People are always worried that alien civilizations will detect the transmissions from our old radio shows and television broadcasts, and send in the invasion fleet. But the reality is that life itself has been broadcasting the existence of life on Earth for 500 million years.Continue reading “Searching For The Red Edge: How The Earth’s Forests Are Telling The Aliens Where We Live”
The METI Symposium
How could you devise a message for intelligent creatures from another planet? They wouldn’t know any human language. Their ‘speech’ might be as different from ours as the eerie cries of whales or the twinkling lights of fireflies. Their cultural and scientific history would have followed its own path. Their minds might not even work like ours. Would the deep structure of language, its so called ‘universal grammar’ be the same for aliens as for us? A group of linguists and other scientists gathered on May 26 to discuss the challenging problems posed by devising a message that extraterrestrial beings could understand. There are growing hopes that such beings might be out there among the billions of habitable planets that we now think exist in our galaxy. The symposium, called ‘Language in the Cosmos’ was organized by METI International. It took place as part of the National Space Society’s International Space Development Conference in Los Angeles. The Chair of the workshop was Dr. Sheri Wells-Jensen, a linguist from Bowling Green State University in Ohio.
What is METI International?
‘METI’ stands for messaging to extraterrestrial intelligence. METI International is an organization of scientists and scholars that aims to foster an entirely new approach in our search for alien civilizations. Since 1960, researchers have been looking for extraterrestrials by searching for possible messages they might send to us by radio or laser beams. They have sought the giant megastructures that advanced alien societies might build in space. METI International wants to move beyond this purely passive search strategy. They want to construct and transmit messages to the planets of relatively nearby stars, hoping for a response.
One of the organization’s central goals is to build an interdisciplinary community of scholars concerned with designing interstellar messages that can be understood by non-human minds. More generally, it works internationally to promote research in the search for extraterrestrial intelligence and astrobiology, and to understand the evolution of intelligence here on Earth. The daylong symposium featured eleven presentations. It main theme was the role of linguistics in communication with extraterrestrial intelligence.
This article is the first in a two part series. It will focus on one of the most fundamental issues addressed at the conference. This is the question of whether the deep underlying structure of language would likely be the same for extraterrestrials as for us. Linguists understand the deep structure of language using the theory of ‘universal grammar’. The eminent Linguist Noam Chomsky developed this theory in the middle of the twentieth century.
Two interrelated presentations at the symposium addressed the issue of universal grammar. The first was by Dr. Jeffery Punske of Southern Illinois University and Dr. Bridget Samuels of the University of Southern California. The second was given by Dr. Jeffrey Watumull of Oceanit, whose coauthors were Dr. Ian Roberts of the University of Cambridge, and Dr. Noam Chomsky himself, of the Massachusetts Institute of Technology.
Chomsky’s universal grammar-For humans only?
Despite its name, Chomsky originally took his ‘universal grammar’ theory to imply that there are major, and maybe insuperable barriers to mutual understanding between humans and extraterrestrials. Let’s first consider why Chomsky’s theories seemed to make interstellar communication virtually hopeless. Then we’ll examine why Chomsky’s colleagues who presented at the symposium, and Chomsky himself, now think differently.
Before the second half of the twentieth century, linguists believed that the human mind was a blank slate, and that we learned language entirely by experience. These beliefs dated to the seventeenth century philosopher John Locke and were elaborated in the laboratories of behaviorist psychologists in the early twentieth century. Beginning in the 1950’s, Noam Chomsky challenged this view. He argued that learning a language couldn’t simply be a matter of learning to associate stimuli with responses. He saw that young children, even before the age of 5, can consistently produce and interpret original sentences that they had never heard before. He spoke of a “poverty of the stimulus”. Children couldn’t possibly be exposed to enough examples to learn the rules of language from scratch.
Chomsky posited instead that the human brain contained a “language organ”. This language organ was already pre-organized at birth for the basic rules of language, which he called “universal grammar”. It made human infants primed and ready to learn whatever language they were exposed to using only a limited number of examples. He proposed that the language organ arose in human evolution, maybe as recently of 50,000 years ago. Chomsky’s powerful arguments were accepted by other linguists. He came to be regarded as one of the great linguists and cognitive scientists of the twentieth century.
Universal grammar and ‘Martians’
Human beings speak more than 6000 different languages. Chomsky defined his “universal grammar” as “the system of principles, conditions, and rules that are elements or properties of all human languages”. He said it could be taken to express “the essence of human language”. But he wasn’t convinced that this ‘essence of human language’ was the essence of all theoretically possible languages. When Chomsky was asked by an interviewer from Omni Magazine in 1983 whether he thought that it would be possible for humans to learn an alien language, he replied:
“Not if their language violated the principles of our universal grammar, which, given the myriad ways that languages can be organized, strikes me as highly likely…The same structures that make it possible to learn a human language make it impossible for us to learn a language that violates the principles of universal grammar. If a Martian landed from outer space and spoke a language that violated universal grammar, we simply would not be able to learn that language the way that we learn a human language like English or Swahili. We should have to approach the alien’s language slowly and laboriously — the way that scientists study physics, where it takes generation after generation of labor to gain new understanding and to make significant progress. We’re designed by nature for English, Chinese, and every other possible human language. But we’re not designed to learn perfectly usable languages that violate universal grammar. These languages would simply not be within the range of our abilities.”
If intelligent, language-using life exists on another planet, Chomsky knew, it would necessarily have arisen by a different series of evolutionary changes than the uniquely improbable path that produced human beings. A different history of climate changes, geological events, asteroid and comet impacts, random genetic mutations, and other events would have produced a different set of life forms. These would have interacted with one another in a different ways over the history of life on the planet. The “Martian” language organ, with its different and unique history, could, Chomsky surmised, be entirely different from its human counterpart, making communication monumentally difficult, if not impossible.
