From highly trained scientists toiling away at research institutes to amateur enthusiasts gazing upward from their backyards, humanity boasts no shortage of people looking for life beyond Earth. Add to that the massive size of the universe — estimates range in the trillions of galaxies — and probability dictates that we should have already encountered another species by now.
And yet, we still have no evidence that we aren’t alone in the universe.
However, according to astronomy researcher Chris Impey, this hunt for life beyond Earth may soon yield results. In an interview with Futurism, he revealed that he believes that we are less than two decades away from finding extraterrestrial life…but it may not be the kind of life we were hoping for: “I put my money on detecting microbial life in 10 to 15 years, but not at all detecting intelligent life.”
Hide and Seek on a Cosmic Level
While Impey is skeptical that intelligent life is within our sights, he does have a couple of suggestions as to where we should focus our search for extraterrestrial lifeforms, intelligent or not. The first is our own backyard, or, more accurately, our own solar system.
While Impey tells Futurism he doesn’t rule out the possibility that life still exists on Mars, he says that those lifeforms are likely below the surface and are, therefore, much harder to detect. As such, he asserts that we have a better chance of finding evidence of life that used to exist on the Red Planet: “If we actually get Mars rocks back here to Earth from a place that we think could have been habitable in the past, then we might find evidence of prior life.”
Other bodies in our solar system could potentially host life as well, according to Impey, including the water world Europa (one of Jupiter’s several moons). He thinks future missions targeting the satellite could yield helpful—if not entirely conclusive—results, asserting that they should at least give us “some better idea if that ocean could have life in it.”
Of course, our solar system is just one very small corner of a very massive universe, so we’d be remiss if we didn’t look beyond it for signs of life. To narrow down the scope of our search, Impey suggests targeting the many exo-Earths we’ve already uncovered. Instead of focusing on the planets’ surfaces, though, we should research their atmospheres.
In the next few years, we’ll be able to use the James Web Space Telescope and other detection devices to look for biomarkers such as oxygen and methane in the atmospheres of these Earth-like planets, says Impey. “This biomarker experiment…could find evidence of microbial life indirectly,” he explains. The research should help us pinpoint the planets that are “the closest to Earth as possible, not in distance, but in character,” he adds, and since Earth is the only place we know life exists, finding the most Earth-like planets is our best bet for finding life.
Any Life Is Better Than No Life
Even if Impey is right, and humanity is still decades away from finding intelligent alien life, the discovery of microbial life on Mars, Europa, or one of the thousands of exoplanets we’ve identified would still be a huge development. It would mean Earth isn’t unique, that something else living is out there.
We could use the knowledge we glean from studying this microbial life to narrow down our hunt for other, more complex organisms. By providing valuable insights into how other living beings are able to survive on worlds far different from our own, this microbial life could help in our quest to become a multi-planetary species. Even the discovery of past microbial life would be helpful, as it could serve as something of a cautionary tale, providing us with the opportunity to learn and ensure we don’t meet the same fate.
As Impey notes, thanks to dramatic advances in technology, we’ve never been better equipped to discover life beyond Earth than we are right now: “Every new SETI experiment done now is about as good as the sum of all previous SETI experiments put together.”
However, even if all of the currently planned experiments and missions came up short, Impey doesn’t envision humanity giving up the hunt for extraterrestrial life any time soon: “The first SETI experiment was in 1959, so obviously it has been going on for over half a century without any success. The people who do it don’t seem put off by failure.”
This interview has been slightly edited for clarity and brevity.
Both the most cynical person on Earth and the world’s greatest optimist could easily look at everything around them and ask: could this truly be all there is in the universe? Whatever your reason for posing the question, you may have an answer sooner than you think — and that answer is likely to be “no.” Science writer and comedian Ben Miller posits in his book The Aliens Are Coming! The Extraordinary Science Behind Our Search for Life in the Universe that one of the most powerful forces shaping science today is the growing search for life in the universe fueled by the belief that we are not alone. He believes that because of our current technologies, we’ll know about life on the Earth-like planets closest to us within the next ten years.
It’s easy to see why he thinks so. Scientists have identified an exoplanet that they’ve described as the best candidate for life as we know it — perhaps an even more important a target for planet characterization within habitable zones in the future than either Proxima b or TRAPPIST-1, and these have also recently been discovered. Speaking of Proxima b, the James Webb Telescope is likely to give us the images that will clarify its potential for supporting life, as it will do for other exoplanets.
In recent months scientists have stated that the fast radio bursts we’ve intercepted from outer space may well be evidence of alien life. Now they’re working to discern whether alien technology could be their source. Scientists also now believe that life might exist on Europa, one of Jupiter’s four Galilean moons. Recently, NASA’s plans to send a lander in search of biosignatures that might signal the presence of extraterrestrial life within its warm core have sprung into action; Europa may be home to a subterranean ocean, making it an ideal place to search for alien life.
