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>> It's a great pleasure to have Professor all more shells visiting us today so how has a very exciting nontraditional career path the since she was at the age of 12 she was in very interested in answering the question whether we are alone in the universe a little she followed this path and out in her bachelor's degree at mit in the Department of Earth Atmospheric and Planetary Sciences and afterwards she was also very passionate in acting so she moved to Los Angeles and obtain a master's degree acting and also participated in a film called life line but 9 lives very exciting though she's still very interested in answering the question whether we are alone in the universe she went back to astronomy and she obtained ph d. degree in astronomy and astrophysics studying the interactions between planets and their stars and the effects on Planet climate and have the ability to afterwards she received you see presidents felt post-doc fellowship kind of work at u.c. Los Angeles and she also up trained in herself post-doc fellowship and work at Harvard and now how wise professor at u.c. Irvine does she is that expert have the ability and climate of exoplanets and she was selected as the happy if that low as well as that had fellow for her exciting work on the planet have the ability a rather low mass stars.

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So besides Don't Miss It was very passionate about encouraging young girls all state of that childish and though backgrounds to consider Korea sing us talk to me and she founded the nonprofit program starkers which company I once created very poorly theatre and create people arts with us talk to me based on her unique background though without further deal.

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Mike to our one who is share with us there just the people who are have to bow planet thank you so much John she threw that incredible introduction I'm really honored. And grateful to have been asked to speak here today although I know I'm not physically there with you in Georgia and here in Irvine California and I hope that I'll be able to translate my love of this field and the important implications for what we've studied in my group to you from.

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Thousands of miles away so let's get started before I jump into the science I want to invite those of you who are willing to take a moment to. Let me guide you through. 30 seconds of meditation mindfulness totally secular. We're going through some challenging times and I thought it might be nice to ground ourselves.

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So for those who would like to invite you to close your eyes sit back in your chairs if you're back great yet at the same time relaxed or like a mountain and let your and spread. On down tops of your thighs. Just start to tune into your breath this noticing whatever the quality units whether it's the or shallow is no same without judgment and notice where you can feel the breath most strongly whether it's the chest your lower abdomen or maybe the space right at the base of your nostrils despair for a moment now tapered States to the full breaths and perhaps the deepest breaths we've taken all day and through the nose side out through the mouth and once again in through the nose and out through the mouth and then let that go and just let your breath be natural perhaps since we are on a Monday if there's an intentional you'd like to set for yourself either professionally or personally for the week you can do that now just to yourself there's anything you'd like to focus on whether it's productive or restful restoring it.

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Hold bats lightly and then let that go trusting that your actions will be guided by that intention the things you choose to say yes to the things you choose to say no to will hold your intention as priority rather than the intentions or priorities of other people and finally notice something that you can be grateful for today and it could be something as simple as getting 8 hours of sleep last night or picking out your favorite chocolate bar at the grocery store.

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Or having that extra meeting that you weren't necessarily looking forward to and so whatever it is just add that in your mind's eye and carry that with you through the day there's always something and whatever situation there's usually always something we can be grateful for one more full deep breath and through the nose.

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And out through the mouth. We go your fingers and toes and when you're ready you can open your eyes as a little more than 30 seconds thank you for. Bearing with me those who are trillions in my fullness that's 5 you were able to do something else wrestle with that time and for those who like doing that I hope that you'll do more of that in the coming weeks and months as we continue to bravely.

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Show up for this unprecedented time and in our lives. But they also want to share. Is many of us on the call here today are leaders in some way and the leader leaders. Actually I've learned recently can be defined even more broadly than maybe a traditional managerial role but for those of you who are leaders in more richer Ishmail sense which is that you have which means that you have potentially employers that you supervise and want to share a few strategies that I recently discovered.

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Or leading effectively during the coding 19 and back. And so one of them is your employees leave your trust in your compassion and there are there are ways to be present even when you can't physically be in the room with them giving them direction and listening to their progress and many of you are already in floor employing these ways zoom bluejeans whatever online platform to regularly meet with your employees the kind of thinking outside the box ways to be present to be consistent whether it's an email check in on a weekly basis or reading some online or using some online platform like slack where employees can regularly interact with each other to sort of emulate the knocking on the door or to chat that we can't do right now.

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Some way to stay connected to check in with your employees is is critical right now employees need stability they need to know that their well being is a priority right now what I have found with the people that. I manage so to speak my post starts my students is that they have a lot of feelings understandably so as do I.

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And they may not necessarily have the same level of comforts that I do in terms of space and a whole means to to be able to. Feel free their space limited or maybe their space may be limited and they may not be able to go outside as often things like that and so encouraging them to do whatever is if in their power to do to prioritize their well being above.

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Actual work productivity is important and that's difficult. Because there are of course Bratton G.'s and things that need to be done and. Progress it needs to be made but right now all the danger of. Mental health issues is great and so making sure that employees know that taking care of himself physically emotionally mentally is more important than getting the paper out on time.