Convergent evolution and alien minds
The tree of life
Why did Chomsky think that the human and ‘Martian‘ language organ would likely be fundamentally different? How come he and his colleagues now hold different views? To find out, we first need to explore some basic principles of evolutionary theory.
Originally formulated by the naturalist Charles Darwin in the nineteenth century, the theory of evolution is the central principle of modern biology. It is our best tool for predicting what life might be like on other planets. The theory maintains that living species evolved from previous species. It asserts that all life on Earth is descended from an initial Earthly life form that lived more than 3.8 billion years ago.
You can think of these relationships as like a tree with many branches. The base of the trunk of the tree represents the first life on Earth 3.8 billion years ago. The tip of each branch represents now, and a modern species. The diverging branches connecting each branch tip with the trunk represent the evolutionary history of each species. Each branch point in the tree is where two species diverged from a common ancestor.
Evolution, brains, and contingency
To understand Chomsky’s thinking, we’ll start with a familiar group of animals; the vertebrates, or animals with backbones. This group includes fishes, amphibians, reptiles, birds, and mammals, including humans.
We’ll compare the vertebrates with a less familiar, and distantly related group; the cephalopod molluscs. This group includes octopuses, squids, and cuttlefish. These two groups have been evolving along separate evolutionary paths-different branches of our tree-for more than 600 million years. I’ve chosen them because, as they’ve traveled along their separate branch of our evolutionary tree, each has evolved it own sort of complex brains and complex sense organs.
The brains of all vertebrates have the same basic plan. This is because they all evolved from a common ancestor that already had a brain with that basic plan. The octopus’s brain, by contrast, has an utterly different organization. This is because the common ancestor of cephalopods and vertebrates lies much further back in evolutionary time, on a lower branch of our tree. It probably had only the simplest of brains, if any at all.
With no common plan to inherit, the two kinds of brains evolved independently of one another. They are different because evolutionary change is contingent. That is, it involves varying combinations of influences, including chance. Those contingent influences were different along the path that produced cephalopod brains, than along the one that led to vertebrate brains.
Chomsky believed that many languages might be theoretically possible that violated the seemingly arbitrary constraints of human universal grammar. There didn’t seem to be anything that made our actual universal grammar something special. So, because of the contingent nature of evolution, Chomsky assumed that the ‘Martian’ language organ would arrive at one of these other possibilities, making it fundamentally different from its human counterpart.
This sort of evolution-based pessimism about the likelihood that humans and aliens could communicate is widespread. At the symposium, Dr. Gonzalo Munévar of Lawrence Technological University argued that intelligent creatures that evolved sensory systems and cognitive structures different from ours would not develop similar scientific theories or even similar mathematics.
Evolution, eyes, and convergence
Now lets consider another feature of the octopus and other cephalopods; their eyes. Surprisingly, the eyes of octopuses resemble those of vertebrates in intricate detail. This uncanny resemblance can’t be explained in the same way as the general resemblance of vertebrate brains to one another. It’s almost certainly not due to inheritance of the traits from a common ancestor. It’s true that some of the genes involved in the building of eyes are the same in most animals, appearing far down towards the trunk of our evolutionary tree. But, biologists are almost certain that the common ancestor of cephalopods and vertebrates was much too simple to have any eyes at all.
Biologists think eyes evolved separately more than forty times on Earth, each on its own branch of the evolutionary tree. There are many different kinds of eyes. Some are so strangely different from our own that even a science fiction writer would be surprised by them. So, if evolutionary change is contingent, why do octopus eyes bear a striking and detailed similarity to our own? The answer lies outside of evolutionary theory, with the laws of optics. Many large animals, like the octopus, need acute vision. There is only one good way, under the laws of optics, to make an eye that meets the needed requirements. Whenever such an eye is needed, evolution finds this same best solution. This phenomenon is called convergent evolution.
Life on another planet would have its own separate evolutionary tree, with the base of the trunk representing the appearance of life on that planet. Because of the contingency of evolutionary change, the pattern of branches might be quite different from our Earthly evolutionary tree. But because the laws of optics are the same everywhere in the universe, we can expect that large animals under similar conditions will evolve an eye that looks a lot like that of a vertebrate or a cephalopod. Convergent evolution is potentially a universal phenomenon.
Not just for humans anymore?
Taking apart the language organ
By the beginning of the twenty-first century, Chomsky and some of his colleagues started to look at the language organ and universal grammar in a new way. This new view made it seem like the properties of universal grammar were inevitable, much as the laws of optics made many features of the octopus’s eye inevitable.
In a 2002 review, Chomsky and his colleagues Marc Hauser and Tecumseh Fitch argued that the language organ can be decomposed into a number of distinct parts. The sensory-motor, or externalization, system is involved in the mechanics of expressing language through methods like vocal speech, writing, typing, or sign language. The conceptual-intentional system relates language to concepts.
The core of the system, the trio proposed, consists of what they called the narrow faculty of language. It is a system for applying the rules of language recursively, over and over, thereby allowing the construction of an almost endless range of meaningful utterances. Jeffrey Punske and Bridget Samuels similarly spoke of a ‘syntactic spine’ of all human languages. Syntax is the set of rules that govern the grammatical structure of sentences.
The inevitability of universal grammar
Chomsky and his colleagues made a careful analysis of what computations a nervous system might need to perform in order to make this recursion possible. As an abstract description of how the narrow faculty works, the researchers turned to a mathematical model called the Turing machine. The mathematician Alan Turing developed this model early in the twentieth century. This theoretical ‘machine’ led to the development of electronic computers.