In 2016, researchers made improvements to the Atacama Large Millimeter/submillimeter Array that could make finding water on celestial bodies easier. These improvements were specifically directed toward the ongoing search for alien life, as was the partnership between Breakthrough Initiative to find alien life and the National Astronomical Observatories of China. China’s team uses the 488 meter (1,600 foot) FAST telescope, and now it is being used in partnership with the world’s other largest radio telescopes, including the Parkes Observatory in Australia and the Green Bank Telescope in the US, to seek out extraterrestrial life. In 2016 scientists also adopted more accurate methods for studying gravitational pull of distant stars, making it easier to gather data on the size and brightness of the star, the likelihood of water oceans, and possibility of life being present.
An Utterly Changed Humanity
Why are we so enthralled with this search for other life in the universe? It’s far more than an AV geek, sci-fi con hangover, if that’s your suspicion. Contact could mean extraordinary things for humanity if it happens soon — some of the possibilities are daunting, but most of them are promising.
Stephen Hawking is one of the best-known and most reputable voices who cautions against making first contact with alien life. His argument is simply that we have no way of knowing what’s out there, and that, historically speaking, as more advanced civilizations have come into contact with less advanced cultures, the latter has typically been oppressed and aggressed against, the former seeing it as less valuable. However, it’s worth noting that when we speak historically we are, by necessity, limited to our own recorded human history. What we’re observing may not be a pattern common to all life; it may simply be a pattern common to human cultures.
In contrast, the SETI (Search for Extra Terrestrial Intelligence) Institute is populated by people who feel we have little, if anything, to lose by seeking out other forms of life. SETI has now given birth to METI International (Messaging Extra Terrestrial Intelligence), which is actively seeking out contact. Douglas Vakoch, a professor in the Department of Clinical Psychology at the California Institute for Integral Studies and the president of METI International, strongly disagrees with Hawking. He thinks it is illogical to hide our existence as a species since we have already leaked transmissions from radio and television broadcasts in the form of electromagnetic radiation for almost 100 years. Vakoch concludes that any culture with the technological sophistication to master interstellar travel can already perceive our leaked signals, and are therefore already aware of us, waiting for us to make the first move.
METI, led by Vakoch, is now working to target star systems within 20 or 30 light-years with repeat messages as part of an effort to accumulate data in order to test the Fermi Paradox and the Zoo Hypothesis. Ideally, within a few decades, Vakoch and his team hope that they will generate a testable hypothesis with enough data and standard peer-review methods.
As for Miller, he’s not on Team Hawking, and thinks that the benefits of contact outweigh the risks. The potential to learn about advanced technology for space travel, repairing our planet’s environment, and many other applications is an obvious benefit to contact. For Neil deGrasse Tyson, the big benefit to contact is more profound: right now, our understanding of life is extremely limited, and that is because we only have our own, terrestrial sample of life to study. The notion that we have an understanding of the tremendous diversity of life is somewhat silly when you think of it in this context; our entire set of observations all share a single origin and an encoded existence that transmits heredity and mediates replication via nucleic acids.
Our current understanding of life is too much like the infamous legal definition of pornography — the classic “I know it when I see it” — which, for Tyson, lacks scientific rigor (and to clarify, he is not responsible for that icky analogy). But our explorations of the galaxy to find contact with other forms of life could give us other examples and samples, and a truer sense of what life truly is. This kind of knowledge has the potential to change everything else we think we know, most likely for the better.
From the pointy ears of Vulcans to the sharp fangs of the Xenomorph, humans have long envisioned what alien species must be like. Will they be humanoid, or completely unfamiliar? Friendly, or violent?
We have no evidence of what extraterrestrials are like — or if they exist to begin with — but that hasn’t stopped us from looking for them. For years, organizations like SETI and NASA have been scouring the galaxy and our solar system for signs of alien life — and have actually found a few. Some scientists say fast radio bursts could be explained by otherworldly intelligence, and NASA just announced that they have detected molecules that could suggest life on one of Saturn’s moons.
Despite our many creative tests, we have yet to discover conclusive proof of life originating from another world. And perhaps this is for the best, as, for the moment, Earth has not come to a consensus on how to react to alien lifeforms — or if we should even interact with them at all.
While humanity has not developed a protocol for alien encounters, we do have a a scale, called the “Rio Scale,” for determining how important your evidence of aliens is. It was developed by researchers at SETI and evaluates your discovery based on four criteria. It calculates your score (available here for the next time you spot a UFO), which can range from zero (you think you see stars forming your initials in a NASA picture of a distant galaxy, but no one else gets how important that is) to 10 (you have an alien in the trunk of your car, and are now Googling labs to take it to).
But the question remains, what do we do when we finally reach that 10 — or even a 5? Do we send flowers? Try to initiate trade? Put on a tough front and warn off the potentially dangerous aliens?
While we haven’t officially arrived at an answer to these questions, enthusiasts haven’t let that stop them. Several groups have already sent messages to the stars, hoping to get an extraterrestrial response. NASA included a map to Earth in the Pioneer spacecraft. Carl Sagan helped broadcast a message in “alienese” from the Arecibo Observatory. We have also sent mathematical principles to potentially-habitable star systems so aliens will know that we’re smart.
