[Music] hey there i'm diana and you're watching physics girl last week NASA made this big announcement about a new planetary system we found with a star called Trappist one that has seven earth-like planets ah it's 39 light years away but that would still take some millions of years to get to its current technology so tough luck I'm visiting it but there are still some crazy things about this system the planets are all way closer to their star than even mercury is to our Sun there's a possibility some of them are habitable and the telescope that found them and the star are both named after a Belgian beer good stuff I got to interview one of the scientists on the team who was also my first freshman physics professor at MIT and I had a quick Skype chat with another scientist on the team I asked them all about this discovery is it is it exciting no well it's sort of okay no it's super exciting of course is exciting it's an amazing like discovery and Travis was trending on Facebook yeah yeah I was reciting they kept getting like messages for my friends during the day like oh it showed up here you know I would get in the car with like uber driver and like baby Halley like oh what are you doing I'm like oh can hear about the apprentice and they're like oh yeah the most amazing thing is like i was on discovered like can I get your picture you are over driving exactly you're looking once you hit that level the most important question what have we discovered so we found seven earth sized planets around a nearby star and the seven planets are a space pretty evenly away from the star and three of them are kind of right in the middle where we think that water could possibly exist on their surfaces so we actually wrote a paper last year reporting the discovery of three planets around the system right and then in December of 2015 one of my colleagues got a transit with the very large telescope in Chile and the transit was really bonkers so usually when we see a transit we kind of see like a little dip and then kind of comes back up very normal this was like this kind of wonky up-and-down and it is initially we just like something that's wrong with our calibration or something like that one of our teammates kind of realized that is that this is actually the transit of multiple planets passing in front of the star and at the time we didn't had actually found those three classes yet right so we were like wow something is so there's there's some there's other stuff going on here yeah but if one thing that I've heard and like but I haven't heard a lot that people are like we've discovered so many exoplanets lately like what is so exciting about this perennial so a few things so obviously the fact that they're all earth size is very new right so up to this point most of the planets we find kind of from our various techniques have usually been big gas giants of course we've never seen this many planets around another star and we've definitely never seen this many earth sized planets around our star I mean not even around our star right we got four that's it so this is already set to state one of the big questions we're trying to ask all of us sort of an astronomy is are we alone in the universe like how did we get here is life unique to this planet like what does it all mean and this is like does it mean more right yeah is life elsewhere in the universe and you know one of the things we know in terms of ingredients for life on this planet is the fact that has liquid water right nowhere else in the solar system as far as we know has looked at water on its surface today we found lots of planets that are huge planets Jupiter sized planets those are probably just big gas balls and not great places to stand around and so that's why the sizes are important and then of course the distances are important because they tell us how much heat they're getting from their star and whether they have liquid water on them you know the same way that people study galaxies or stars planets are these planetary systems are these very interesting dynamical systems and we want to know just like we won't know how galaxies form and how the universe form that how stars form we want to know how planets form and you know we can look at all the different types of stars and understand something about their evolution and I for me it was very interesting just seeing about planetary systems as sort of this new class of objects I don't know how in several this question is for a film going to 42:46 purposes I want to ask about like what it would potentially be like living on this planet that's going to kind of depend on whether their Title II locked so the first thing one of these find out is there's an atmosphere and we can do that because when so the way we should go back away we found these planets is that they pass in front of their star and they block out a tiny tiny little bit of like yo you can get a little demo alright great so here's a sparkly little Trappist one linking in its redness and here's one of the planets passing in front watch it carefully that was very exciting okay so yeah and it blocks about that much light which is about 1% of the light from Travis one tiny little signal so that's how we find the planet now some of that light if there's an atmosphere also kind of filters around the planet and through the atmosphere so molecules in the atmosphere will interact slightly differently with different colors of starlight and so if you look at the light coming through the atmosphere when the finest in transit you can start to probe what molecules are in the atmosphere I'm surprised if isn't it possible why you've got so much light coming from the Sun from the star and then the amount of light that is going through the atmosphere is tiny a tiny high when I did