Their analysis led to a striking and unexpected conclusion. In a book chapter currently in press, Watumull and Chomsky write that “Recent work demonstrating the simplicity and optimality of language increases the cogency of a conjecture that at one time would have been summarily dismissed as absurd: the basic principles of language are drawn from the domain of (virtual) conceptual necessity”. Jeffrey Watumull wrote that this strong minimalist thesis posits that “there exist constraints in the structure of the universe itself such that systems cannot but conform”. Our universal grammar is something special, and not just one among many theoretical possibilities.
Plato and the strong minimalist thesis
The constraints of mathematical and computational necessity shape the narrow faculty to be as it is, just like the laws of optics shape both the vertebrate and the octopus eye. ‘Martian’ languages, then, might follow the same universal grammar as human languages because there is only one best way to make the recursive core of the language organ.
Through the process of convergent evolution, nature would be compelled to find this one best way wherever and whenever in the universe that language evolves. Watumull supposed that the brain mechanisms of arithmetic might reflect a similarly inevitable convergence. That would mean that the basics of arithmetic would also be the same for humans and aliens. We must, Watumull and Chomsky wrote “rethink any presumptions that extraterrestrial intelligence or artificial intelligence would really be all that different from human intelligence”.
This is the striking conclusion that Watumull, and in a complementary way, Punske and Samuels presented at the symposium. Universal grammar may actually be universal, after all. Watumull compared this thesis to a modern, computer age version of the beliefs of the ancient Greek philosopher Plato, who maintained that mathematical and logical relationships are real things that exist in the world apart from us, and are merely discovered by the human mind. As a novel contribution to a difficult ages-old philosophical problem, these new ideas are sure to stir controversy. They illustrate the depth of new knowledge that awaits us as we reach out to other worlds and other minds.
Universal grammar and messages for aliens
What are the consequences of this new way of thinking about the structure of language for practical attempts to create interstellar messages? Watumull thinks the new thinking is a challenge to “the pessimistic relativism of those who think it overwhelmingly likely that terrestrial (i.e. human) intelligence and extraterrestrial intelligence would be (perhaps in principle) mutually unintelligible”. Punske and Samuels agree, and think that “math and physics likely represent the best bet for common concepts that could be used as a starting point”.
Watumull supposes that while the minds of aliens or artificial intelligences may be qualitatively similar to ours, they may differ quantitatively in having bigger memories, or the ability to think much faster than us. He is confident that an alien language would likely include nouns, verbs, and clauses. That means they could probably understand an artificial message containing such things. Such a message, he thinks, might also profitably include the structure and syntax of natural human languages, because this would likely be shared by alien languages.
Punske and Samuels seem more cautious. They note that “There are some linguists who don’t believe nouns and verbs are universal human language categories”. Still, they suspect that “alien languages would be built of discrete meaningful units that can combine into larger meaningful units”. Human speech consists of a linear sequence of words, but, Punske and Samuels note that “Some of the linearity imposed on human language may be due to the constraints of our vocal anatomy, and already starts to break down when we think about signed languages”.
Overall, the findings foster new hope that devising a message comprehensible to extraterrestrials is feasible. In the next installment, we will look at a new example of such a message. It was transmitted in 2017 towards a star 12 light years from our sun.
References and further reading
Allman J. (2000) Evolving Brains, Scientific American Library
Chomsky, N. (2017) The language capacity: Architecture and evolution, Psychonomics Bulletin Review, 24:200-203.
Gliedman J. (1983) Things no amount of learning can teach, Omni Magazine, chomsky.info
Hauser, M. D. , Chomsky, N. , and Fitch W. T. (2002) The faculty of language: What is it, Who has it, and How did it evolve? Science, 298: 1569-1579.
Land, M. F. and Nilsson, D-E. (2002) Animal Eyes, Oxford Animal Biology Series
Noam Chomsky’s theories on language, Study.com
Patton P. E. (2014) Communicating across the cosmos. Part 1: Shouting into the darkness, Part 2: Petabytes from the stars, Part 3: Bridging the vast gulf, Part 4: Quest for a Rosetta Stone, Universe Today.
Patton P. E. (2016) Alien Minds, I. Are extraterrestrial civilizations likely to evolve, II. Do aliens think big brains are sexy too?, III. The octopus’s garden and the country of the blind, Universe Today
Since the Universe is big and old, and life on Earth didn’t take relatively long to evolve, then life should be everywhere in the Universe. And yet, no matter how hard we look, we don’t see any evidence of it out there, not on Mars, not sending us radio messages, and not taking over entire galaxies and using up all their energy.
This, of course, is the Fermi Paradox, and it’s an absolutely fascinating concept to think about. There are many possible resolutions to the Fermi Paradox, but most of them are unsatisfying. Sure, we could be living in a cosmic zoo, or we fundamentally misunderstand how difficult it’ll be to travel to another star.
And maybe we’re just the first lifeforms in the observable Universe that have reached the level of technology that can conceive of exploring the Universe. But then, what are the chances of that? That really seems unlikely.
But then there’s the idea of the Great Filter. That there’s some kind of event that affects every single intelligent civilization, stopping it from reaching out into the galaxy, sending out signals, and exploring other worlds. Something wipes them out every time.
And considering the fact that we’re on the verge of becoming a multi-planet species ourselves, this concept of the Great Filter becomes even more unsettling.
It could be right around the corner from us.
Our friends at Kurzgesagt just released a video all about the Great Filter, and honestly, I think it’s the best video they’ve ever done. The animation, as always, is excellent, but the way they approach the Great Filter is really innovative, showing how evidence of life in the Universe is actually a bad sign, since it means we’re probably not the first life forms out there.