But many experts think that these attempts, and others like them, have more potential to harm the human race than to help it. Stephen Hawking voiced his concerns about responding to potential alien signals in the video “Stephen Hawking’s Favorite Places.” He pointed out that other civilizations could be “vastly more powerful and may not see us as any more valuable than we see bacteria.” After all, he argues, being friendly did not protect the Native Americans from European settlers.
Other experts, like Douglas Vakoch, argue that any alien advanced enough to be a threat to our world would have surely picked up on all the signals we’ve already vented into the universe. We haven’t been at all concerned about hiding our tracks to this point, so what good would ghosting extraterrestrials do us now?
How or whether we respond to alien life when we find it, one thing is certain — it will change our world forever. Sagan believed that the discovery could lead to a more humble and unified humanity. He reflected in Pale Blue Dot, “To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”
Trappist-1 is a Red Dwarf star — similar to our Sun — located about 40 light years from our system. Being a Red Dwarf, its lifetime is measured not in billions of years, but in trillions. As such, the Trappist System seemed like an ideal place to search for extraterrestrial life. However, like most Red Dwarf stars, Trappist-1 is prone to magnetic instability and huge flares.
A coronal mass injection caused by a solar flare
That’s what the team of researchers from Konkoly Observatory led by Krisztián Vida have discovered. They studied Trappist-1 photometric data collected by the Keppler-2 mission and found that Trappist-1’s flares may be too frequent and too intense for life to survive on the planets orbiting it. During an 80-day observation period, they manage to identify 42 strong flaring events — five were multi-peaked — at an average frequency of once every 28 hours.
Better Luck Next System
Flares are caused by stellar magnetism, which can make a star release sudden high energy bursts, usually in the range of X-ray or UV radiation. While our own solar system isn’t exempted from such flares, the Earth has largely been safe from these. One reason is our planet’s distance from the sun. Another is due to the magnetosphere — that region of space where the dominant magnetic field is the Earth’s and not that of interplanetary space — that surrounds our planet.
In the Trappist System, the researchers found that the flares are similar to the most powerful flare produced by our sun, known as the Carrington Event in 1859. It was so powerful that the impact on the Earth’s magnetosphere created auroras that stretched as far south as the Caribbean. At the same time, telegraph systems around the world were disturbed, and some telegraph operators even received electric shocks.
In the Trappist System, flares like this occur more frequently. With flares possibly hundreds or even thousands of times more powerful than what hits the Earth, the Trappist system does not seem that safe for life. “The flaring activity of TRAPPIST-1 probably continuously alters the atmospheres of the orbiting exoplanets, making these less favorable for hosting life,” the researchers wrote in the study’s abstract.
But those who search for extraterrestrial life need not worry. The Trappist System isn’t the only place where alien life might be found. Basic probability dictates that extraterrestrial life might just be hiding in the estimated 100 billion planets in the Milky Way alone. It just so happens that the seven rocky planets of the Trappist System might not be hosting any such life.
This past weekend, Neil deGrasse Tyson did a reddit AMA: “I am Neil deGrasse Tyson, your personal Astrophysicist.” Naturally, with this irresistible prompt, he got numerous responses, like this one: “Do you think we will ever make contact with complex organisms within the next 50 yrs?”
There are around 100 billion planets in the Milky Way galaxy alone. If even a tiny percentage of them are habitable (and they should be, even using conservative standards), that would still provide for alien life on millions of planets, and intelligent life on hundreds of thousands of those planets. Given these facts, the Fermi paradox asks: why do we appear to be alone?
Recent research from the Australian National University in 2016 suggested the reason we may not have found alien life is because any life that may have existed on other planets has died. Our survival on Earth, then, is largely down to a mix of planetary quirks and chance. Physicist Brian Cox thinks we won’t hear from intelligent aliens anytime soon (if ever) because life forms at that level tend to out-engineer themselves into extinction; destroying themselves by creating more technologies than they have the social and political expertise to manage (does that sound familiar?)
Cornell Astronomers appear to be on the same page as NdGT, arguing that due to the sheer amount of time it would take extraterrestrial life to receive our signals and respond, it could be around 1,500 years before we hear from any alien neighbors. At a panel on extraterrestrial life, NASA and SETI representatives pointed out that intelligent alien life may not even have a drive to explore and reach out. Or that if they do, they may have a policy similar to Star Trek’s Prime Directive, where they deliberately avoid making contact with other civilizations (namely, ours).
Stephen Hawking characterizes any first contact as dangerous, and points out that when Columbus came into contact with the populations native to the Americas, they were subject to a dominant culture that possessed superior technology and a world view that assessed them as inferior—something that could happen to us. Douglas Vakoch, the president of METI International, feels that any civilizations capable of interstellar travel would know about us already, so therefore they must not be hostile.
However, Tyson was responding to the question of our ability to strike out and discover life elsewhere, and his assessment is based on the challenges posed by traveling interstellar distances. It seems likely that if we progress in our abilities to travel through space faster than he’s predicting, he’ll be happy to have been proven wrong.
The extremely energetic events that we see out there in the Universe are usually caused by cataclysmic astrophysical events and activities of one sort or another. But what about Fast Radio Bursts? A pair of astrophysicists at Harvard say that the seldom seen phenomena could, maybe, possibly, be evidence of an advanced alien technology.
