What Do Aliens Look Like?

from Through the Wormhole; They're out there. We can see them. For the first time in human history, we know the Universe is filled with planets stranger than we could ever have imagined planets that might be home to extraterrestrial life. But what will these creatures look like? We're all products of our environment. We can't know the face of an alien until we're staring at it. But like detectives on the hunt for an unknown suspect, biologists and planetary scientists are beginning to piece the puzzle together. Some of the clues are out there, but a lot of them are right here. To get home from school every day, I had to cut through the yard of a scary, old house. I never saw anyone come in or out of it, but someone or something lived there. I could only imagine who or what it might be. Harvard paleontologist Andrew Knoll has spent his life studying creatures beyond our wildest imaginations. One of the things you learn when you go through a museum is that not only is it hard to imagine what life might be on another planet, but it's hard to imagine some of the life that has existed on this planet. For the past eight years, Andrew has served as mission biologist on NASA's Mars Rovers. A rock, which formed about 31/2 billion years ago, is full of iron minerals, which means that iron had to be able to be transported through seawater. These various earths hotter, colder, with more or less oxygen were essentially alien worlds. So, for Andrew, the best place to discover what aliens might look like is in our own fossil records. These are trilobites. Now, when you look at this, you'll see things that are familiar. There is a jointed, segmented body. If Earth in the past has been as alien as planets orbiting other stars, then aliens you've seen in movies lizards with two eyes, two arms, and two legs might be pretty close to the mark. University of Chicago Professor Michael Labarbera is an expert in biomechanics. He's trying to predict how aliens will walk, fly, and swim by searching for the basic rule of how animals move. You could call it the lowest common denominator of locomotion. Things like horseshoe crabs were crawling out on the beach and laying their eggs when pterodactyls were flying in the sky. One of the features that we share with these animals is a lever-type skeleton. A torso with jointed limbs acting as levers. It's a good basic anatomy of an alien, but can we get closer to imagining their true form? In the 19th century, Charles Darwin kept a series of notebooks chronicling how the shapes of animals had evolved to adapt to the environments they lived in. What would a book of life on other planets look like? What mind-bending, anatomical adaptations might develop in alien surroundings? The environment shapes creatures depending on their ecology. Density of the atmosphere, whether or not you have a world-covering ocean, is gonna make a big difference in the history and, thus, in the shape of the organisms. Which is why to know what aliens look like, we must learn more about the planets they live on. Until very recently, we had no proof other planets existed, let alone any idea what their landscapes or atmospheres might be like. But now, for the first time in human history, we can see worlds far outside our solar system. And now that we know where E.T.s could live, we're getting closer to revealing their hidden faces. If we want to know what aliens look like, we first have to know something about the places they live. Until recently, this was impossible. Our telescopes could only see stars, not the planets that orbit them. Today, alien hunters have a dedicated research ship floating 20 million miles from Earth, and it's discovering new worlds by the thousand. In 2009, NASA launched its latest space telescope Kepler. Harvard professor Dimitar Sasselov is one of Kepler's lead scientists. Perhaps the most intriguing of Kepler's discoveries are around 300 super-sized versions of Earth planets made of rock, but up to five times as heavy. If anyone can imagine the landscapes where aliens might jog, swim, or glide, it's Diana Valencia. Part-time triathlete, she's one of the first geologists to break ground on these super earths. I do not have a hammer. I do not break up rocks. What I do is I do numerical models to understand how the Earth works and use that to understand how bigger earths and similar planets work, as well. To understand whether the super earths could harbor life, Diana is zeroing in on the basic geological engine that powers rocky planets plate tectonics. From Diana's geological perspective, this cycling of material from the inside of our planet to the atmosphere has been vital to the evolution of life. If you are a creature in a planet that doesn't have a geomagnetic field, you are being bombarded by high-energy particles, and those are interacting with your cells, causing mutations, probably. So, you have to be clever, as an organism, to adapt to those conditions. What kind of alien could survive on a radiation-soaked super earth? It would need a protective shell, perhaps laced with heavy metals like lead. Inhabitants of rocky super earths might look surprisingly familiar. But imagine a world where there is no rock, and where creatures living in the ocean also fly through the sky. On Earth, evolution has produced countless variations on life animals that glide through the water and soar through the sky. Beings that slither, crawl, walk, and run. If life on other worlds follows the evolutionary pattern of life here, what other mind-bending features might arise? At M.I.T. in Cambridge, astrophysicist Sara Seager and biochemist William Bains are beginning to imagine what these distant worlds will be like. The atmosphere's gonna come from somewhere, so you're gonna have volcanoes producing atmosphere. They're trying to predict how a planet's size and composition will shape its biosphere. Before the discovery of exoplanets, people thought that all planetary systems would be like our solar system. Most science fiction assumes that aliens are gonna be walking around, they're gonna be breathing air. On Earth, an environment like this with boiling water and steam is inimicable to nearly all life. But we're