Which means the Great Filter is even more likely.
If you want to support what Kurzgesagt is doing, join their Patreon program and help them make even more videos.
The supertelescopes are coming, enormous ground and space-based observatories that’ll let us directly observe the atmospheres of distant worlds. We know there’s life on Earth, and our atmosphere tells the tale, so can we do the same thing with extrasolar planets? It turns out, coming up with a single biosignature, a chemical in the atmosphere that tells you that yes, absolutely, there’s life on that world, is really tough.
I’ve got to admit, I’ve been pretty bad for this in the past. In old episodes of Astronomy Cast and the Weekly Space Hangout, even here in the Guide to Space, I’ve said that if we could just sample the atmosphere of a distant world, we could say with conviction if there’s life there.
Just detect ozone in the atmosphere, or methane, or even pollution and you could say, “there’s life there.” Well, future Fraser is here to correct past Fraser. While I admire his naive enthusiasm for the search for aliens, it turns out, as always, things are going to be more difficult than we previously thought.
Astrobiologists are actually struggling to figure out a single smoking gun biosignature that could be used to say there’s life out there. And that’s because natural processes seem to have clever ways of fooling us.
What are some potential biosignatures, why are they problematic, and what will it take to get that confirmation?
Let’s start with a world close to home: Mars.
For almost two decades, astronomers have detected large clouds of methane in the atmosphere of Mars. Here on Earth, methane comes from living creatures, like bacteria and farting cows. Furthermore, methane is easily broken down by sunlight, which means that this isn’t ancient methane leftover from billions of years ago. Some process on Mars is constant replenishing it.
Well, in addition to life, methane can form naturally through volcanism, when rocks interact with heated water.
NASA tried to get to the bottom of this question with the Spirit and Opportunity rovers, and it was expected that Curiosity should have the tools on board to find the source of the methane.
Over the course of several months, Curiosity did detect a boost of methane down there on the surface, but even that has led to a controversy. It turns out the rover itself was carrying methane, and could have contaminated the area around itself. Perhaps the methane it detected came from itself. It’s also possible that a rocky meteorite fell nearby and released some gas that contaminated the results.
The European Space Agency’s ExoMars mission arrived at Mars in October, 2016. Although the Schiaparelli Lander was destroyed, the Trace Gas Orbiter survived the journey and began mapping the atmosphere of Mars in great detail, searching for places that could be venting methane, and so far, we don’t have conclusive results.
In other words, we’ve got a fleet of orbiters and landers at Mars, equipped with instruments designed to sniff out the faintest whiff of methane on Mars.
There’s some really intriguing hints about how the methane levels on Mars seem to rise and fall with the seasons, indicating life, but astrobiologists still don’t agree.
Extraordinary claims require extraordinary evidence and all that.
Some telescopes can already measure the atmospheres of planets orbiting other stars. For the last decade, NASA’s Spitzer Space Telescope has been mapping out the atmospheres of various worlds. For example, here’s a map of the hot jupiter HD 189733b. The place sucks, but wow, to measure an atmosphere, of another planet, that’s pretty spectacular.
They perform this feat by measuring the chemicals of the star while the planet is passing in front of it, and then measure it when there’s no planet. That tells you what chemicals the planet is bringing to the party.
They also were able to measure the atmosphere of HAT-P-26b, which is a relatively small Neptune-sized world orbiting a nearby star, and were surprised to find water vapor in the atmosphere of the planet.
Does that mean there’s life? Wherever we find water on Earth we find life. Nope, you can totally get water without having life.
When it launches in 2019, NASA’s James Webb Space Telescope is going to take this atmospheric sensing to the next level, allowing astronomers to study the atmospheres of many more worlds with a much higher resolution.
One of the first targets for Webb will be the TRAPPIST-1 system with its half-dozen planets orbiting in the habitable zone of a red dwarf star. Webb should be able to detect ozone, methane, and other potential biosignatures for life.
So what will it take to be able to view a distant world and know for sure there’s life there.
Astrobiologist John Lee Grenfell from the German Aerospace Centre recently created a report, going through all the exoplanetary biosignatures that could be out there, and reviewed them for how likely they were to be an indication of life on another world.
The first target will be molecular oxygen, or O2. You’re breathing it right now. Well, 21% of every breath, anyway. Oxygen will last in the atmosphere of another world for thousands of years without a source.
It’s produced here on Earth by photosynthesis, but if a world is being battered by its star, and losing atmosphere, then the hydrogen is blown off into space, and molecular oxygen can remain. In other words, you can’t be certain either way.
How about ozone, aka O3? O2 is converted into O3 through a chemical process in the atmosphere. It sounds like a good candidate, but the problem is that there are natural processes that can produce ozone too. There’s an ozone layer on Venus, one on Mars, and they’ve even been detected around icy moons in the Solar System.
There’s nitrous oxide, also known as laughing gas. It’s produced as an output by bacteria in the soil, and helps contribute to the Earth’s nitrogen cycle. And there’s good news, Earth seems to be the only world in the Solar System that has nitrous oxide in its atmosphere.
But scientists have also developed models for how this chemical could have been generated in the Earth’s early history when its sulfur-rich ocean interacted with nitrogen on the planet. In fact, both Venus and Mars could have gone through a similar cycle.
In other words, you might be seeing life, or you might be seeing a young planet.
Then there’s methane, the chemical we spent so much time talking about. And as I mentioned, there’s methane produced by life here on Earth, but it’s also on Mars, and there are liquid oceans of methane on Titan.
Astrobiologists have suggested other hydrocarbons, like ethane, isoprene, but these have their own problems too.