Fast radio bursts (FRBs) are short-lived radio pulses that last only a few milliseconds. It’s been assumed that they have some astrophysical cause. Fewer than 2 dozen of them have been detected since their discovery in 2007. They’re detected by our huge radio telescopes like the Arecibo Observatory in Puerto Rico, and the Parkes Observatory in Australia. They’re extremely energetic, and their source is a great distance from us.
The two astrophysicists, Avi Loeb at the Harvard-Smithsonian Center for Astrophysics, and Manasvi Lingam at Harvard University, decided to investigate the possibility that FRBs have an alien technological origin.
“Fast radio bursts are exceedingly bright given their short duration and origin at great distances, and we haven’t identified a possible natural source with any confidence. An artificial origin is worth contemplating and checking.” – Avi Loeb, Harvard-Smithsonian Center for Astrophysics
I’ll Take ‘Alien Signals’ For $200 Alex
Loeb and Lingam began by calculating how much energy would be needed to send a signal that strong across such an enormous distance. They found that doing so with solar energy requires a solar array with an area twice the surface area of Earth. That would be enough energy if the alien civilization was as close as we are to a star similar to our Sun.
Obviously, such a massive construction project is well beyond us. But however unlikely it sounds, it can’t be ruled out.
The pair also asked themselves questions about the viability of such a project. Would the heat and energy involved in such a solar array melt the structure itself? Their answer is that water-cooling would be sufficient to keep an array like this operating.
Their next question was, “Why build something like this in the first place?”
I’ll Take ‘Alien Spacecraft Propulsion Systems’ For $400 Alex”
The thinking behind their idea is based on an idea that we ourselves have had: Could we power a spacecraft by pushing on it with lasers? Or Microwaves? If we’ve thought of it, why wouldn’t other existing civilizations? If another civilization were doing it, what would the technology look like?
Their investigation shows that the engineering they’re talking about could power a spacecraft with a payload of a million tons. That would be about 20 times bigger than our largest cruise ship. According to Lingam, “That’s big enough to carry living passengers across interstellar or even intergalactic distances.”
If FRBs are indeed the result of an alien propulsion system, here’s how it would work: Earth is rotating and orbiting, which means the alien star and galaxy are moving relative to us. That’s why we would only see a brief flash. The beam sweeps across the sky and only hits us for a moment. The repeated appearance of the FRB could be a clue to its alien, technological origin.
The authors of the study outlining this thinking know that it’s speculative. But it’s their job to speculate within scientific constraints, which they have done. As they say in the conclusion of their paper, “Although the possibility that FRBs are produced by extragalactic civilizations is more speculative than an astrophysical origin, quantifying the requirements necessary for an artificial origin serves, at the very least, the important purpose of enabling astronomers to rule it out with future data.”
There are other interpretations when it comes to FRBs, of course. The others of another paper say that for at least one group of FRBs, known as FRB 121102, the source is likely astrophysical. According to them, FRBs likely come from “a young, highly magnetized, extragalactic neutron star.”
Lurking behind these papers are some intriguing questions that are also fun to ponder.
If the system required a solar array twice the size of Earth, where would the materials come from? If the system required water-cooling to avoid melting, where would all the water come from? It’s impossible to know, or to even begin speculating. But a civilization able to do something like this would have to be master engineers and resource exploiters. That goes without saying.
Why they might do it is another question. Probably the same reasons we would: curiosity and exploration, or maybe to escape a dying world.
Now, NASA has just made its plans to explore deeper into these ocean worlds official. Last month, NASA hosted the “Planetary Science Vision 2050 Workshop,” where proposals for exploring these ocean worlds were presented. Kevin Peter Hand, Deputy Chief Scientist for solar system exploration at NASA’s Jet Propulsion Laboratory (NASA-JPL), shared the findings of a report prepared by the 2016 Europa Lander Science Definition Team.
According to Hand, the purpose of exploring Europa’s oceans is threefold: First, it would search for biosignatures and signs of life by analyzing the surface and sub-surface materials of Europa. Then, it would involve in-situ analyses to determine the composition of non-ice, near-subsurface material. Lastly, it would be important to characterize Europa’s surface and subsurface properties, as well as the dynamic processes that shape them — all of which would be in support of further explorations.
Were biosignatures to be found in the surface material, direct access to, and exploration of, Europa’s ocean and liquid water environments would be a high priority goal for the astrobiological investigation of our solar system. Europa’s ocean would harbor the potential for the study of an extant ecosystem, likely representing a second, independent origin of life in our own solar system. Subsequent exploration would require robotic vehicles and instrumentation capable of accessing the habitable liquid water regions in Europa to enable the study of the ecosystem and organisms.
Targeting Ocean Worlds
The second presentation, by the Roadmaps to Ocean Worlds (ROW) team, took a more general approach. They classified ocean worlds as bodies “with a current liquid ocean (not necessarily global). All bodies in our solar system that plausibly can have or are known to have an ocean will be considered as part of this document.”