trying to imagine an alien world in which this is the normal environment, and we can now start to model a planet that has a huge ocean covering it and nevertheless is incredibly hot. That makes us think about, "Could there be life in the ocean? Can the chemistry work? And if it can, what would it look like?" A molecule like DNA wouldn't survive these conditions, but William believes more heat-tolerant genetic material would likely evolve. What is so fascinating so far in exoplanets, anything is possible within the laws of physics and chemistry, and anything we imagine will exist somewhere. Follow the water. There, you'll find life. That's what the astrobiologists like to say. But what if there is no water? What about planets enveloped in toxic air where the building blocks of life are completely different from our own? Could they also be alive? Life is tenacious. Everywhere on Earth, from the coldest depths of the sea to the boiling fissures of volcanoes, living things find a way to thrive. But the conditions on alien planets could be even more extreme. We're discovering worlds of fire and ice, worlds of permanent night, worlds where hurricanes are constant and global. What kind of alien could live in these hellish places? Gliese 581D floats 20 light-years away from Earth in the constellation Libra. It's one of the small group of planets we have spotted that might harbor alien life. These kite plants have to be able to get up into the higher regions of the atmosphere in order to get enough light, and the way they do that is to utilize the shear in the atmosphere. Michael's kite requires two forces to stay aloft and stable wind to lift the kite, and an anchor to keep it from blowing ever upward. The alien kite plant works much the same way. So, what we've posited for this particular plant is a lifting surface on one end of the string, and at the other end of the string, something that functions like a parachute that produces a drag force. Here on Earth, over hundreds of millions of years, billions of different creatures competed for survival, but eventually, a special mutation enabled one animal to become the planet's top predator. That mutation was the human brain. Somewhere out in space, alien evolution should have created beings at least as smart as we are. What do intelligent extraterrestrials look like? This man thinks he knows, and the answer could be bad news for life on Earth. With each new world we discover, we come one step closer to finding evidence of life beyond Earth and perhaps to fulfilling our dreams of communicating with alien life-forms. But if that day ever comes, we'd better brace ourselves for a shock, because many scientists think they may not look like living beings at all. For the past 50 years, the search for extra-terrestrial intelligence, SETl, has attempted to capture any glimmer of communication from alien worlds. For Seth Shostack, SETl's senior astronomer, it's a search for our distant cosmic image, for a species with a brain at least as smart as ours. When it comes to intelligent life, we haven't found it. It would be wrong for us to think we're the end of evolution, too, obviously. So, where will evolution take us next? And where is it likely to have taken alien civilizations? Seth thinks we need to look at our computers for the answer. Since the 1970s, when floppy disks were the gold standard, this speed at which computers process instructions has increased more than 100,000 times. Today, for $1,000, you can buy a computer that has, if you will, the thinking capability or at least the computational capability of a lizard. Not so interesting. But by 2020 or 2025, $1,000 will buy you a laptop that has the same computational power as a human brain. The IQs of artificial brains are going from zero to 200 in the historic blink of an eye. How would a similar trajectory play out on a planet that is a mere 500 years ahead of us? On some distant planet, the book of life may no longer contain any biological forms. And if mechanical life has enough power, there's no limit to how large or complex it can become. Or maybe they've reorganized themselves so that they can share the thinking load amongst many members of the species, like distributed processing with computers. I mean, why should the aliens be content to be stuck with a kind of intelligence that can fit inside their heads? Alien evolution could produce a living machine planet throbbing with the combined intelligence of billions of alien minds. If such advanced life exists, how would we spot it? And should we even want to? Will aliens welcome us as friends or view us as threats? Or perhaps see Earth as a world to conquer? We wonder what aliens look like, but what do we look like to them? This woman has put herself inside their heads, and she believes she has the answer. As long as humans have looked up at the night sky, we have wondered whether something or someone out there is looking back. We want to know what aliens look like. What do we look like to aliens? If there is intelligent life out there, does the Earth look like a place worth visiting? May 29, 2008. 31 million miles out in space, the eyes of a technologically advanced race scan our planet for the signatures of life. Not aliens, but this was still a close encounter of an extraordinary kind. It was the NASA space probe Epoxi. Sent out to get closeups of comets, Epoxi briefly turned its lens back to its mother planet. And for the first time, we saw the Earth as aliens might see us. Astrophysicist Sara Seager was part of the Epoxi team. Sara normally studies exoplanets, looking for clues about alien atmospheres and ecosystems. The Epo xi probe gave her the chance to find out what Earth might look like to an alien astronomer. If you pretend you know nothing about Earth, what could you learn about Earth? An alien would be able to pick out Earth's rotation rate. They would be able to notice that we have surfaces of very different reflectivity that's cloud, land, and ocean. And they could also see that we have weather. They would see variability that isn't related to the rotation rate of Earth. The second thing Epoxi did was look at a spectrum of Earth that is, take the white light and split it up into