What about the pollutants emitted by advanced civilizations? Astrobiologists call these “technosignatures”, and they could include things like chlorofluorocarbons, or nuclear fallout. But again, these chemicals would be hard to detect light years away.
Astronomers have suggested that we should search for dead earths, just to set a baseline. These would be worlds located in the habitable zone, but clearly life never got going. Just rock, water and a non-biologically created atmosphere.
The problem is that we probably can’t even figure out a way to confirm that a world is dead either. The kinds of chemicals you’d expect to see in the atmosphere, like carbon dioxide could be absorbed by oceans, so you can’t even make a negative confirmation.
One method might not even involve scanning atmospheres at all. The vegetation here on Earth reflects back a very specific wavelength of light in the 700-750 nanometer region. Astrobiologists call this the “red edge”, because you’ll see a 5X increase in reflectivity compared to other surfaces.
Although we don’t have the telescopes to do this today, there are some really clever ideas, like looking at how the light from a planet reflects onto a nearby moon, and analyze that. Searching for exoplanet earthshine.
In fact, back in the Earth’s early history, it would have looked more purple because of Archaean bacteria.
There’s a whole fleet of spacecraft and ground observatories coming online that’ll help us push further into this question.
ESA’s Gaia mission is going to map and characterize 1% of the stars in the Milky Way, telling us what kinds of stars are out there, as well as detect thousands of planets for further observation.
The Transiting Exoplanet Space Survey, or TESS, launches in 2018, and will find all the transiting Earth-sized and larger exoplanets in our neighborhood.
The PLATO 2 mission will find rocky worlds in the habitable zone, and James Webb will be able to study their atmospheres. We also talked about the massive LUVOIR telescope that could come online in the 2030s, and take these observations to the next level.
And there are many more space and ground-based observatories in the works.
As this next round of telescopes comes online, the ones capable of directly measuring the atmosphere of an Earth-sized world orbiting another star, astrobiologists are going to struggling to find a biosignature that provides a clear sign there’s life there.
Instead of certainty, it looks like we’re going to have the same struggle to make sense of what we’re seeing. Astronomers will be disagreeing with each other, developing new techniques and new instruments to answer unsolved questions.
It’s going to take a while, and the uncertainty is going to be tough to handle. But remember, this is probably the most important scientific question that anyone can ask: are we alone in the Universe?
The answer is worth waiting for.
Researchers at Canada’s McGill University have shown for the first time how existing technology could be used to directly detect life on Mars and other planets. The team conducted tests in Canada’s high arctic, which is a close analog to Martian conditions. They showed how low-weight, low-cost, low-energy instruments could detect and sequence alien micro-organisms. They presented their results in the journal Frontiers in Microbiology.
Getting samples back to a lab to test is a time consuming process here on Earth. Add in the difficulty of returning samples from Mars, or from Ganymede or other worlds in our Solar System, and the search for life looks like a daunting task. But the search for life elsewhere in our Solar System is a major goal of today’s space science. The team at McGill wanted to show that, conceptually at least, samples could be tested, sequenced, and grown in-situ at Mars or other locations. And it looks like they’ve succeeded.
Recent and current missions to Mars have studied the suitability of Mars for life. But they don’t have the ability to look for life itself. The last time a Mars mission was designed to directly search for life was in the 1970’s, when NASA’s Viking 1 and 2 missions landed on the surface. No life was detected, but decades later people still debate the results of those missions.
But Mars is heating up, figuratively speaking, and the sophistication of missions to Mars keeps growing. With crewed missions to Mars a likely reality in the not-too-distant future, the team at McGill is looking ahead to develop tools to search for life there. And they focused on miniature, economical, low-energy technology. Much of the current technology is too large or demanding to be useful on missions to Mars, or to places like Enceladus or Europa, both future destinations in the Search for Life.
“To date, these instruments remain high mass, large in size, and have high energy requirements. Such instruments are entirely unsuited for missions to locations such as Europa or Enceladus for which lander packages are likely to be tightly constrained.”
The team of researchers from McGill, which includes Professor Lyle Whyte and Dr. Jacqueline Goordial, have developed what they are calling the ‘Life Detection Platform (LDP).’ The platform is modular, so that different instruments can be swapped out depending on mission requirements, or as better instruments are developed. As it stands, the Life Detection Platform can culture microorganisms from soil samples, assess microbial activity, and sequence DNA and RNA.
There are already instruments available that can do what the LDP can do, but they’re bulky and require more energy to operate. They aren’t suitable for missions to far-flung destinations like Enceladus or Europa, where sub-surface oceans might harbour life. As the authors say in their study, “To date, these instruments remain high mass, large in size, and have high energy requirements. Such instruments are entirely unsuited for missions to locations such as Europa or Enceladus for which lander packages are likely to be tightly constrained.”
A key part of the system is a miniaturized, portable DNA sequencer called the Oxford Nanopore MiniON. The team of researchers behind this study were able to show for the first time that the MiniON can examine samples in extreme and remote environments. They also showed that when combined with other instruments it can detect active microbial life. The researches succeeded in isolatinh microbial extremophiles, detecting microbial activity, and sequencing the DNA. Very impressive indeed.
These are early days for the Life Detection Platform. The system required hands-on operation in these tests. But it does show proof of concept, an important stage in any technological development. “Humans were required to carry out much of the experimentation in this study, while life detection missions on other planets will need to be robotic,” says Dr Goordial.