By this definition, the report included a number of possible targets for exploration: the aforementioned Europa, Ganymede, Callisto, Enceladus, as well as Triton, Pluto, Ceres, and Dione. They also mentioned Saturn’s moon Titan:
“Although Titan possesses a large subsurface ocean, it also has an abundant supply of a wide range of organic species and surface liquids, which are readily accessible and could harbor more exotic forms of life.”
The ROW Report outlined four goals: (1) to identify the ocean worlds in the solar system, (2) to characterize the nature of these oceans, (3) to determine if these could support and sustain life, and (4) to figure out how life could exist in them.
These plans outlined by NASA are going to be key in understanding our immediate neighborhood in space, as well as providing a more strategic approach to the search of extraterrestrial life.
“What we’ve found on Ceres is probably the most unambiguous detection of organics on any Solar System body other than Earth,” said Carlé Pieters, Dawn mission investigator, in an interview with Brown University. “We’ve collected meteorites on Earth with organic signatures, which makes us think their parent asteroids may have had organics. But until now we haven’t seen such definitive evidence on any asteroid. So this could help us put together the history of organics in the Solar System.”
“There are high-resolution data available from Dawn that provide the geologic context for these deposits,” added Pieters. “We’re looking at those data now, which will help us to pin down the origin of these materials.” The discovery was found in a crater-ridden region called Ernutet in the northern part of Ceres, and the team’s findings were published in the journal Science.
No E.T. Just Yet
Organic molecules, such as carbohydrates, nucleic acids, and proteins, are the basic building blocks of life. Organic materials have previously been found in meteorites and on Mars, and while finding these on Ceres doesn’t mean that there’s life on the dwarf planet, coupled with the discovery of water and carbonate minerals, they do indicate that Ceres is potentially ripe for life.
“It’s kind of like baking a cake,” Pieters explained. “You can have all the ingredients, but if you don’t put them together properly, you don’t end up with a cake. So there is still plenty of work to be done before we can start thinking about whether microbes were able to form on Ceres.”
While the discovery doesn’t directly translate to discovering extraterrestrial life, it definitely improves the chances of finding it. The fact that these ingredients of life are located in a single setting outside of Earth is a great first step.
Galilean moons. Recently, NASA has kickstarted plans to send a lander to the icy exoplanet in search of extraterrestrial life within its crust.
A 264-page report published by the space administration details their plans for the lander to drill approximately 4 inches (10 centimeters) into Europa’s crust and use its specially designed onboard instruments to test the moon’s chemical composition and capacity to breed organic life.
Despite information from past fly-bys, there’s still not much that we know about Europa. But with this alien mission, NASA hopes to, at the very least, improve our quality of understanding about the moon. They will release the lander into space by 2024, arriving on Europa by 2031.
Jonathan Lunine, an astronomer with NASA’s Science Definition Team (SDT), is hopeful about the mission. He states:
I was skeptical that we could in fact design a payload with a reasonable technological maturity and relative simplicity. Thanks to the engineers, a very practical solution was found and the payload we put together is not overly ambitious. The bottom line is, I became much more of a believer that this is a mission that can be done in a time frame I’d be interested, in the next 20 years or so.
Why Europa Could Contain Life
The lander’s onboard instruments will specifically be testing for biosignatures, which are signs of present or past life hidden within elements found on the moon. It will also assess the potential for the moon to become habitable in the future, and whether or not future missions could be successfully conducted.
NASA’s hope is that if there are future missions to Europa, a lander would be able to drill down far enough to reach the moon’s immense subterranean ocean, which is around 11.8 miles (19 km) below the surface.
But that’s not all that this mysterious moon touts. “Europa is provisionally a great place to go,” adds Lunine. “It has a very large amount of rocks, it’s got a lot of heat [at its core], so at the base of the oceans there are undoubtedly hydrothermal systems. Everything we know about it makes this a good [place] to look for life.”
About 14 light-years away from Earth, a small red dwarf star only a quarter the size of the Sun sheds a gloomy, crimson radiance on its little retinue of worlds—three planets, ranging from a smidge larger than Earth to over five times its size.
So far, so typical. But here’s where things get interesting: a nearer look discloses a few surprises about this little star and its miniature system. About a billion years younger than our Sun, the dwarf star is wracked by immense magnetic sunspots that blacken its ruddy face; from time to time it sends out arcing prominences and flares that scorch its closest child—a planet like Venus’ bigger, nastier brother, with a hellish atmosphere that precipitates liquid metals, and a surface convulsed by tidally-induced volcanism. Nothing lives in this nightmarish place.
Further out, a giant blue world—five times the size of Earth—plies a chilly orbit in the weird, dim glow of its scarlet primary; it’s like a mini-Neptune, its atmosphere of cold hydrocarbon smog concealing an immense world-ocean of hyper-pressurized H2O and exotic ices. Any life here would be rudimentary—at best.
