Is There Life Beyond Earth? / Seminar Day, Session IV

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Summary

The Caltech seminar "Is There Life Beyond Earth?" explores the intriguing possibility and scientific pursuit of finding life outside Earth. The session, moderated by Mike Brown, involves prominent planetary scientists Heather Knudsen, Woody Fischer, and Kevin Hand. They discuss the challenges of discovering "Earth-like" planets, the potential for life on Mars and icy moons like Europa, and the various scientific methods used in these explorations. The seminar delves into the hurdles and excitement of current and future missions in understanding life's origin and prevalence beyond Earth, culminating in an engaging discussion of the philosophical and scientific implications of discovering extraterrestrial life.

Highlights

The seminar explores the possibility of life beyond Earth with expert insights. 🌍
Exoplanets are a major focus, but identifying true 'Earth-like' conditions is complex. 🔍
Moons such as Europa might harbor life due to underwater oceans. 🌊
Mars exploration continues, offering insights into past habitability. 🪐
Future space missions and advanced technology are key to potential discoveries. 🚀

Key Takeaways

Life beyond Earth remains a captivating mystery awaiting exploration and discovery. 🌌
Exoplanets are key targets, but defining 'Earth-like' remains challenging due to limited data. 🪐
Moons like Europa hold potential due to their hidden, possibly life-sustaining oceans. 🌊
Future missions and technology are crucial in the quest for extraterrestrial life. 🚀
Discovering life would revolutionize our understanding of biology and place in the universe. 🌌

Overview

In a riveting session held by Caltech, scientists and experts gathered to discuss the tantalizing possibility of life beyond Earth. The seminar, led by Mike Brown and featuring panelists Heather Knudsen, Woody Fischer, and Kevin Hand, dived deep into the mysteries of the cosmos. They explored the scientific methodologies and the current excitement surrounding the discovery of exoplanets and what makes a planet 'Earth-like,' although this remains a challenging definition due to sparse data available for planets outside our solar system.

Mars and the icy moons of our solar system, such as Europa, were central in the discussions for their potential to support life. While Mars continues to be examined for signs of past life, Europa's vast, hidden oceans offer a unique environment that might be home to extremophiles—organisms that thrive in extreme conditions on Earth. The session highlighted the importance of ongoing and future missions to uncover these cosmic secrets.

As scientists strive to understand the universe and our place within it, the discovery of life beyond Earth would not only be scientifically groundbreaking but would hold profound philosophical implications. It challenges our perceptions and understanding of biology, evolution, and the uniqueness of life as we know it. The pursuit of these answers continues to drive research and innovation in space exploration, reflecting humanity's deep-seated curiosity and the desire to know if we are alone in the universe.

Chapters

00:00 - 00:30: Introduction to the Panel and Moderator (Mike Brown) This chapter serves as an introduction to the panel and the moderator, Mike Brown. It sets the stage for a discussion that is both relevant to Caltech and explores the vast possibilities of life beyond Earth and our solar system. Mike Brown's qualifications are briefly introduced; he's the Richard and Barbara Rosenberg Professor of Planetary Astronomy and directs the Caltech Center for Comparative Studies.
00:30 - 05:00: Introduction to Panelists: Kevin Hand, Heather Knudsen, Woody Fischer The chapter introduces the panelists: Kevin Hand, Heather Knudsen, and Woody Fischer. It briefly focuses on one panelist, a passionate figure in comparative planetary evolution. He is known for his unique Twitter handle "pluto killer"—a blend of his work in astrophysics and a nod to a WWF wrestling persona. Hailing from Huntsville, Alabama, the site of the Marshall Space Flight Center, his early exposure to space exploration sparked a keen interest in celestial bodies. Currently, he is engaged in the exciting search for the elusive 'Planet Nine'—a speculative giant planet predicted to exist beyond Pluto. The project, dubbed "Planet Nine from Near Space," is a primary topic of discussion. As a fascinating side note, one of the panelists has popularized this venture.
05:00 - 09:00: Discussion on Discovering Exoplanets and Earth-like Planets The chapter begins with a reference to the advancements in exoplanet meteorology, highlighting the achievements of an individual listed among the world's ten most brilliant scientists. This signifies progress in understanding planetary atmospheres beyond Earth.
09:00 - 18:00: Challenges in Exoplanet Atmosphere Analysis The chapter discusses the fascinating challenges and advancements in the field of exoplanet atmosphere analysis. It opens by referencing a book by Kevin Hand, highlighting the revolutionary progress made in understanding that physics applies beyond Earth. This sets the stage for deeper exploration into how physics can be used to comprehend solar system phenomena, extending its application to the study of exoplanets.
18:00 - 29:00: Mars and Europa: Potential for Life in the Solar System The chapter discusses the universal application of chemistry and geology beyond Earth, with evidence of the same chemicals appearing in stars and other planets. It also mentions the functionality of aeronautics on Mars, emphasizing that many principles known on Earth are applicable elsewhere in the universe.