“Humans were required to carry out much of the experimentation in this study, while life detection missions on other planets will need to be robotic.” – Dr. J. Goordial
The system as it stands now is useful here on Earth. The same things that allow it to search for and sequence microorganisms on other worlds make it suitable for the same task here on Earth. “The types of analyses performed by our platform are typically carried out in the laboratory, after shipping samples back from the field,” says Dr. Goordial. This makes the system desirable for studying epidemics in remote areas, or in rapidly changing conditions where transporting samples to distant labs can be problematic.
These are very exciting times in the Search for Life in our Solar System. If, or when, we discover microbial life on Mars, Europa, Enceladus, or some other world, it will likely be done robotically, using equipment similar to the LDP.
It seems that every few months or so, breathless claims surface on the internet that NASA is about to make an Earth-shattering announcement about aliens … or UFOs … or killer asteroids … or some other sensational assertion. Or better yet, NASA is hiding these ‘facts’ from us.
The latest claims says that “NASA Is About to Announce the Discovery of Intelligent Alien Life,” and this one might be receiving more attention and credence than usual because the group making the claim is Anonymous, the notorious hacking and activist group.
However, before we get into their claim, for the record, this morning NASA’s Thomas Zurbuchen, the associate administrator for the Science Mission Directorate, tweeted, “Contrary to some reports, there’s no pending announcement from NASA regarding extraterrestrial life.”
Contrary to some reports, there’s no pending announcement from NASA regarding extraterrestrial life.
— Thomas Zurbuchen (@Dr_ThomasZ) June 26, 2017
Anonymous’ video has been viewed over a million times, and the video’s description claims, “Latest anonymous message in 2017 just arrived with a huge announcement about the Intelligent Alien Life. NASA says aliens are coming!”
The video is a rambling (over 12 minutes), rather incoherent collection of statements and quotes from various people and NASA websites. The main quote that is attributed to the alien life claim is from Zurbuchen, speaking at a House Science Committee hearing in April. The quote, taken a little out of context, is, “Taking into account all of the different activities and missions that are specifically searching for evidence of alien life, we are on the verge of making one of the most profound, unprecedented, discoveries in history.”
If you watch the House Science Committee hearing, Zurbuchen is talking about upcoming missions like the Mars 2020 rover and the Europa Clipper mission — both of which will look for sign of life and conditions suitable for life – as well as current missions like the Kepler telescope that has discovered and confirmed thousands of planets around other stars. Of course, Zurbuchen is talking about these missions in the most exciting way possible to make sure Congress is excited about these missions, too. But he certainly does not say that NASA has found alien life, or that they have evidence they will be revealing soon. He tweeted about that this morning, too.
Are we alone in the universe? While we do not know yet, we have missions moving forward that may help answer that fundamental question.
— Thomas Zurbuchen (@Dr_ThomasZ) June 26, 2017
Another quote in the video is a very old one from former NASA astronaut Dr. Brian O’Leary, who passed away in 2011. He was a planetary scientist who ended up leaving NASA in 1968 and never flew in space. I met O’Leary in the 1990’s and can confirm the statement on the Wikipedia page about him that he “increasingly explored unorthodox ideas.”
The video goes on to talk about the well-known discoveries of the Kepler mission, saying “Twenty-five years ago, we didn’t know that planets existed beyond our solar system. Today we have confirmed the existence of over 3,400 exoplanets that orbit other suns, and we continue to make new discoveries.”
It also discusses other well-publicized discoveries such as finding the key ingredients for life on Saturn’s moon Enceladus, but offers no sources of facts when the Guy Fawkes look-alike says, “There are many who claim that unofficially, mankind has already made contact with aliens and not just little micro-organisms floating around inside a massive alien ocean, but advanced space-faring civilizations.”
All the claims in the video that “aliens are on the way” are nothing but speculation and the quotes from NASA officials and scientists are all in the public domain, easily found online, so there is nothing being “revealed’ here. I’ve talked to scientists from all around the world, and if NASA or any other space agency had found evidence of alien life, they’d be shouting it from the rooftops, not hiding it.
The search for life in the Universe takes many paths. There’s SETI, or the Search for Extraterrestrial Intelligence, which is searching for signals from a distant ancient civilization. There’s the exploration of our own Solar System, on Mars, or underneath the subsurface oceans of Europa and Enceladus, to see if life can be anywhere there’s liquid water and a source of energy. And upcoming space telescopes like James Webb will attempt to directly image the atmospheres of distant extrasolar planets, to see if they contain the distinct chemical signatures of life.
But according to Jason Wright, an astronomer at the Center for Exoplanets and Habitable Worlds at Penn State University, we could consider searching for evidence of ancient civilizations right here on Earth, or across the Solar System. Don’t get excited, though, so far “there is zero evidence for prior indigenous species in the Solar System.”
In a paper, recently submitted to the arXiv electronic preprint archive entitled Prior Indigenous Technological Species, Dr. Wright describes how we might go about searching for the technological artifacts left behind by ancient civilizations that have evolved in the Solar System. Perhaps on an ancient, cooler Venus, or on Mars in a time when it was wetter and had a thicker atmosphere. Those civilizations could have arisen millions or even billions of years ago, destroyed themselves or left the Solar System, and only ancient traces of their culture and technology would still be around.
If a civilization had reached a high level of technology, where did it go? Wright suggests a variety of catastrophes, like a swarm of comets, self destruction, or even a nearby supernova explosion that irradiated the whole Solar System with high energy gamma rays. Even without a specific event, a civilization might have simply just died out, or became permanently non-technological. Of course, these possibilities face our own human civilization. It’s hard to read the paper and not consider the fate of humanity. Will future aliens search for scraps to learn about us?