But between these two extremes swings a little planet only slightly larger than Earth; its atmosphere is dense but clear, its surface largely drowned in a rust-red, shallow ocean constellated with island chains and microcontinents. A closer examination shows that these tiny landmasses, and the shallow coastal seas surrounding them, are dotted with curious “forests” of black, plant-like things swaying gently in the wind; not plants at all, they’re really a kind of commensal pseudo-bacteria that grow in great colonies like the stromatolites of early Earth. Their broad, black leaf-like surfaces absorb and metabolize their sun’s plentiful infrared light, while their metabolic wastes filter down to be consumed by the non-phototrophic organisms at the base of the colony.
These biomes have lived for only a few days. In a few more, the planet’s nearness to its sun will be unbearable; all the colonies will die off, leaving behind dormant spores to grow again in the brief fall. A glacial period of bitter cold and spreading ice will follow, gripping the planet for a few days and unleashing a ferocious “ice age” ere the return of spring. This is just one year in the life of the planet—a year spanning a mere 17 terrestrial days.
Meanwhile, this swift drama of life and death and changing seasons accelerates the pace of evolution beyond anything experienced on Earth; the planet has been habitable for less than half a billion years. Give it another half billion…who knows what might evolve?
A Nice Place to Live?
The planet is called Wolf 1061c, and it belongs to one of the nearest planetary systems to the Earth. The above scenario is a fantasy—but it’s an informed and plausible fantasy, founded on the knowledge we have that Wolf 1061c orbits within the habitable zone (HZ) of its red dwarf sun. And as our technology becomes more sophisticated, and our understanding of exoplanets grows, we may someday learn whether such scenarios are really possible.
Deciphering the parameters of extrasolar HZs is proving to be more difficult than expected; there’s a lot to juggle, and, with only one example before us, we’re not exactly in a position to speak authoritatively on the subject. One important point to keep in mind is that a star’s HZ changes in time as well as space; as a star ages, and grows hotter, its HZ sweeps further outward, desolating formerly habitable worlds and making a paradise of formerly uninhabitable ones.
So there are many variables that can skew any assessment of a distant star’s potential to host habitable planets: the mass, composition, and geology of a planet. The size, temperature, and age of a star; the presence of any companion suns; the eccentricity of a planet’s orbit; proximity to the galactic core, and others too numerous to list.
About the best astronomers can do is try to gather as much information as they can through their imperfect telescopes, and extrapolate from there about a system’s life-sustaining potential. For instance, Kane’s team at SFSU—together with collaborators from Tennessee State University and Geneva, Switzerland—was able to determine that Wolf 1061c orbits a little too close to the inner edge of the star’s HZ, but that its swift orbital changes could keep the planet’s conditions from reaching Venus-like extremes.
“The Wolf 1061 system is important because it is so close and that gives other opportunities to do follow-up studies to see if it does indeed have life.” —Stephen Kane, SFSU
That’s a start, and we’ll do better in the future. The James Webb Space Telescope, Hubble’s successor, is slated to launch next year; it will have the requisite resolving power to disentangle the atmospheric composition of distant worlds like Wolf 1061c, and possibly even detect the traces of biogenic chemistry.
And there are other future space telescope architectures on the drawing board—missions like TESS (Transiting Exoplanet Survey Satellite) and the projected ATLAST space telescope. These, we hope, will pinpoint transits, image planets directly, and study atmospheric spectra with greater precision—all of which will help us calibrate our understanding of habitable conditions around alien stars.
In the meantime, we’ll continue to scan the skies and explore the planets of alien solar systems with our increasingly more powerful instruments. We’ll compile a list of stars that are the most likely to host life-bearing planets, and someday, perhaps, we’ll finally spot a distant world—whether Wolf 1061c or someplace yet undiscovered—that discloses the first thrilling biosignatures in its atmospheric spectrum.
The researchers studied isotopic traces of the element selenium in sedimentary rocks as a tool to measure oxygen levels in the Earth’s atmosphere some 2 to 2.4 billion years ago. They analyzed these selenium traces in sedimentary shale pieces using mass spectrometry in the UW Isotope Geochemistry Lab. They checked if selenium was oxidized or changed by the presence of oxygen. If so, oxidized selenium compounds could have been reduced, causing isotopic ratio shifts that would be recorded on the rocks. When oxygen is present, selenium in rocks also becomes abundant.
“There is fossil evidence of complex cells that go back maybe 1 ¾ billion years, but the oldest fossil is not necessarily the oldest one that ever lived – because the chances of getting preserved as a fossil are pretty low,” said researcher Roger Buick. “This research shows that there was enough oxygen in the environment to have allowed complex cells to have evolved, and to have become ecologically important, before there was fossil evidence. That doesn’t mean that they did — but they could have.”
Previously, the general thought was that oxygen appeared on Earth and gradually increased to the point where complex life could exist. “But what it looks like now is, there was a period of a quarter of a billion years or so where oxygen came quite high, and then sunk back down again,” Buick explained. This duration is important. “Whereas before and after maybe there were transient environments that could have occasionally supported these organisms, to get them to evolve and be a substantial part of the ecosystem, you need oxygen to persist for a long time,” said lead author Michael Kipp.
