His thoughts and ideas will have a great impact on the culture of China.


  • 221 - The first emperor of China, Emperor Qin, unites all of China under one rule.
  • 220 - Construction on the Great Wall of China begins in an effort to keep out the Mongols.
  • 210 - Emperor Qin dies and is buried with the Terra Cotta Army.
  • 207 - The Chinese Civil Service is established to help run the government.
  • 104 - The Chinese Calendar is defined.
  • 105 - Paper is invented by Cai Lun.
  • 208 - The Battle of Red Cliffs occurs.
  • 250 - The religion of Buddhism is introduced. It will become one of the three main religions of China.
  • 609 - The Grand Canal is finished.
  • 868 - The first use of wood block printing to print a book.
  • 1044 - Gunpowder is invented. It is first used for fireworks.
  • 1088 - The Chinese invent the magnetic compass.
  • 1200 - The Mongol tribes are united under Genghis Khan. He begins his conquest of northern China.
  • 1279 - Mongol leader Kublai Khan defeats the Chinese and takes control of the land. He forms his own dynasty called the Yuan dynasty.
  • 1405 - Explorer Zheng He makes his first journey to India and Africa. The construction on the Forbidden City begins.
  • 1420 - Beijing is made capital of China.
  • 1517 - The Portuguese arrive and establish trade with China.


  • 1900 - The Boxer Rebellion occurs with violence against foreigners and Christians. International forces intervene.
  • 1908 - Puyi becomes the last Emperor of China at the age of 2.
  • 1910 - Slavery is abolished in China.
  • 1911 - The Qing dynasty is overthrown by the Xinhai Revolution.
  • 1912 - Revolutionary Sun Yat-sen becomes the first President of the Republic of China.
  • 1912 - China adopts the Gregorian Calendar.
  • 1917 - China joins World War I and declares war on Germany.
  • 1927 - The Ten Years Civil War occurs between the Kuomintang nationalists, led by Chiang Kai-shek, and the communist party, led by Mao Zedong.
  • 1928 - Chiang Kai-shek becomes the Chairman of the National Government of China.
  • 1934 - Mao Zedong leads his people on a retreat across China called the Long March.
  • 1937 - China is invaded by Japan. Japan captures several important cities including Beijing.
  • 1941 - Japan attacks the United States at Pearl Harbor. China is now on the side of the Allies in World War II.
  • 1945 - World War II comes to an end and Japan is defeated. The Civil War between the communists and the nationalists resumes.


  • 1949 - The communists win the war and the People's Republic of China is formed by Mao Zedong.
  • 1949 - The nationalists flee to Taiwan and set up their government.
  • 1958 - Beginning of the "Great Leap Forward." The plan fails and millions starve to death.
  • 1964 - China develops a nuclear bomb.
  • 1966 - Mao begins his "Cultural Revolution" in which over one million people are killed.
  • 1972 - President Richard Nixon visits China.
  • 1974 - The Terra Cotta Warriors are discovered.
  • 1984 - The communist party allows for economic reforms with less government involvement in business.
  • 1997 - The United Kingdom hands over control of Hong Kong to China.
  • 2006 - The Three Gorges Dam is completed.
  • 2008 - The summer Olympics are held in Biejing.
  • 2010 - China becomes the world's second largest economy behind the United States.

China's history is rich with art, politics, science, and philosophy. It is home to the oldest of the major world civilizations.

China was ruled by various dynasties for much of its history. The first dynasty is believed to be the Xia dynasty which formed somewhere around 2250 BC. The Shang or Yin dynasty gained power around the 14th century BC. The Han Dynasty, which lasted over 400 years from 206 BC to 220 AD, was one of the most influential in China's history. Much of the culture today was created during the Han Dynasty. Later famous dynasties, like the Song and the Tang, continued to refine the culture and bring new innovations to the world including printed money, a permanent navy, and a complex government that ruled over 100 million people.


The last of the great dynasties, the Qing Dynasty, began in 1644. The Ming Dynasty was in power, but was overthrown by the Manchus who put the Qing dynasty into power. During the Qing dynasty, western influences, European trade, and a number of wars all served to weaken China. Great Britain gained control of Hong Kong after the Opium Wars.

In the early 1900s the people of China began to want reform. Revolutionary leader Sun Yat-sen created the Chinese Nationalist Peoples Party, also called the KMT or Kuomintang. After Sun Yat-sen died, Chiang Kai-shek became leader of the party. However, Chiang turned on the leaders of the CCP, the communist party, and had many of them killed. The Chinese Civil War broke out between the KMT and the communists. A new leader, Mao Zedong took over the communists and led the CCP on a famous "Long March" to a distant area of China. There they regrouped and eventually gained the strength to force Chiang Kai-shek out of China and to the island of Taiwan.

Mao Zedong established the Peoples Republic of China on October 1, 1949. This new government was strongly allied with the Soviet Union and modeled its government after Soviet communism.

In 1958, Mao Zedong embarked on a new plan called the Great Leap Forward. Unfortunately, this plan backfired and China experienced a terrible famine including much starvation and death. Over the next several decades China would struggle with political reforms and economic policy, slowly recovering and becoming a major world power again. Today, China is a major world power and the second largest economy in the world.