Where should we look? According to Wright, Earth is the obvious, most habitable place in the Solar System, and it’ll be the easiest to search. Humans have dramatically changed the landscape of Earth. Our open pit mines, for example, are a clear indication that an intelligent species dug out a specific mineral from the ground. These might be obvious for millions of years, but over the course of billions of years, plate tectonics will have recycled those regions, absorbing the evidence back into the ground. Radioactive isotopes from ancient nuclear reactors, or fossils of ancient beings will have about the same lifespan. Beyond a few hundred million years, the Earth itself would have completely obscured any evidence of a technological civilization.
Venus is inhospitable today, but it might not have always been the case. Billions of years in the past, when the Sun was cooler, it might have had a thinner atmosphere and milder temperatures. It’s worth searching. That said, it appears that Venus has gone through major geological resurfacing events, where the entire planet’s surface turned inside out. Venus could easily hide its secrets.
Scientists are accumulating more and more evidence that Mars was warmer and wetter in the past, with eras when liquid water could exist on the surface for long periods of time. And unlike Earth and Venus, it doesn’t have active plate tectonics. Landscapes on the surface have remained there for billions of years. Well, okay, they’ve been pounded by meteorites, but they’re still there.
What should we be looking for? One idea is technological structures: ancient mining facilities, factories, even cities. On Mars, these structures could get covered by dust or worn down by erosion, so it’s entirely possible our space-based observations could have missed them. Even structures on asteroids and the Moon get eroded by micrometeorites wearing them down. Over the course of millions years, an ancient factory would look very similar to a small rocky outcrop. The real evidence could be hidden underground, safely protected from the surface erosion. We need more rovers and orbiters with ground penetrating radar to see below the surface.
There could be free-floating objects in the Solar System, like ancient space stations. Of course, if they’ve been abandoned long ago, they wouldn’t be functional, and that same micrometeorite erosion would have worn them down over the vast timescales. Furthermore, their orbits might not be stable, and could eventually crash into another world, or get kicked out of the Solar System entirely. Space stations out in the Kuiper Belt would be subject to less erosion, and better preserved over vast timescales. We need better telescopes and deeper surveys to answer this question.
The bottom line is that Dr. Wright doesn’t conclude there’s any evidence for ancient civilizations in the Solar System so far. But the reality is that we’ve only just begun to look. NASA’s Mars Reconnaissance Orbiter, which contains the most powerful telescope to ever travel away from the Earth has only mapped a few percent of the Martian surface at its highest resolution. Astronomers have only mapped a tiny fraction of the asteroids and comets zipping around the Solar System. And we’ve only had single glimpses at places in the outer Solar System, like Uranus, Neptune and Pluto.
There’s so much more searching that needs to be done. But while we’re at it, we should keep an eye out for ancient civilizations. If we did find an old factory, space station, or even the dumping ground of a precursor species, it would be a boon to our knowledge.
And might just give us a warning; advanced knowledge of what the future holds for our own civilization.
Original Source: Prior Indigenous Technological Species
For a long time, the idea of finding life on other worlds was just a science fiction dream. But in our modern times, the search for life is rapidly becoming a practical endeavour. Now, some minds at NASA are looking ahead to the search for life on other worlds, and figuring out how to search more effectively and efficiently. Their approach is centered around two things: nano-satellites and microfluidics.
Life is obvious on Earth. But it’s a different story for the other worlds in our Solar System. Mars is our main target right now, with the work that MSL Curiosity is doing. But Curiosity is investigating Mars to find out if conditions on that planet were ever favorable for life. A more exciting possibility is finding extant life on another world: that is, life that exists right now.
At the Planetary Science Vision 2050 Workshop, experts in Planetary Science and related disciplines gathered to present ideas about the next 50 years of exploration in the Solar System. A team led by Richard Quinn at the NASA Ames Research Center (ARC) presented their ideas on the search for extant life in the next few decades.
Their work is based on the decadal survey “Vision and Voyages for Planetary Science in the Decade 2013-2022.” That source confirms what most of us are already aware of: that our search for life should be focussed on Mars and the so-called “Ocean Worlds” of our Solar System like Enceladus and Europa. The question is, what will that search look like?
Quinn and his team outlined two technologies that we could center our search around.
A nanosatellite is classified as something with a mass between 1-10 kg. They offer several advantages over larger designs.
Firstly, their small mass keeps the cost of launching them very low. In many cases, nanosatellites can be piggy-backed onto the launch of a larger payload, just to use up any excess capacity. Nanosatellites can be made cheaply, and multiples of them can be designed and built the same. This would allow a fleet of nanosatellites to be sent to the same destination.
Most of the discussion around the search for life centers around large craft or landers that land in one location, and have limited mobility. The Mars rovers are doing great work, but they can only investigate very specific locations. In a way, this creates kind of a sampling error. It’s difficult to generalize about the conditions for life on other worlds when we’ve only sampled a small handful of locations.
On Earth, life is everywhere. But Earth is also the home to extremophiles, organisms that exist only in extreme, hard-to-reach locations. Think of thermal vents on the ocean floor, or deep dark caves. If that is the kind of life that exists on the target worlds in our Solar System, then there’s a strong possibility that we’ll need to sample many locations before we find them. That is something that is beyond the capabilities of our rovers. Nanosatellites could be part of the solution. A fleet of them investigating a world like Enceladus or Europa could speed up our search for extant life.
NASA has designed and built nanosatellites to perform a variety of tasks, like performing biology experiments, and testing advanced propulsion and communications technologies. In 2010 they successfully deployed a nanosatellite from a larger, microsatellite. If you expand on that idea, you can see how a small fleet of nanosatellites could be deployed at another world, after arriving there on another larger craft.