29:00 - 43:00: Biology beyond Earth and the Origin of Life The chapter explores the possibility of biology existing beyond Earth. It questions whether biological processes are unique to Earth or if they could occur elsewhere in the universe. This topic will be discussed with insights from three panelists, starting with Heather Knudsen.
43:00 - 55:00: Potential for Life on Mars and Europa The chapter begins with an introduction to Heather, a professor of planetary science at Caltech, known for her work as the first exoplanet meteorologist. The close proximity of her office to the speaker's is noted, which facilitated frequent informal discussions. Heather's expertise lies in the study of planets beyond our solar system, focusing on how to locate them and what discoveries in the field we might anticipate in the future. Additionally, the panel includes Woody Fisher, another esteemed professor, though his specifics are not detailed in this excerpt.
55:00 - 76:00: Exploring Exoplanets and the Likelihood of Life in the Universe The chapter focuses on the exploration of exoplanets and the search for life in the universe. It highlights how the study of geobiology, which examines the evolution of life on Earth, can be expanded to explore the possibility of life beyond our planet. The chapter also discusses the work of scientists like Kevin Hand from the Jet Propulsion Laboratory (JPL), who is involved in efforts to land a spacecraft on Jupiter's icy moon Europa, a location of interest for its potential to support life.
76:00 - 102:00: Audience Questions and Answers The chapter titled 'Audience Questions and Answers' involves a panel discussion where the panelists are invited on stage to greet the audience. The conversation begins with an introduction from the moderator, who humorously acknowledges their rocky start, and proceeds to engage Heather, one of the panelists, with a question. The question is centered around the frequent news headlines about newly discovered planets, alluding to a broader discussion on this contemporary topic.
102:00 - 105:00: Final Words and Closing Remarks The chapter discusses the frequent announcements in media about the discovery of Earth-like planets within our galaxy. It raises the question of what scientists and headline writers mean when they term a planet as 'Earth-like'.

Is There Life Beyond Earth? / Seminar Day, Session IV Transcription

00:00 - 00:30 what we're going to be bringing you is something that is close to home for caltech but very much out there in space the panel is about whether there is life beyond this earth beyond our solar system and the moderator who i will introduce to you is mike brown he is the richard and barbara rosenberg professor of planetary astronomy and director of the caltech center for comparative
00:30 - 01:00 comparative planetary evolution but he also has as you may know the enviable twitter handle that sounds like a hybrid of astrophysicist and wwf champion pluto killer he grew up in huntsville alabama which is home of the marshall space flight center and that fired up his interest in space he is now hunting for planet nine a hypothesized giant planet hiding at the edge of the solar system so planet nine from near space is his project and here's another bonus nugget for this panel one of the panelists made popular
01:00 - 01:30 sciences list of the brilliant 10 as the world's first exoplanet meteorologist so in may future and maybe in the future telling elon musk the best weather window for landing his mars rocket so mike brown is uh ready to take it away mike thank you so much i just want to thank everybody for coming i'm excited to to be here and be able to tell you about these ideas from our panel about uh whether or not there's life beyond the earth and i want to start out by by thinking about this problem in a way
01:30 - 02:00 that's been i think really nicely laid out in a book from one of our panelists kevin hand who you'll get to meet here in a minute and and kevin uh really really started out saying which i thought was a really interesting way of doing it is is that we're in this we're in this interesting revolution we have gone through the stage where we have learned that physics works beyond the earth newton realized that you could you could use physics to understand what was going on in the solar system we now can use physics to understand uh
02:00 - 02:30 what's going on in the entire universe chemistry works beyond the earth we started seeing the same chemicals in the stars that we knew was on the earth we now see them on other planets geology geology works it's a little bit weird on other planets sometimes but it's the same geology that we see here we even know that aeronautics works on the earth or off the earth works on mars at least and so so all of these things we're showing are general things that work beyond just here on the earth one interesting question that we
02:30 - 03:00 don't yet know the answer to is does biology work beyond the earth and okay it's a sort of stupid question um of course biology works beyond the earth the question really is has biology ever worked beyond the earth or is it really just something that's unique here that's the question that we're going to be talking about today we're going to be talking about that with uh with three panelists so i'm excited to introduce now to uh the first is going to be heather knudsen
03:00 - 03:30 heather is a professor of planetary science and and back when we used to have offices at caltech i could knock on my wall and she would be right next door to me and and uh we could just uh chat all the time she's gonna she's the one who pat hinted uh what is the first exoplanet meteorologist she will be talking about uh planets beyond our solar system and how to find them and what we're going to be finding in the future also on our panel is uh is is woody fisher woody is a professor of
03:30 - 04:00 geobiology and as part of geobiology he studies the evolution of life on earth how it happens what's required to make it happen and how to expand those ideas um outward into the solar system and finally we have kevin hand who i mentioned earlier who is a scientist at jpl who amongst many other interesting things that he's done uh one of them is he is he is working hard to try to get a lander on the surface of jupiter's icy moon europa and we're gonna talk a lot about
04:00 - 04:30 that and i'd like the panelists uh to now come on stage and uh greet us all hi everybody i i hope um all of you work better than me i'm sorry that that was a little bit rocky at the beginning and uh i want to start this conversation um with heather a question for heather which is that you know all of us uh open up our favorite news sites these days and and you can't you seems like every week you read about some new planet that's been discovered around a
04:30 - 05:00 different star somewhere in our galaxy and uh we we often get these these breathless headlines that there's some planets that's been found that's the most earth like yet or several times a month the first earth like or something like that and so one of the first questions i want to ask is what what do astronomers mean or or headline writers mean when they say we've just discovered an earth-like planet yeah um so i think the number one thing
05:00 - 05:30 you should know about extrasolar planets is that we don't know very much about them so we're good at finding them we can measure their radii we can sometimes measure their masses if we're lucky we have a spectrum so when we say a planet is earth-like that is based on very limited information so mostly what we mean is that it's something that's the size of earth maybe we know that it's mostly rocky like the earth and usually it means that it's about the
05:30 - 06:00 right distance from its star to get about the same amount of light as earth but that doesn't tell us anything about whether it has an atmosphere what it's like on the surface all the really important stuff so so uh how do we learn those things about planets that's a even though it seems limited that's a lot of information for something really far away yeah well this is i think one of the nifty tricks uh that scientists come up with is that so the challenge here is that uh even the closest stars to the sun are
06:00 - 06:30 very far away and um planets are very tiny and very dim compared to their host stars so the trick of how to find planets around other stars was kind of a very technically challenging one fortunately uh there's a technique which has been very successful in finding planets and that is the transit technique so we wait until the planet goes and see if you can see this so um here's our star here's a tiny dot of a planet next to it um it's really hard to take a picture
06:30 - 07:00 where you can see that planet next to the star but if the planet passes in front of the star it's going to block part of the star's light so you don't see that because my star is not there yet so the planet will block part of the star's light and we can actually see that dimming in brightness and so that's actually the way we found most of the planets around other stars so that we know of something like maybe 5 000 planets around nearby stars which is a huge accomplishment
07:00 - 07:30 many of those planets look very different than the earth does so although you mentioned we celebrate every time we find one that seems kind of earth-like the majority of planets we find are bigger hotter and generally quite diverse compared to the planets in the solar system so what what what what is your uh your favorite planet that is the most earth-like i i think we don't really know enough to say if any of the planets we found are
07:30 - 08:00 actually earth-like um we don't we haven't detected an atmosphere for a planet that is earth-sized so we're only guessing about whether or not any of the planets that we found so far might have an earth-like atmosphere uh but i think the most interesting ones we've found so far actually um are interesting because they orbit very small very dim stars uh so the planet even though it orbits with a period of just a few days it actually still gets the same amount of light
08:00 - 08:30 from its stars so so a period of just a few days i mean it has it's year its year is just a few days long exactly because these stars are very small and dim so to be the same temperature as the earth you have to move the planet much much closer to the star and so that sounds kind of different but um it turns out those if we want to actually detect the atmosphere of an earth-like planet those are the kinds of systems that are easiest to study so those the ones that we're hoping to observe with the james webb space telescope which is the next big space telescope launching later this year
08:30 - 09:00 okay so let me let me bring in woody here for a second because uh so it's as much as we get these excited headlines that you know new earth-like planet discovered as as you're saying it's it's our real information is is pretty limited woody as someone who discovers uh who studies um an earth-like planet which is actually the earth um what do you see as like if you were if you were an astronomer or you could you know tell astronomers what
09:00 - 09:30 to do regardless of what the technology says what would you want to see in a planet that you thought might be not just capable of supporting life but but starting to have life these days yeah absolutely mike you know we get we get answers to this question from studying all kinds of environments today and of course if you were just limited to plants and animals you might have the impression that habitability is actually kind of bespoke but what we realized from studying microbial life today on earth and in the past is that there
09:30 - 10:00 are actually a number of dimensions important dimensions to habitability water that is liquid water that is stable on the surface of the planet and long-lived uh there has to be a source of energy to be able to run the cells that are going to comprise uh comprise the biosphere that for earth that source of energy is all redox reactions life is very much electrical in that sense um there also needs to be the presence of elements that we think are critical for um biology and that means carbon
10:00 - 10:30 and hydrogen and oxygen and sulfur and phosphorus and then a small catalog of trace metals that we don't talk about as much but that are also very important to get life to run um so it might seem like kind of a detailed list although one of the cool things that we learn about studying microbial life on earth is that actually there's a huge spectrum in different dimensions that depict habitability for example life can live well above the boiling point of water up
10:30 - 11:00 to almost 150 degrees c and well about well below the freezing point of water maybe down to minus 25 degrees c life can live in fluids that are very high ph alkaline 12 ph of 12 we're down to very acidic fluids like a ph of minus one so we know that there are these huge limit uh you know the the habitability you know you know we've there's tons of of kind of habitable volume on our planet that extends far beyond
11:00 - 11:30 what you think of when you just think of animals and plants so but so the even though the conditions you mentioned are are pretty extreme they do all have that one basic thing in common which is liquid water is that is that yes so so astronomers aren't crazy it's good to know um for uh emphasizing liquid water um heather these these other things that uh that what he talks about the the different