the planets patch them in the star that's a 1% effect when we measure the light going through the atmosphere it's like a parts per million measurement so it's a tiny little signal so the next step is really going to be studying the makeup of the atmospheres using the absorption of light duty atmospheres so that's going to be huge and really probably can be done with JWST which the James Webb Space Telescope which actually hasn't launched yet and does that long tonight it'll be next year I don't know exactly when but yeah it's looking at your sometimes those are really excited at what level are we at with our knowledge about the composition of these planets yet we can say that we think that they're rocky with some atmosphere or primarily rocky with atmosphere though we're not at the point yet where we can say how much atmosphere there is so there's two problems one is that there's seven planets so that pull is like oh well back and forth is a crazy way so the planners are interacting with each other as well yes in this system what's different is the planets are near what called me motion resonances so these are where these are sort of special orbitals locations where the period of two planet forms an integer ratio is like a in a car when the one in front of you is you know maybe blinking twice every time you're in blinks ones and you know they meet up every once in a while a ones way around twice every time one goes or I can't do that because the I don't oh yeah and when you're in configurations like that you can end up where basically the small gravitational sort of kicks to the planet gave each other they end up sort of meeting each other at the right time in their orbit so that those kicks add up coherent ly if you like if you're pushing someone on the Queen every time the person's back that's when you push them so your your pushes add up and the person starts screaming more and more that does not happen in our lord system it does happen in our solar system with the moons of Jupiter right those Jupiter's moons are very close together so what the result of that is that the IO is in this funny configuration where it gets kind of yanked into a slightly eccentric orbit and then Jupiter tries and yank it back into a circular orbit and I'll get yanked back and forth yeah that yanking causes it to stretch and that stretching causes it to become volcanic ah it heats up from the inside Wow yeah these planets are also in pretty close residence and that's why we see these time in terms of time and variation and yeah planetary systems are complicated how much do we know about like what it would eventually be like to live on money I think this is a question for like science fiction writers they can chew on for many many years however curious or accuse Amyas so once the one factor is that they are so close to their Sun or their star that they are probably tightly locked just like the moon is tidally locked to the earth and so that has a couple of interesting effects right the one is what kind of it that's exactly the response he would have in one of these planets because nothing would change right you wouldn't have the Sun rising and setting they would just stay there right and if you're in the dayside you wouldn't even see the stars I mean there's many cycles in our bodies that are based on the cycles in the earth right we wake up and we fall asleep cycles that are based on the day and night we have menstrual cycles that are tied to the moon maybe there's a moon so that would be that would say if you'd haven't given you kind of know what time this right now imagine you have a world that has no external triggers you know indicators of time passing how does life evolve to fall into these cycles right so actually once the one cycle they will see is very migrated I'm sorry so the good thing about these plants being so close is that you can see them right so even if you don't have a moon you know you're standing on trap is one see you're going to see trap is one be kind of swing around every day and a half and so that gives you kind of a trap this one be o'clock or hey and then so these plants are really close together yes yeah super close to their star and in fact if you compare the size of this system to the size of Jupiter and its moons would you talk about before that's actually pretty close I kind of talked about the authority that's what we're what we're looking for next so we're looking for an atmosphere the opposition the atmosphere you can think about it as sort of a process of characterization where from the transit we find the planets we know what their periods are and learn about how big they are more transits are going to help us measure masses so then we can might be a rough idea of composition if they're rocky or not and then ultimately we know we want to say a few one of the atmosphere is made out of and that's still to come we're now starting the speculoos survey we chose about 500 very low mass stars all within the vicinity of the Sun and what we're going to do in this survey is actually image all of them with and do the same kind of measurements for every one of these stars and the goal is to actually answer the question is this a unique system or is this actually quite common I just imagining like picking up a piece of dust with the tweezers off of your and being like okay I'm going to learn all about the outer layer of it by just like you know sending a flashlight from over there yeah that's exactly so yeah it's really cool amazing we can play all this stuff down has man astrophysicist are the best thank you so much for hanging out while I grilled these scientists with my curiosity let me know in the comments if there's something you're really excited about with regards to exoplanets and happy physics thing [Music]