Microfluidics deals with systems that manipulate very small amounts of fluid, usually on the sub-millimeter scale. The idea is to build microchips which handle very small sample sizes, and test them in-situ. NASA has done work with microfluidics to try to develop ways of monitoring astronauts’ health on long space voyages, where there is no access to a lab. Microfluidic chips can be manufactured which have only one or two functions, and produce only one or two results.
In terms of the search for extant life in our Solar System, microfluidics is a natural fit with nanosatellites. Replace the medical diagnostic capabilities of a microfluidic chip with a biomarker diagnostic, and you have a tiny device that can be mounted on a tiny satellite. Since functioning microfluidic chips can be as small as microprocessors, multiples of them could be mounted.
” Technical constraints will inevitably limit robotic missions that search for evidence of life to a few selected experiments.” – Richard.C.Quinn, et. al.
When combined with nanosatellites, microfluidics offers the possibility of the same few tests for life being repeated over and over in multiple locations. This is obviously very attractive when it comes to the search for life. The team behind the idea stresses that their approach would involve the search for simple building blocks, the complex biomolecules involved in basic biochemistry, and also the structures that cellular life requires in order to exist. Performing these tests in multiple locations would be a boon in the search.
Some of the technologies for the microfluidic search for life have already been developed. The team points out that several of them have already had successful demonstrations in micro-gravity missions like the GeneSat, the PharmaSat, and the SporeSat.
“The combination of microfluidic systems with chemical and biochemical sensors and sensor arrays offer some of the most promising approaches for extant life detection using small-payload platforms.” – Richard.C.Quinn, et. al.
Putting It All Together
We’re a ways away from a mission to Europa or Enceladus. But this paper was about the future vision of the search for extant life. It’s never too soon to start thinking about that.
There are some obvious obstacles to using nanosatellites to search for life on Enceladus or Europa. Those worlds are frozen, and it’s the oceans under those thick ice caps that we need to investigate. Somehow, our tiny nanosatellites would need to get through that ice.
Also, the nanosatellites we have now are just that: satellites. They are designed to be in orbit around a body. How could they be transformed into tiny, ocean-going submersible explorers?
There’s no doubt that somebody, somewhere at NASA, is already thinking about that.
The over-arching vision of a fleet of small craft, each with the ability to repeat basic experiments searching for life in multiple locations, is a sound one. As for how it actually turns out, we’ll have to wait and see.
Scientists have found evidence that life existed on Earth much earlier than previously thought and they say this discovery has implications for life springing up on other planets, particularly Mars.
Fossils of microscopic bacteria were discovered in Quebec, Canada in the Nuvvuagittuq Supracrustal Belt, a formation which contains some of the oldest sedimentary rocks in the world. Scientists estimate the fossils are at least 3.7 billion years old, and could be as old as 4.28 billion years. This is hundreds of millions of years older than previously found specimens.
“The most exciting thing about this discovery is that we know life managed to get a grip and start on Earth at such an early time in Earth’s evolution, which gives us exciting questions as to whether we are alone in the solar system or in the universe,” said PhD student Matthew Dodd from University College London (UCL), who is the first author on a new paper about the finding in the journal Nature. “If life happened so quickly on Earth then could we expect it to be a simple process and start on other planets, or was Earth really just a special case?”
The tiny fossils are the remains of microorganisms that are smaller than the width of a human hair. The Nuvvuagittuq rocks are thought to have formed in an iron-rich deep-sea hydrothermal vent system that provided a habitat for Earth’s first life forms. These rocks are mostly composed of silica and hematite.
“Our discovery supports the idea that life emerged from hot, seafloor vents shortly after planet Earth formed,” Dodd said in a press release. “This speedy appearance of life on Earth fits with other evidence of recently discovered 3,700 million year old sedimentary mounds that were shaped by microorganisms.”
Prior to this discovery, the oldest microfossils reported were found in Western Australia and were dated at 3.4 billion years old, leading scientists to speculate that life probably started around 3.7 billion years ago. But the new finding suggests that life existed as early as 4.5 billion years ago, just 100 million years after Earth formed.
“The microfossils we discovered are about 300 million years older than the previously thought oldest microfossils,” said Dr. Dominic Papineau, a professor of geochemistry and astrobiology at UCL, “so they are within a few hundred million years from within the accretion of the solar system and the planet Earth and the Sun and the Moon and so on.”
Papineau said the structures in the rocks that contained the fossils were spheroids, and since they are made of hematite, they are reminiscent of the discovery in 2004 by the Mars Exploration Rover Opportunity of beds of rounded hematite concretions, that MER scientists called “blueberries.” These rounded concretions formed on Earth when significant volumes of groundwater flowed through permeable rock, and chemical reactions triggered minerals to precipitate and start forming a layered, spherical ball.
The concretions may bear on the search for evidence of past life on Mars because bacteria on Earth can make concretions form more quickly, according to previous research.
“The origin of this structure is not fully understood even on Earth where we find them,” Papineau said. “We don’t know really how organic matter can potentially be involved in making these structures.”
Both the MER rovers, Opportunity and Spirit, as well as the Curiosity rover have all found evidence of past water on Mars. In addition, Curiosity has identified traces of elements like carbon, hydrogen, nitrogen, oxygen, and more — the basic building blocks of life. It also found sulfur compounds in different chemical forms, a possible energy source for microbes. If Mars really was warmer and wetter in the past, as the evidence seems to point, Mars would have been the perfect spot for living organisms.
While the finding of ancient fossils on Earth doesn’t necessarily mean there is past or present life on Mars, in conjunction with the Curiosity rover finding of the raw ingredients for life, it is enticing to know that the environment on early Mars was likely very similar to early Earth, where life did spring up.
You can see details and hear the researchers talk about their findings in the video below: