Are We Alone? | Ellen Stofan | TEDxBinghamtonUniversity

Ever since humans first walked on this planet, they have looked up at the night sky at all those bright points of light and wondered if those other suns shining on other Earths are life unique to our own planet or if they have taken hold somewhere. another place. the universe we are

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we are about to answer that question this image of a star field that you see behind me those small boxes in the center of the image that is where NASA's Kepler space telescope has been looking for the five years it has been I've been looking at that area of ​​the night sky that, if you went out tonight and gave a thumbs up, you would actually be covering roughly the area of ​​the sky that Kepler has been studying in that small area of ​​the night sky that Kepler has found over 5,000 planet candidates. five thousand when I go out in public and talk to children I say, you know, when I was a child we had nine planets, you only have eight, but now you have thousands, thousands, and what about those thousand planets?

Are we that interested? We're looking for a habitable planet around another star and Earth 2.0, so to speak. This is an image of our planet taken by NASA's Epic Camera on NOAA's Discover spacecraft and it really shows what we're looking for, that blue dot, that blue marble. in space because what we are looking for is a planet with water, we believe that water is fundamental for life. Water has unique properties. It is a solvent. Many things dissolve in it, such as nutrients that are essential for life. Water is also unique because it happens. In all three phases it contains liquid and solid in a relatively narrow temperature range, so we really believe that water is essential for life, which is why we are looking for that blue planet in space and we are about to be able to study it.

This is the James Webb Space Telescope being built right now at our Goddard Space Flight Center in Maryland. James Webb is our next generation space telescope, following the Hubble Space Telescope. It is made up of 18 mirrors, each of which is the size of a coffee. chart The Hubble Space Telescope actually orbits the Earth, but the James Webb Space Telescope will orbit the Sun about a million miles from Earth and when deployed in space those 18 mirrors will act together as a 21-foot mirror and a telescope space telescope has advantages over a ground-based telescope here on Earth, for starters it can run 24/7, you don't have to wait for nighttime and you don't have to worry about atmospheric conditions like we do with telescopes here on this planet.

So what is the James Webb Space Telescope going to do? It will look further and further into space, deeper into space almost to the time of the Big Bang, to understand what happened in the earliest period of the universe, how the Howard galaxies formed, how they form. stars that form, how planetary systems form, but even more importantly, the James Webb Space Telescope will look at the atmospheres of some of those planets that Kepler has discovered around other stars and look for planets in what we call the habitable zone or, sometimes it calls the Goldilocks zone, you know, Venus is too hot right now.

Mars is smothered to the point of cooling and Earth is perfect for liquid water on the surface, so we're looking for that planet just the right distance from its parent star where there's water. it might be stable, sir, and then James Webb will look at the gases in that atmosphere. Now, what type of gases are we looking for? Well, those we know from here on Earth, an atmosphere like ours, nitrogen, carbon dioxide, methane gases that we associate with. life now if we find that that is the proof of life no, it is simply consistent to say that maybe this planet could be habitable what we would really like to do over time is see changes in those gases that would indicate that there is something dynamic happening now that could It may be volcanism, but we hope that maybe there could be life now.

To image that planet around another star, we need a really powerful telescope that right now we need to invest in the technology to be able to build it and, in fact, it might have to be. so big that we would have to build it in space, so I hope that happens in our lifetime or definitely in my children's lifetime, but James Webb will really take us down this path of trying to find that habitable planet that is Earth 2.0 now , when we think about life it is important to reflect on life here on earth behind me you see volcanic vents at the bottom of the earth's ocean they are called black smokers or white smokers because those things that come out of the top of them the earth here on earth life began in the oceans the earth formed about 4.6 billion years ago, about 700 million years after the earth formed, around the time conditions stabilized, life evolved here on the earth, but remained in the oceans for more than a billion years and, in fact, only in the last 500 million.

More complex life forms as we know them evolved years ago, land plants, fish, and it's only been 200,000 years since we had humans on this Earth, so based on our only data point from our only planet, we think that the Life might be easy, but complex life is. It's probably difficult, but these black smokers that we see at the bottom of the ocean are extremely rich environments for life that arises from those volcanic eruptions and they contain all kinds of nutrients, so even in this extreme environment in the deep ocean where we don't there is sunlight in extremely hot climates.

Aquatic life is flourishing. NASA-funded researchers have traveled around the world, visiting places such as the Dry Valleys of Antarctica. Chile's Atacama Desert, one of the driest places on Earth. These places are exc

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t analogues of four planets like Mars, where we think there could be life. What if those researchers discovered that life persists here on Earth even in these extreme environments in the deep ocean? If you go down to the Mariana Trench, which is a deep crack in the ocean, but at the bottom of the Pacific Ocean, five miles deep, we can still find fish adapted to that dark environment seven miles deep.

The research has surprised researchers to see that microbes are abundant in water. Life persists on this Earth and it is very common and that is what gives us confidence when we go out into the solar system and makes us wonder if there could be life in our own solar system, in our own celestial backyard, so where do we go to look ? One of the things we're focusing on at NASA is the ocean worlds in the outer solar system, so now we're moving away from that habitable zone concept on these worlds so far away in our own solar system, near Jupiter, the Saturn's waters are no longer stable on the surface, it is too cold, in fact, the surfaces of these moons are actually made of water ice, but it is difficult for it to behave like a rock, so where are the oceans?