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Is important and I've had said to reckon with that myself and then employees need hope they need to know that this is not going to last forever that they're not going to be stuck in their dorm room for ever. That that there is something to look forward to when you can and we can do that as leaders by talking to them about our own purpose and values and what we can think up and see in the future as occurring in so sharing your own purpose your values things that you're looking for and see you professionally and maybe even personally if you feel comfortable gives them that hope allows them to see that there is a light at the end of the tunnel if you can see it maybe they can see it too.

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There's a website where I found there was a man in the website goes into more elaborate elaborates more about each of those 3 strategies. Ok though I know just by going to your website that you have a very broad range of disciplines within the field of physics represented in your department and so I thought it would be nice to start off with this little schematic so of course what I'm talking about are planets Gale astronomical phenomena but.

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Planet kind of sits right in between a proton and the and the observable universe so. This might give you some perspective for those of you might be atomic physicists. Says knowledge is is that says this is kind of pretty close to the halfway point between We're living in a whole new universe now.

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Far away from that initial discovery of the 1st planets or a mass companion orbiting another main sequence star and this was of course 51 Pegasi. Found in 1905 and this this planet. Was found to be. What about on the order of Jupiter Jupiter mass. And not Earth like by any standpoint and of course Myron equals one the Nobel Prize for this discovery we now know of over 4000 confirmed exoplanets as of this morning this is the number across a variety of regimes.

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But still this is the only planets that we know of support the conditions required for life whenever we have dozens of planets around orbiting other stars that may or may fit that bill these planets include planets in the Trappist one system. All 7 of which are in the Earth's size regime Proxima Centauri so a planet found orbiting the closest star system to us and l.h.s. 1140 the and many of the planets salute the explosion of planets detective really occurred as a result of NASA Kepler mission the transiting mission that sort of staring at one patch of sky and towards the constellation Cygnus and just took snapshots waiting for transiting planets planets to pass and friends of their host stars from our vantage point unlocking out a little bit of the light which allows us to determine the size of those planets since Kepler is has been retired we now have a new mission test the transiting exoplanet Survey Satellite which is an all Sky Survey and is expected to discover thousands of planets and these planets are going to be orbiting the closest stars to us the stars in the nearby solar neighborhood and this is great because it means that these planets will be much easier to follow up on with next generation instrumentation and so we've already discovered Earth sized planets as a result of tests so these are a few of them with Mars and the earth to scale and now we can add most recently t o y $700.00 to the list which is an Earth sized habitable zone planet recently found by Tess I think it was in January of this year that it was discovered.

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So these planets as I said will be much easier to follow up on to characterize them which means looking out there at these planets for the composition of their atmospheres or what we call bio signatures which might be which are biologically biologically induced global impacts to a planet's atmosphere and or surface that we could observe remotely and depending on who you ask this may be possible with chains well for certain planets but most likely will need a very large and these are truly next gen instrumentation such as the large u.v. optical i.r. surveyor and war and have x. And these are still in the mission concept phase but culturally at least one of them will fly alongside a spacecraft we will have extremely large extremely large telescopes E.L.T.'s on the ground along with other large ground based telescopes that will be useful in characterizing exoplanet atmospheres and possibly surfaces in the coming decades and this is all towards the goal of now we have been embarrassed when it reaches right now this dozens will be hundreds over the next 5 years of planets that lose support conditions for life we won't have infinite telescope time to follow up on each and every one of these planets so we'll need to prioritize those that have best chances of being habitable over the widest range of conditions.

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That a necessary for life and so we'll need to be able to prioritize which ones we select for those follow up characterization efforts. So usually the 1st step we take when we're going to look for a planet that could be habitable is to identify a planet that orbits its star in a particular region.

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In space and this region is known as the habitable zone to close in to the star and you notice here for those who are not astronomers on this call so we're going up and flat in stellar mass and. Cellar temperature is directly tied to the star's mass and so that's why your habitable zone goes in this direction so of the hotter brighter the star they're farther away or habitable zone needs to be in the same way that you need to be much further away from a campfire from a bonfire than you would a very small campfire to get the same amount of heat don't you post and so the star in the planet is in danger of losing its entire water in Tory to space in a runaway greenhouse state too far away and the maximum c o 2 greenhouse limit is reached that's the point beyond which any further increase and 02 would no longer be sufficient to keep temperatures above the freezing point of liquid water and these these boundaries assume an earth like atmosphere earth like climate that has intrinsic to it and active carbon at silicate cycle which regulates serum to with temperature and so that's something to know about how it will sell and that's one of the reasons why it's incredibly limited and only really is 0 for place to start when we're looking for have all planets that assume a lot about about these planets when we use the habitable zone is our only determinant.

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We of course know that many factors and affect planetary habitability and our planet is one major example we're very comfortably within our whole star's habitable zone and yet there is ample evidence geological ileo magnetic to suggest that we experience a significant climatic event 80600000000 years ago called snowball earth where the entire planet was covered in ice from pole to pole so liquid water is what we use as our.

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Criterion for habitability and that's because all planets all life on this planet requires liquid water or chemical bonding as a solvents for chemical reactions. So if we think about all the different parameters that affect the presence of liquid water on a planet's surface. It's quite complex quite fast so this web of factors.