Based on this evidence of an oxygen overshoot on our own planet, it would appear that the conditions that make complex life possible aren’t a rare phenomena that can only happen once in 4.5 billion years, and each occurrence can last for a significant duration of time. If this is true, what was this life on Earth like? Did some of it evolve, and if so, into what?
To be sure of anything, though, we’d need to find some evidence of this earlier life, if there is any. Aside from that, the question of what caused oxygen levels to go up so high and then disappear dramatically, only to reappear again about one billion years later, remains. “That’s the million-dollar question,” researcher Eva Stüeken said. “It’s unknown why it happened, and why it ended.”
Furthermore, could the same thing have happened on Earth-like exoplanets? The method used by the UW researchers could be replicated in the future to check if the same conditions that made life possible in Earth’s past ever existed on other planets. Ultimately, this research could simultaneously change the way we look for extraterrestrial life and how we think about past life on our home planet.
For the greater part of 2016, Mars was the focus of mankind’s fascination with space, and so much of this focus centered on our desire to know about life on the Red Planet. Was Mars once a host to extraterrestrial life? Well, NASA’s Curiosity rover has been on a mission to satisfy this curiosity, and recently, it uncovered something worthwhile to add to its discovery notes from last year.
Scientists are convinced, more than ever, that Mars was once a wet planet. Some billions of years ago, Mars hosted large lakes, they assert, and traces of evidence supporting this assertion have been discovered by Curiosity. The rover has also found mineral deposits that suggest the previous periods with water lasted even longer than we thought.
For the past several weeks, the Martian rover has been examining slabs of rock cross-hatched with shallow ridges in an area of Mars known as “Old Soaker.” NASA believes that these could be mud cracks that formed about 3 billion years ago. “Mud cracks are the most likely scenario here,” said Nathan Stein, a member of Curiosity’s team. “It looks like what you’d see beside the road where muddy ground has dried and cracked,” he added.
So, Mars most probably had water, but does this mean that there was some kind of life on the Red Planet? Everywhere we find liquid water on Earth, we find life, but Curiosity will need to roam around a little more before we can be sure that the same can be said of Mars.
In short, Schneider has a keen understanding of the intersection between science and philosophy. As such, she also has a unique perspective on AI, offering a fresh (but quite alarming) view on how artificial intelligence could forever alter humanity’s existence. In an article published by the IEET, she shares that perspective, talking about potential flaws in the way we view AI and suggesting a possible connection between AI and extraterrestrial life.
The bridge Schneider uses to make this connection is the idea of a “postbiological” life. In the article she explains that postbiological refers to either the eventual form of existence humanity will take or the AI-emergent lifeforms that would replace our existence altogether. In other words, it could be something like superintelligent humans enhanced through biological nanotechnology or it could be an artificially intelligent supercomputer.
Whatever form postbiological life takes, Schneider posits that the transition we’re currently experiencing is one that may have happened previously on other planets:
The technological developments we are witnessing today may have all happened before, elsewhere in the universe. The transition from biological to synthetic intelligence may be a general pattern, instantiated over and over, throughout the cosmos. The universe’s greatest intelligences may be postbiological, having grown out of civilizations that were once biological.
In light of that, Schneider asks the following: “Suppose that intelligent life out there is postbiological. What should we make of this?”
Extraterrestrial, Postbiological AI
There isn’t any guarantee that we can “control” AI on Earth when it becomes superintelligent, even with multi-million-dollar efforts devoted to AI safety. “Some of the finest minds in computer science are working on this problem,” Schneider writes. “They will hopefully create safe systems, but many worry that the control problem is insurmountable.”
If artificially intelligent postbiological life exists elsewhere in our universe, it’s a major cause of concern for a number of reasons. “[Postbiological extraterrestrial life] may have goals that conflict with those of biological life, have at its disposal vastly superior intellectual abilities, and be far more durable than biological life,” Schneider argues. These lifeforms also might not place the same value on biological intelligence that we do, and they may not even be conscious in the same manner that we are.
Schneider makes the comparison between how we feel killing a chimp versus eating an apple. Both are technically living organisms, but because we have consciousness, we place a higher value on other species that have it as well. If superintelligent, postbiological extraterrestrials don’t have consciousness, can we expect them to understand us? Even more importantly, would they value us at all? Food for thought for any proponents of active SETI.
A team of geoscientists from the University of Toronto has discovered water 3 km (~1.9 miles) deep in a mine in Timmins, Ontario, Canada.
And it’s really, really old—about 2 billion years old, to be precise. “Everything about the water is brand new. We are seeing signals in all isotopes that we’ve identified so far that we’ve never seen anywhere else,” says postdoctoral researcher Oliver Warr. The team’s findings were recently presented at the American Geophysical Union in San Fransisco.
In order to date water, researchers have to look at the accumulation of gases in the sample. This particular bucketful of ancient water contained helium, argon, neon, krypton and xenon. Calculating how much of these elements accumulated over the immense gulfs of time that this water has existed helped researchers identify its age.
The water has been described as being 8 times saltier than sea water. “It won’t kill you if you drank it, but it would taste absolutely disgusting.”
Water With a Story to Tell
Much can be learned from such a discovery. According to Warr, “If water has been down there for up to two billion years, it can tell us something about the atmosphere at the time, or the state of the Earth, which previously we’ve not been able to get much insight into.” And not only can we learn about the conditions in which the water may have existed billions of years ago, but there’s also a chance it may actually contain ancient life
“That could have great ramifications as to how life might exist at these kinds of depths, how it might survive,” Warr said. “It could start paving the way for understanding life on other planets as well.” Earlier this year, scientists discovered 3.7 billion year old fossils in Greenland, which would make it entirely possible for this 2 billion-year-old water to contain traces of life, if not entire organisms.
The extreme conditions for billions of years ago could give some important insight into how life began on our planet, or even how it might exist on the harsh conditions of planets like Mars.
A recent discovery supports these claims. The Curiosity rover’s study of different rocks over the Gale Crater’s elevational range of about 200 meters (650 ft) covers a timespan of roughly tens of millions to hundreds of millions of years. Throughout this period, the environment in the crater, which supposedly cradled an ancient Martian lake, was continually changing, but not enough to preclude life from existing.
The newest evidence of this ancient life on Mars is Curiosity’s discovery of boron, marking the first time that this element has been found on the Red Planet.
“We are seeing chemical complexity indicating a long, interactive history with the water. The more complicated the chemistry is, the better it is for habitability,” John Grotzinger, Curiosity team member and geologist at the California Institute of Technology in Pasadena, explained in a press release. “The boron, hematite, and clay minerals underline the mobility of elements and electrons, and that is good for life.”
Where There Is Water…
Based on observations by Curiosity, the ancient lake in the Gale Crater was initially composed of fresh water (neutral-pH water). It became slightly acidic over time, and saltier still a little later.
This all happened over a period of millions of years, as the crater’s lake went through periods of drying out and then filling up again as groundwater rose. Despite these changes, Grotzinger believes that the area remained mostly habitable, as some forms of microbial life could’ve been sustained by groundwater during the lake’s dry spells.
If the conditions on ancient Mars were largely similar to those on Earth, where there is water, there is a great chance that life could exist, as well. The abundant traces of silica, which is excellent at preserving microbial life on Earth, found in Curiosity’s samples could aid future life-hunting missions on Mars. “I think this is a tremendously exciting discovery,” said Grotzinger.
While light helps us see things better here on Earth, it can actually pose a challenge for practitioners of astronomy whose views of celestial bodies can be obstructed by background light from nearby stars. Now, scientists from the Australian National University have found a way to address the problem.
The ANU researchers have created a new optical chip for telescopes that can negate the light from the closest star to a planet. The new chip works similarly to noise-canceling headphones. “This chip is an interferometer that adds equal but opposite light waves from a host sun, which cancels out the light from the sun, allowing the much weaker planet light to be seen,” explains Associate Professor Steve Madden from the ANU.
The Search for Life
Previously, astronomers could make an educated guess as to which planets could contain life by determining if they were in the habitable zone of a star or not. This method has given us a whole slew of possibly habitable planets outside of our solar system. However, Lucianne Walkowicz from Princeton University says that location is just one variable with regards to habitability and that the presence of radioactive flares from a star could affect the habitability of a planet as well.
Not only would this new optical chip give us a better look at other planets in general, it could also be used to determine if a planet is protected from star flares by ozone, thus giving it a higher possibility of harboring life. “The chip uses the heat emitted from the planet to peer through dust clouds and see planets forming,” says Kenchington Goldsmith from the ANU Research School of Physics and Engineering. “Ultimately the same technology will allow us to detect ozone on alien planets that could support life.”
In the hunt for a celestial body that could host life (specifically, life like that found on Earth), scientists have typically looked for planets with surfaces similar to our own — about the same temperature, same chemical makeup, and, ideally, with liquid water like that from which we evolved. Now, a whole new group of space objects has joined the list of potential life-supporting hosts, and they don’t have a planet-like surface at all.
Researchers from the University of Edinburgh in the United Kingdom have proposed that we look for life in the upper atmospheres of cold brown dwarfs. These “failed stars” have the same elements found in traditional stars, but they lack the mass to ignite. Somewhere between the size of a planet and a star, they can boast atmospheres that hover around temperatures that would be considered comfortable on Earth and with about the same pressure levels.
“You don’t necessarily need to have a terrestrial planet with a surface,” Jack Yates, a planetary scientist who led the study, told Science.
The Hunt Is On
This development would open up a whole new arena in the hunt for extraterrestrial life, just maybe not life that looks like we do.
Microbes like those that lurk high above our own atmosphere could be discovered, or perhaps we’d find some of the sky plankton Carl Sagan coined “sinkers.” “Floaters,” organisms that manipulate their body pressure to rise and fall within an atmosphere, could also be hovering above cold brown dwarfs.
Though we only know of a handful of cold brown dwarfs right now, about 10 of those are likely to be within 30 light-years of Earth. With the James Webb Space Telescope (JWST) set to launch in just over a year, we may have our answer as to whether these bodies host life sooner rather than later.
Not only would it be a huge discovery if they do, it would also throw out the window our preconceived notions about where to look for life beyond our planet.