What kind of alien could survive on a radiation-soaked
What kind of alien could survive on a radiation-soaked

It's very possible that these planets do not have a molten core

NASA space probe Epoxi
NASA space probe Epoxi

Biologists think that life out there might look earth-like
Biologists think that life out there might look earth-like
  the different colors and to check and see if any of those colors were missing. We call that a spectrum. The spectrum of Earth's colors are like a flag announcing the presence of life on our planet. The blue of the oceans, the white of the clouds, the green of the land are all markers of an active ecosystem. If an alien is looking back at us from far away, the aliens would see that we have oxygen in the atmosphere. In fact, our atmosphere has 20% oxygen by volume. What's so fascinating is that, without life, our Earth would have basically 10 billion times less oxygen. So, oxygen would be essentially non-existent on Earth. And oxygen on Earth is created by life, so those aliens would know that oxygen in such large quantities should not be in our atmosphere unless it is being continually produced by something. And nothing that we know of in geophysics can produce so much oxygen. And that's why we attribute it to life. Aliens might see that our planet supports life, but they might not see that Earth is technologically advanced. They would have to look carefully to detect things like atmospheric pollution or the heat signatures of our cities. Reading the colors of our world and the millions of others like it out in the Universe would be easy for an advanced alien civilization. Unfortunately, it is not yet easy for us. Spotting exoplanets pushes the limits of current technology. If we want to see colors, we need a new set of tools. Astrophysicist Dimitar Sasselov wants to do something about that. The astro-comb that you see here is the technological breakthrough which was needed to bridge that gap.     When we see the true colors of other worlds, we will know where and how life is distributed across the Universe. And the next phase of our quest for alien life will begin. Where will it take us? What exciting, new worlds will we see? What new and unexpected creatures might live on them? Biologists think that life out there might look earth-like, but it won't look human. With so many planets out there, so many chances at life, we could have human-like relatives on a far-away earth. Creatures like us, perhaps as anxious as we are to know if they are alone in the Universe. As our tools improve, so do our odds of finding them. It is clear that we're in a new age of exploration and discovery. It hasn't been for 500 years that people have tried to discover planets around other stars. Now we have them. We have much more to explore, and the best is yet to come. 1,000 years from now, when people look back at our generation and ask, "What are the biggest accomplishments?" I like to think of these people making interstellar journeys and looking back and thinking we were the ones who started it all. What do aliens look like? What are the limits of our imagination? The true face of an alien will probably defy our scientific speculations. But our efforts won't be wasted, even if we do get all the details wrong. Our eternal intrigue about alien life and our persistent fear of it both rise from the same source the quest to understand our place in the family of life-forms that populate the cosmos. Know that, and we'll know the destiny of humankind.
List with pictures of the scientists, in order of their appearance in Through the Wormhole What Do Aliens Look Like? documentary, who share us their knowledges:
Andrew Knoll
Andrew Knoll (paleontologist, Harvard, NASA's Mars Rovers)
  Michael Labarbera
Michael Labarbera (biomechanical, University of Chicago)
  Dimitar Sasselov
Dimitar Sasselov (Kepler's lead scientists, Harvard)
  Diana Valencia
Diana Valencia (geologist)
  William Bains
William Bains (biochemist, M.I.T.)
  Sara Seager
Sara Seager (astrophysicist, M.I.T.)
  Seth Shostack
Seth Shostack (SETI's senior astronomer)