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Can be overwhelming and so my team c.c. the shield center for exoplanet climate and interdisciplinary education has focused on several of these parameters over the last several years what I'm going to talk about today. Is surface composition and how important surface composition is. For climate and habitability when we approach climate modeling studies.

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The exoplanet community tends to assume that all planets are covered with ocean and there is a good reason for this assumption it's simple we have no idea yet what planet surface compositions are we don't know anything about ocean before mystery so we tend to assume that these are not only covered with ocean but that the ocean is like a slab of ocean maybe 50 meters deep there's no ocean it transports some studies have been incorporated full ocean circulation and 5000 meter deep oceans but those studies take a long time.

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And so it's it tends to be tends to allow us to cover a much broader parameter space if we assume slab ocean models and of course that we've got one surface composition and that's that's all that this these global climate models that we use. They have historically been used to predict climate and weather on the earth and they use a series they solve a series of spoiler in equations that govern conservation of momentum mass continuity conservation of energy and the equation of state for the atmosphere and so these models are still being used to predict future climate on the earth and have been used to assess and determine the extent of anthropogenic carbon dioxide induced climate change into the 2100 s. and they started to be used to look at past possible past States on earth like the snowball earth state that I mentioned.

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A couple of decades ago and so snowball earth. There is this conundrum if the planet was totally covered in ice how did life survive we have evidence that even photosynthetic life survived and how how could that be if its life was totally cut off from the sun by and one kilometer thick ice sheet for example and so other story an abbot and others have looked at possible refuge as scenarios like a water Gulf state which they call the Army band climate state where perhaps the entire planet was not completely covered with ice but that there was a narrow belt of water open water at the equator and they found that under certain conditions this this belt remains stable and climate model simulations is climate models have been applied to other solar system planets like Mars and again another mystery is.

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We have evidence that suggests that. Water once flowed on Mars we see the evidence of that and. Graphically and we see what looks like channels river channels Accenture. Hematite blueberries on Mars and we we know that there was no only form in the presence of water. And yet we know that Mars currently doesn't have any kind of an atmosphere so that can sustain water and terms of its pressure and so how how was early Mars warm enough to sustain liquid water so there's been a number of studies that have looked at that and identify scenarios.

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Such as pollution induced c o 2 absorption except for that have allowed. This the climate to want to and the climate to be sustainable of look at water on the surface. And then more recently we looked at exoplanets with these climate models and some of better early work looked at different scenarios for habitability and so it's very easy to think about having a planet looking just like the earth or not just having a similar feedback cycle like carbon and so it's cycle but also having It's a similar to partner feel similar.

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Orientation for ocean versus consonants but could you imagine a planet that was synchronously rotating where one side always faced the star of the other side it was always night and yet it had an eyeball open and a patch of open water right in that some still or point that remained open but the rest of the planet was frozen and this was the subject of some early work by by Ray pure Humbert and more recently I mean models have been used to.

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Postulate potential habitability scenarios for Proxima Centauri be one of the most exciting potentially have all planets discovered recently because it's so close to us and therefore So essentially characterize it all and then there's Starlight and this is where I've spent the greater part of my focus and that's how light from a star interacts with the planet's surface how that interaction and affect the planet's climate and habitability and one of the 1st surface types I started with was water ice.

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So I saw beetle feedback is a positive feedback on our planet we think the ice has been very bright spinning very white and the more light that ice reflects the colder the planet gets more ice forms reflects more light temperatures get colder exception that's what we mean by a positive feedback process whenever I sell Beetle has a spectral dependence so the ice will be no feedback mechanism is going to be sensitive to the wavelength of light coming from the whole star water ice absorbs longer redder wavelength light and reflects shorter bluer light and so thinking about what this might mean for any 2 or planets is exciting So what I'm showing you here is a plot of the spectrum for different types of post stars.

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So again for those of you who are not astronomers in the audience so we've got the hottest star and this on this plot is an f. star so it's peak Lux is much. Much shorter wavelengths the hotter star and hotter stars have their peak flux and shorter wavelengths whereas the cooler stars emit their peak like that longer redder wavelengths So we have the sun here in the yellow.

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Star that's a little cooler than the sun like a star in orange and then the coolest star on the spot is and $35.00 star 80 Leo so. As I have just stated stars aren't the only objects that exhibit wavelength depending properties and this I saw you know feedback if we look at.

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This more quantitatively Now what I'm showing you is I'll let you know as a function of wavelength for ice of different grains sizes and I'll be doa again for those of you who may not be familiar with that term that's just reflectivity honest from 0 to $1.00 it's how reflective this surface is so if it's one and it reflects 100 percent of what a light that gets and if it's 0 it absorbs everything and so we've got.

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Ocean here which is very absorbing it has a very flat spectrum throughout this range. And so which is just fine grained ice the highest up you know surface type that I'm showing you here the lowest l.b.l. ice type is Blue Marine ice and so both of those and members you're seeing in the top right here on the picture that see war and so is a big ice guy University of Washington.