EZScience Episode 2 The Search for New Planets

(serene music) - Welcome to another episode of E.Z. Science, I'm Ellen Stofan, the John and Adrienne Mars Director of the Smithsonian's National Air and Space museum, or Dr. E. - And I'm Thomas Zurbuchen, the associate administrator for science at NASA, also referred to as Dr. Z. - We're here today to talk about a subject that's pretty near and dear to my heart, and that's the Hubble Space Telescope. You can see behind us, the structural dynamic test vehicle of Hubble and off to the side here, at the National Air and Space Museum, we have some of the instruments that were actually brought back from Hubble, the ones that weren't working so well, they had to put new instruments up on board, so if you haven't been here before, come and see this amazing history of Hubble. - To me this is one of the real highlights in the museum, and kind of every time I'm here I'm standing I'm in awe. So first of all, this mission is what I would consider the most important discovery machine we've ever done. If you look at that mission, last year alone, there are close to a thousand new publications written, it's not just a science mission, it's a science mission enabled by human exaperations, by astronauts. - [Dr. E] The fact that the astronauts were able to go up in shuttle and replace the instruments, constantly putting better, more advanced instrumentation on board, has really allowed Hubble over its twenty-nine years to completely change our view of the universe. - So there's a story that was out there about a planet called 'K2-18B' and here's a question regard with the hashtag 'E.Z. Science', and it said "Hubble just found water vapor on an exoplanet, in a habitable zone, what does that mean for other planets?" - So recently some scientists actually discovered water vapor in the atmosphere of this planet. We now have over four thousand planets around other stars that have been detected, a lot of them are very large, so we're not really thinking about those as sort of Earth 2.0. a place where we could go to look for life. But the intriguing thing is, we're pretty sure water is critical to life, life here on Earth evolved in the ocean so when we go out and look at planets around other stars, we're looking for that blue planet, that ocean planet like the Earth, so the fact that we found water vapor, was exciting but unfortunately not sufficient because habitability is a complicated thing. - Yeah, so found water here, a water vapor but, there's many questions we have about for example: Do these planets magnetic protections layers like our Earth? Is the surface actually solid, or would you just sink in? Like if something is a gaseous type of planet, there's many, many questions so we're just at the beginning of that journey. - That's right and when you look at our own solar system, obviously the earth is habitable, it's been habitable for hundred of millions of years, and yet if you look at Venus or Mars, Mars was habitable for a very small portion of its history and a lot of us feel strongly that there could be evidence of past life on Mars. Venus was maybe habitable for a very short time in its history and as early in Earth's history, this planet was not habitable and as our solar system evolves, Earth will become no longer habitable so you have to think of habitability as not just a condition but actually a phase that a planet could potentially go through. - What we have done with the exoplanets is we've, using Kepler, looked at one part of the sky and just stared at it. And from that we managed to do a tally of exoplanets, so we know that for every star at least, there's one exoplanet out there, most of those exoplanets live in systems just like we do. There's other planets in our solar system, what we're now doing with TESS is we're looking at the entire sky, to really find the closest such things to investigate and like you said, there's very little we know about this. It's very critical to be able to follow up with telescopes like this one, the Hubble Space Telescope but also James Webb that's coming out in just a couple of years out there. - We're incredibly excited about the James Webb telescope because if you think of TESS, Kepler, Hubble, finding these exoplanets and getting a little bit of information, James Webb is really gonna be able to takes us to the next level. - What's really amazing about Webb, is when Webb was conceived early on, exoplanets were kind of a side story. Right now, it's one of the key stories because we discovered this abundance of exoplanets and we have an abundance of questions, many, many questions that we didn't know how to ask before. - So what the Webb telescope can do, is it can look at much higher resolution of the atmospheres of some of these planets around other stars. Not just looking for water vapor, but also gasses like carbon dioxide, methane and it's these combinations of gasses that we're looking for. The presence of water vapor isn't sufficient for life, but if you see a mixture of gasses and especially if those gasses seem to be out of equilibrium, or there's something causing an imbalance in the gasses, chemically and the atmosphere, that starts to make us think, not only could that planet be habitable, but is it actually inhabited. When I started out as a planetary scientist, you know, there were nine planets and then because of the declassification of Pluto we went down to eight, but for kids who are students now, by the time they're ready to become planetary scientists, which of course they're all gonna do, they are gonna be thousands of planets for them to study. And we got another questions on E.Z. Science it's asking about TESS, "What is the transiting exo-planet survey satellite? How does that actually work?" - What the TESS mission is doing, it's looking in a large part of the sky and it's staring at it and as it's staring, it's looking at the stability of light, so every once in a while, one of those exoplanets is going right in front of the star that it's around, and when it does so it every so faintly, reduces the light of that star, creating a transient feature and so that's what we're observing for all those stars, in that part of the sky that TESS is looking at. - And we can then use, how the light has dimmed to say what's the size of that planet, what kind of orbit it's in, which really helps us then start to nail down which of these planets are more like Earth, which ones are more like Jupiter, we're just about out of time, I'm sorry to say, thank you for joining us for another episode of E.Z. Science. - And please keep sending those questions, with hashtag 'E.Z. Science' so we can answer them at the next episode of - [Both] E.Z. Science!