They are under those frozen crusts. Deep water oceans perhaps a mile or so below the surface. This bottom image is Enceladus. It's a moon of Saturn and those bright columns you see erupting like geysers coming from there. The liquid ocean beneath Enceladus. We've flown NASA's Cassini spacecraft through those plumes. That's why we know its water. We've also measured minerals that indicate there could be some of those eruptions, like those black smokers we were observing in Enceladus' subsurface oceans. and we've even measured organic molecules, but our instrument at Cassini wasn't sophisticated enough to tell us exactly what they were.

We're always looking for things like amino acids. We have found amino acids in comets in interstellar clouds and those are. the building blocks of life on Earth, so we want to go back to Enceladus and study those eruption plumes in more detail Europa is the moon at the top right is a moon of Jupiter icy crust subsurface liquid ocean like Enceladus all those cracks that You see what's on the surface is coming from the ocean and moving beneath the surface in the mid-2020s. NASA will send a spacecraft to Europa that will find out what that kind of orange and brown gunk on the surface is.

Could it be organic material? Could Europe have erupted? columns like Enceladus where we could go and find out if there is life in those underground oceans every time we measure one of those volcanic events here on Earth again extremely rich environments for life and that's what makes us so optimistic about Europa about Enceladus now the moon the top left is a slightly different story it is another moon of Saturn called Titan Titan is the only moon in the solar system with an atmosphere its atmosphere is almost mainly nitrogen like Earth's atmosphere it rains on Titan Titan has rivers lakes seas but It is extremely cold on the surface of Titan remember it is an orbit around Saturn 90 million miles from earth so what is that fluid that is raining down?

Turns out it's liquid methane, liquid ethane, basically gasoline, how exotic is that, but again it rains, it forms rivers, now it forms seas. I've talked time and time again about how important water is to life, but what if we're wrong? What if we're only seeing a small piece of the puzzle because of what we know about Earth? What if all you need is a fluid Titan? It would help us push the limits of what we understand about life. What are the limits of life? Does it require water? Could it look very different from life on Earth?

Titan is an important piece of that puzzle, and besides, how cool would it be to sail a ship? in an alien sea, but if we look across the solar system, let's go back to the habitable zone and Mars is definitely NASA's biggest target to really answer this question: did life evolve beyond Earth? We know from the landers and orbiters that NASA and other space agencies around the world have sent to Mars, we know that Mars had water on its surface very early in its history and our Curiosity rover, which has been studying Mount Sharp, This mountain that you see behind me has been slowly climbing Mount Sharp and reading each of those layers of the surface of Mars because for a geologist each of those layers of rock is like a page in the history book of Mars, So when we look at those layers, we wonder what they've been telling us, that not only was water stable on the surface of Mars for about a billion years, the environment was actually quite conducive to life, but then Mars lost its magnetic field that protected its atmosphere.

We know from our NASA MAVEN spacecraft that the solar wind, the stream of particles coming from the Sun, began to strip away the upper layers of Mars' atmosphere. Mars cooled, its atmosphere became very thin, the water went underground, it was lost in space and what if there had been life on Mars? Would life have submerged to that extreme? environment that suddenly passed to Mars or became extinct so the only evidence we could find today would be from fossil microbes because remember that life on Earth after about a billion years in the ocean was still only unicellular or multicellular.

Cellular life was not very complex, so while NASA rovers and orbiters are important, I think it will take humans, and not just any humans, but geologists, astrobiologists, people like me on the surface of Mars, opening up a lot of rocks. and analyzing them to actually find out if life evolved on Mars because, again, those fossil microbes are going to be hard to find, so NASA right now is embarking on a trip to Mars, the president has a goal of getting humans to Mars in the 2030s and NASA will do it with Our international partners and with the private sector we work on it every day and those humans are really critical again to answer this question: are we

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from all the images that NASA has taken?

I find this the most inspiring and the most humbling. Is called. the Hubble Deep Field image, the Hubble Space Telescope looked for days at the darkest area of ​​the sky where there seemed to be nothing, looked beyond our galaxy, the Milky Way, beyond nearby galaxies that receive light from very far away and when a telescope receives light from far away, it takes so long for those photons to reach your telescope, you are actually looking back in time this image you can see these galaxies behind me those are not stars those are galaxies those galaxies are They formed about 500 mm years after the Big Bang approximately 13 billion years ago incredible complexity incredible beauty in the very early universe from our Hubble space telescope we know that there are billions of galaxies we know that in each of those thousandsof millions of galaxies there are billions of stars how many of those stars have solar systems like ours we have Earth 2.0 s we have the technology we know where to go we know what to measure we will go to Mars not only with robotic spacecraft but with humans to discover if any Once life evolved on the Red Planet we will go to the ocean worlds of the outer solar system and the Salad They assist Europa, even Titan, to discover what the limits of life are in our solar system and we will continue to use our powerful telescopes to answer that fundamental question.

We're alone? Thank you.