11:30 - 12:00 other elements that are in there what what are our prospects in the future for knowing knowing what's in an atmosphere for knowing what else a planet is made out of besides just knowing hey it's at about the right temperature if there were water it could be liquid yeah so i think it all comes down to the atmosphere right so the atmosphere sets the stage for life it determines the conditions on the surface whether or not you actually get that liquid water but also the atmosphere can be a sort of repository for materials
12:00 - 12:30 produced by life so if you have little bacteria kind of covering the surface of your planet they're taking in gases they're releasing gases and so they can alter the composition of the atmosphere merely by being there and so that might be something that we could detect so we don't know what the what's inside the planet we can't see what's on the surface but we can inventory the gases in the atmosphere of the planet and we can ask whether there are gases that don't belong
12:30 - 13:00 so gases that if it was just geology volcanoes oceans you know clouds that we wouldn't expect to see those gases in the atmosphere so that would be a way to indirectly infer the presence of life even very simple life so and you know i i can see woody just itching to go in and to mention that maybe this has happened on the earth at some point um what what what what are you itching to say there woody oh i'll just i'll just tell you um it's dioxygen
13:00 - 13:30 in the empty atmosphere i mean that that's the big one right i mean the reason we have something to breathe ultimately owes itself to the this photosynthetic process this innovation that happened long ago filled our atmosphere with dioxygen and and wow you know our planet didn't look that way for half of its history so it's very much a biological innovation that that you know that gave us a fifth of the atmosphere um is dioxygen in the atmosphere and that that's a that's a huge huge uh environmental change and
13:30 - 14:00 it's a huge huge um evolutionary kind of revolution that takes place around oxygen very excited about that i'm going to push on you on that because the um uh and we'll get to europa in a minute but the um as you know europa has got a very thought i'm going to stop you we're going to get to europa you got to just wait but oxygen in the atmosphere is not quite enough it's uh it so it's a i i think that uh it's a good debate and let's let's definitely have
14:00 - 14:30 this one so but the it's an interesting point is that um well these points good one oxygen in our atmosphere is caused by biology um but it might not be enough so let me get back to heather like so what what are do astronomers have any ideas on on how to look at these gases and say uh this is this really is something unusual that we should look at on are there other prospects or are we going to be left
14:30 - 15:00 uh arguing the entire time which which is what scientists really do best we may be left arguing forever just because we like it and that's okay um but yeah you'll notice i was careful not to just say astronomers are searching for oxygen on other planets because it's not quite that simple i so going back to you asked me what my favorite planet was and i realized i never named it so let me tell you the name of the system is trappist-1 it's named after a beer right here it turns out but um it's a system of seven planets
15:00 - 15:30 that go around a very small star and if you model what the atmospheres of those planets might look like an obvious guess might be that some of them have atmospheres that are rich in carbon dioxide like venus and mars and if you take that planet like the earth early on that's also true so take that planet and put it around this dim cool star with a lot of ultraviolet and x-ray light and you make diatomic oxygen you make lots of it without ever having to have life on the planet so we have to know what else is in the
15:30 - 16:00 atmosphere and know what reactions are happening in order to understand what doesn't belong if it's oxygen or something else that we should be looking at so so it's hard and uh what if you if you look forward uh not just you you mentioned james webb space telescope which fingers crossed will be launched sometime soon um what's next what's what are the prospects even further down the road for for being able to answer these questions with with more detail
16:00 - 16:30 yeah so the way that we will do it with james webb is we'll keep looking at these eclipsing planets so planets that go in front of their star and will try to detect the starlight passing through the limb of the planet's atmosphere and to look for absorption from gases that are in the planet's atmosphere that kind of works it's still very hard it's on the limit of what james webb can do for small earth-like planets but um it is easily foiled um if the planet has
16:30 - 17:00 clouds and we know lots and lots of planets have clouds that can mask that signature that we're trying to see so the other sort of path that astronomers are pursuing is to try and take a picture of the planet sort of separate from the star and that's really really hard and we're getting better at it but to do it for an earth um even around a small star we'll probably take a much bigger telescope than we have right now so something like a 30 meter telescope which we're planning to build
17:00 - 17:30 could possibly do this so just for for scale that star and planet that you had that was probably about the scale of jupiter in the sun is that is that close to what that scale is uh actually i think this should be earth in the sun is that really the earth okay yeah yeah how hard could it be it's much easier because my star is not nearly as bright as a real star yeah so a better analogy would be if you imagine a spotlight with a firefly next to it okay so i want to i want to i want to
17:30 - 18:00 bring us back um uh to the solar system here a little bit and you know so we've talked about about uh about oxygen maybe oxygen is is a good thing to look for maybe not water liquid water um we have a rover uh that has just landed on mars who's whose job it is to look for signs of of potential microbial life that existed in the past i mean but come on mars is a pretty crummy place it doesn't have much in the way of liquid water if ever
18:00 - 18:30 it has uh frigid temperatures you're irradiated the surface woody why the heck mars it seems it seems pretty unlikely that uh mars fits any of these definitions of earth like or somewhere we would have microbes or something yeah that's one of the most interesting things you to look at mars today and and think hopeful thoughts about life is you know you've got to stretch your imagination there but one of the most interesting things i think one of the most interesting discoveries
18:30 - 19:00 in the last couple decades is the recognition that um mars has a geologic record it has a sedimentary record so we're not just limited to asking about what it looks like today we can ask questions about what it looked like in the past and when you start probing that record like the the two rovers are on on mars right now uh msl and mars 2020 um there's water all over the place there are rivers there are large you know really impressive deep rivers that are
19:00 - 19:30 empty into lakes and basins that we know don't have particularly exotic chemistry from the best we can tell they appear to be habitable and now so the question is were they inhabited so uh where did all that water go it's a great question there it you know with a question like that you you have a catalog of hypotheses um to draw from but probably the most popular is that it was lost to space it was it was lost through uh an escape
19:30 - 20:00 process of both hydrogen and and oxygen lost to space so so uh we'll get back to the question of of why just because it has uh had some early early water why it might have wet whether it really would have had life or not have life but but i wanna i wanna focus a little bit on this water and and um get to a question that kevin wanted to uh jump in on we're finally gonna get to kevin let him jump in on this one so we talk about water we
20:00 - 20:30 talk about water on planets around uh other stars in the galaxy we talk about how important water was here on the earth we talked about well maybe mars used to have water on it as as kevin will tell you there are places in our solar system with more liquid water even than the earth has on these some of these icy moons around these giant planets so the first obvious question that this bag's kevin is that uh uh great water is great it's
20:30 - 21:00 a great it's great to have water that means that we're interested in going to search of life there but but hold on a second an icy moon having uh a liquid ocean sounds pretty crazy right you go so we're we're talking here let's say about europa the big icy moon of of jupiter you look at its surface it's it's got things that are looks like big cracks in the ice crevasses it's it's uh it's super cold everything is frozen
21:00 - 21:30 liquid water doesn't very much look like liquid water to me so why would a place like this have all this liquid water kevin yeah so the um a couple of quick things to appreciate about europa and for that matter saturn's moon enceladus which we think also has a a large global subsurface liquid water ocean first is that um sort of counter to popular evidence earth is a bad place for life
21:30 - 22:00 but that is a bold statement so when when we look at the the evolution of our solar system the inner planets mercury venus earth even mars kind of got baked out in the relatively dry rocky planets but in the outer solar system it was cold enough for volatiles such as water to freeze out and condense and so europa is about six percent by mass water okay well that's water in either
22:00 - 22:30 ice phase or liquid et cetera how do we know that there's actually an ocean can i interrupt just because i actually don't know the answers what's what is what is the earth by mass of water it sort of depends how hydrated you figure the mantle is but it's something like less than one percent if you include the entire ocean that what he probably knows better than i do he's nodding we'll take it as one percent that's a that's a big thumbs up kevin so so then the question becomes um
22:30 - 23:00 what heather has described with the exoplanets that is what we kind of consider as the uh the traditional habitable zone you've got a planet at just the right distance from its parent star wait wait wait i'm going to interrupt you for a second because because i because i really want to get to this not the question of habitability yet i want to know why there's water it's all supposed to be frozen yeah yeah so traditional habitable zone okay you're getting liquid water from your parent star on the outer solar system there's this kind of new goldilocks scenario for
23:00 - 23:30 for habitability where the energy for maintaining and sustaining liquid water comes not from your parents star but rather from tidal energy uh dissipation that mechanical tug and pull that a moon like europa feels as it goes around jupiter and that's just kind of like you know if you take a paperclip and bend it a bunch of times eventually the paper clip will get hot well europa in its interior gets hot and that internal energy then helps
23:30 - 24:00 maintain liquid water as an ocean on europa can i just say so europa gets hot because because of the time what's bending it why is it bending because of light of the tides that are that are stretching europa so europa's got a slightly eccentric orbit a slightly elliptical orbit and jupiter's got this incredible gravitational field and as europa moves around jupiter it's stretched
24:00 - 24:30 differentially such that it's that the tides on europa so if you could stand on europa you might rise and fall as much as 100 feet in a given european day which is three and a half 3.55 earth days but that's that's not enough because there's one beautiful little quirk of our universe that actually allows liquid water oceans to exist beneath these icy
24:30 - 25:00 surfaces and that is that ice floats so so ice has a density of 0.917 grams per cubic centimeter whereas liquid water is one gram per cubic centimeter if ice did not float then even with that internal heat coming from tidal energy dissipation even with that heat uh you would uh you would lose the water you wouldn't form that nice icy shell that that serves as a blanket to insulate the
25:00 - 25:30 ocean within so that's that's a um it's a pretty interesting thing about ice ice ice is a weird mineral um this reminds me of a a final exam question on my thermodynamics as an undergraduate which is which is why do the properties of ice make it so that you can ice skate and the answer was supposed to be that when you press on ice it actually melts and it makes it glide but somebody wrote exactly what you said which is that if ice didn't float you couldn't ice skate
25:30 - 26:00 which i thought was a pretty good answer um so it's a uh that that's that's a pretty good reason for having a lot of liquid water there it started out with a region that was colder so it trapped a lot more water clearly has a lot more water there too but okay so europa has this shell that's that's miles and miles miles thick this icy shell and then there's an ocean down beneath it um how could there be life down there
26:00 - 26:30 well woody touched on this earlier and and uh when we think about oxygen of course that's tied to photosynthesis in an ice-covered ocean you're going to be cut off from sunlight so photosynthesis is not going to be an option but chemosynthesis life powered off of the chemistry of seafloor could help drive life and we can come back to some of the oxygen later but there's also a mechanism for delivering oxygen to the ocean but
26:30 - 27:00 woody you know what what are your thoughts on the viability of let's put it this way not just the habitability you know the the viability of chemosynthetic pathways within europa's ocean but also the origin of life itself because really when we talk about the search for life elsewhere it is about this question of whether or not the origin of life is easy or hard the origin of life is easy life is everywhere the origin
27:00 - 27:30 potentially uh if the origin of life is hard then we might be the only example of that we might be some sort of biological singularity yeah i think that's a really really good way of putting it um kevin the the thing that's probably so interesting is that um you know the origin of life science has received a lot of attention over the last decades it's a it's an absolutely hot topic and there's a lot of really great experimental work being done to try to understand it that said there's still places
27:30 - 28:00 in understanding life's origins on earth where we kind of wave a magic wand i go like this and then life happens but each year we have to do less wand waving as we get a chance to fill in more things and ideally what i think is going to emerge is um hopefully we understand how life arose on earth but that we understand more broadly perhaps there's a catalog of different ways that might lead to life earth maybe has one of them or maybe even a couple of them um and and ideally we can have a catalog
28:00 - 28:30 of a couple of different things that then we can say these processes are important these materials are important and then we can use that to say are these materials present in a europan case are these materials present if we look outside the solar system how likely are they to be on rocky planets uh how those kinds of things so i i think it's really i think it's the the answers to that are not far off the answers to those questions and there's a really interesting compare and contrast where uh this the sort of bifurcation in the origin of life is
28:30 - 29:00 could it occur within hydrothermal vents at the bottom of our ocean or could it occur in tide pools on the shores of earth's ancient ocean both of those modes are viable for ancient earth uh mars if life originated on mars it potentially would have been ancient tide pools and the seashores but europa really only has one viable way for the origin of life i'll put an asterisk by that but um that
29:00 - 29:30 would be the hydrothermal vent origin of life and so when we go out and potentially explore these worlds we are able to potentially test hypotheses for the origin of life itself and one nice thing about europa is that life could still be alive there today it's exciting all right well we're going to get to that here in a little bit um but i want to i want to i want to poke at this idea of life and uh life forming on europa and life foaming on mars
29:30 - 30:00 um with my first question on on europa so it's a it's an ocean that is uh it's dark not a not a not a drop of sunlight makes it through that uh that huge shell maybe there are hydrothermal vents at the bottom of the of the ocean um where the where the ocean meets the rock um maybe not we actually don't know that for sure but let's let's be optimistic and and say that there are but woody do you do are there examples on the earth is is
30:00 - 30:30 there any life on the earth that is that is currently extant uh that is 100 dissociated from sunlight um you know i people sometimes say oh there's stuff at the bottom of the hydrothermal vents i think all of those ultimately rely on food that comes dribbling down from the top are there places on the earth where there really is utterly independent from the sun yeah mike that's a really really good question because it's
30:30 - 31:00 it's a you think why do we not know that why do we not have a really firm answer to this question and it's because the impact of the kind of light driven biosphere is so strong oxygen makes it everywhere carbon makes it everywhere things you know the the earth's surface environments communicate with one another um you know there's mass transfer there's chemist chemistry that's that's taking place that said there are some candidates that you can find in exposed in mines deep in the earth's
31:00 - 31:30 crust where you can make a case a reasonable case although not a definitive one that though there are microbes that are there that have a chemosynthetic metabolism they're just using energy that's being made by the minerals that are present in that environment and the reaction of those minerals with water and and and and they are there they can hack it they could they can they can make a living now that said let me just add one more thing to that mic because the the light the way that light
31:30 - 32:00 comes into the biosphere is light energy is photosynthesis and photosynthesis is old but not as old as life itself so for sure there was an interval in the history of our planet when the biosphere was present but not yet photosynthetic and that is de facto a chemosynthetic biosphere we don't know much about it it happened long ago i think like four billion years ago um but it it's it it happened it did happen it is in the history
32:00 - 32:30 of of the biosphere on earth so so i mean in some ways you could you could say that's an uh that's an existence proof for something europa-like at least being viable if if that uh if that chemistry is active and we can get those right chemicals on there i want to i want to go back to something that kevin said um and poke at that too because we we didn't really talk as much about mars as uh as people often want to when talking about life um but kevin laid out these these ideas of
32:30 - 33:00 uh of maybe life originating in in tide pools maybe life originating at uh at sea floor events mars presumably did not have um the latter i i don't think mars would have had the former either i mean the the nice thing about tide pools one a critical requirement of tide pools is tides tide pools are interesting i think because they are wetting and drying and wetting and driving and that kind of drives the need for some sort of evolution
33:00 - 33:30 mars doesn't have a big moon mars doesn't have tides so uh what do people think about origin of potential life on mars what would drive it uh does does the lack of tides or or sea floor events matter uh or is this just things that we like stories we like to tell ourselves well i think it's those are really good questions there it's definitely stories we like to tell ourselves that's that's for sure but um
33:30 - 34:00 mars does have these environments that look you know these these look what we call the customer lake environments that underwent episodic drying drying and wetting they're closed basins and so the what depends on the water budget what's happening did it did it rain in the catchment that day or that year uh did it snow in that catchment the last ten thousand years and now it's melting and coming into we don't know a lot about the cadence though of what those the we know that those drying and wetting and drying events took place
34:00 - 34:30 but we don't know much about their their frequency well and what do you do is is the is the current rover you know what what do you think we're going to find in this current rover are we going to have answers to these questions are is this going to is this going to be definitive or or like so much of what we do it's going to be ah these are some really interesting clues and what's going on um what's what are your hopes for this mars rover well okay here's here's a hope um and a
34:30 - 35:00 quiz okay this is for the for the astronomers can anyone see you can see what we're looking at there okay mike what is it it's a stromatolite it's a stromatolite okay so this is i have one on my desk too so that i was cheating this is it so this is a rock it has this really characteristic lamination to it and you can hold it up a little closer we can so we can see that see that lamination yeah there we go you can see those this kind of lamination curves up and over each one of them so so this
35:00 - 35:30 rock is almost 3 billion years old it's one we collected in western australia and some of the earliest evidence of life on on earth it's like the the the fossil residue of what was once a microbial reef okay this you can see wait wait tell me tell me what a microbial reef is i don't i don't think i know that term but go before plants and animals the planet still has reefs even though there aren't corals even though there aren't algae around and it's it's microbes that are there
35:30 - 36:00 you know making mats and buildups and and you know that you if you've spent time in some coastal areas you step into an estuary it's very mucky it's very a lot of it's very organic um okay that may have felt gross but that's like that's what the earth looked like for for a for a long time before plants and animals and they leave behind a really characteristic fabric and rocks and so this type of rock will if we find this with mars 2020 we're drilling it we're bringing it back
36:00 - 36:30 we're going to be incredibly excited we'll probably throw a giant party but this is this is the thing this is the thing that we're looking for and and i'll tell you right now also that that this rock even though we you know we're 95 sure that that microbes made this rock in part because there are other chemical and physical factors in the environment that are important if we find one on mars the stakes are going to go you know stakes are going to be raised really high and we're going to get to work understanding that in in gory
36:30 - 37:00 mechanistic detail how is it that materials like this get made and what is the exact role that biology is um playing now that's this is something that we could find with the rover right that doesn't require uh drilling a sample bringing it back to the year you know this kind of longer time scale uh part of mars sample rate okay let me let me um let me go to kevin kevin gauntlet's been laid down uh how are you how are you going to know there's life on europa where there was life on your robot that woody's what he's got a pretty compelling answer there well i actually wanted to throw it to
37:00 - 37:30 heather after woody's stromatolites there uh because you know what he's been talking about chemosynthesis and these these uh microbes and you know what i don't know about those specific um microbes but uh a lot of your your favorite microbes uh exhale methane right uh and i actually don't know heather what is the latest on methane and uh in exoplanetary atmospheres uh we think it should be common and
37:30 - 38:00 easily detected at least for planets that are a little cooler than some of the ones we've been observing up until now so i think james webb will see methane everywhere but um by everywhere i mean planets with hydrogen rich atmospheres so planets like jupiter or you know neptune uh so you're you're thinking about seeing nothing in an earth-like planet atmosphere yeah when are we gonna get that uh depends on how much of it there is uh
38:00 - 38:30 methane is easy to see when it's present but if you're talking tiny tiny episodic trace amounts of methane then you know that's always going to be hard yeah okay kevin kevin one minute how do you detect life on europa so we we do have a spacecraft that's going to fly by europa called europa clipper and uh it will get to the launch pad in the next few years but to actually find uh multiple strong lines of evidence of uh
38:30 - 39:00 any signs of life that might be in the the ice of europa uh i really think we need to land and that's uh as mike said earlier a mission that we're working on uh developing uh it's not greenlit yet it's still in the uh development phase we hope we get the the thumbs up to move forward with it in the next few years but um you know then it was well where do you land and mike and i have actually worked together uh he had a grad student samantha trumbo and we combined some lab experiments and some hubble space telescope observations to
39:00 - 39:30 detect sodium chloride on the surface of europa and so i think that if we could put a lander down in a nice salty patch on europa's surface that would be a good indication that we have landed on a place where ocean water from below has come up onto the surface because there are salts there and if there are salts there then maybe there might be mixed in with that some of the organisms should they exist uh that uh
39:30 - 40:00 have also come up from the ocean okay so and i will i will admit here that the big salty patch on europa we have nicknamed margaritaville um i have to uh as as a closing here we have to be on our closing here i i have one question for each of you that i want you to answer and i'm going to ask you a question i want you to give me just your best guess of a probability of something a different one for each of you um you know scientists don't really like to say yes or no they like to give
40:00 - 40:30 sort of probability so give me a probability um woody if we could start the earth all over again from like let's say the moment of the giant impact that that hit the earth that made the moon that's kind of clearly the earth was sterile at that moment because it was mostly molten if you could run that experiment a hundred times how many times would life develop oh that's a great question i i'm i'm gonna i think unity
40:30 - 41:00 i think we i think i i think it's happening again and again and again now i am not so certain that i end up sitting here if you play you know if you play the tape again uh it's not obvious that that we're here we might be highly contingent on a special special history but i think i i think there's a there's high probability that our you know our planet was destined to become living there there might be octopuses sitting in your office instead of you that would be that'll be okay too so that's that's a pretty high number one one when your choice is between zero
41:00 - 41:30 and one one is one is pretty optimistic um so uh so this we'll see how optimistic um the rest of us are here so kevin kevin you're next uh i'm just gonna flat out ask we go to europa uh we we not just that we collect samples from margaritaville and um and you know have them with uh with the lime but we actually drill down into the ocean and and sample the waters in there what is the probability that we find the
41:30 - 42:00 extant microbial life um so i'm going to sidestep your question this is also what scientists like to do not answer questions and simply say that based on what i've learned from life on earth i i predict that the origin of life is easy i say that with with caution uh and so i think that we we will find life elsewhere either evidence of it on mars or living today in europa or enceladus um
42:00 - 42:30 but you know part of what as exciting as it would be to find life within europa's ocean uh the flip side is also true if we search throughout our solar system and beyond and find no signs of life um that is also really profound uh because instead of living in a biological universe we have now learned that uh life is exceedingly rare and the origin of life is very hard and
42:30 - 43:00 we are to some extent it uh now obviously you gotta search really long and hard to to come up with that conclusion that it doesn't exist elsewhere but um a null result is also power powerful scientifically and philosophically when we think about um why we're here and the meaning of life so um okay so let's let's take it let's take it to the galaxy um so as as kevin has said as what he said one of one of the one of the reasons not just for its own
43:00 - 43:30 sake but one of the reasons for looking at mars looking at europa is to try to understand is is it easy how common is life how easy is it to form i i think you know when i when i was a a young astronomer and all of us young astronomers were you know watching cosmos and carl sagan um the big question was well is there other life in the universe or is there no other life in the universe i think we're beyond that question these days i think i think when you look at what we now know about planets around
43:30 - 44:00 other stars there's so many planets there's so many opportunities um it is in my opinion it is impossible that there is not life somewhere in the universe so it's no longer an interesting question to say is there life in the universe i think the interesting question has changed and the question we should all think about is how close is the closest life in the universe um if life is common you look up in the sky and it's every single star you see has something like life if life is really hard to
44:00 - 44:30 make happen then you know maybe we're the only one in our galaxy so heather this is not a probability this is a this is a distance how close is the closest life do you think um other solar system doesn't count i'm gonna say our sort of local arm of the milky way galaxy because i think even just going out that's pessimistic oh okay i mean compared to so woody said 100 that the earth would have
44:30 - 45:00 life over again which i think he means uh pretty common kevin kevin thinks it's pretty common so you know our local arm means like i don't know a dozen in our galaxy is that uh maybe i should ask that question how many how many planets in our galaxy do you think have microbial like life i think it's pretty small because when we look at exoplanets we see many of them look very different than the planets in the solar system so while small rocky planets may be
45:00 - 45:30 common i expect that they're quite diverse i expect they'll have very different kinds of atmospheres very different orbits different planetary systems and i think all that diversity unless life is really general and happens pretty much everywhere i think that diversity might but i think that's why i come down on the less likely sign okay well so we have uh reasons for optimism reasons for pessimism but i think really
45:30 - 46:00 what we have now is uh we actually have we have observations we have experiments we have ways of actually answering these questions in ways that have not been possible in in the past so i'm i'm i'm excited that uh that really within this next generation i think we're going to be able to have actual answers to some of these concrete questions that humans have been asking all this time so i'm going to now um open it up to questions from the audience and thank you for that
46:00 - 46:30 mike and i'd seem to remember that maybe it was steven j gould who asked that question about re-running the tape the film of life and he gave virtually zero odds to us so maybe that uh uh uh some of the microbial finds in west western australia would have evolved into something sitting in front of our zoom screens today instead of us but let's do go to some questions because there are a lot of questions about this and uh let's see oh my goodness so many let's stroll
46:30 - 47:00 stroll right down through question lane here um uh let's see for woody from neil who got his phd in 65. mars has moons does that mean it had tides long ago uh great question i think mike already got into that a bit and and the answer is not big ones mars has mars has moonlits hardly even count as moons they're just little tiny rocks that go around it so so really no tides okay so we would not
47:00 - 47:30 have surfers on mars then let's settle that one here and now they would not be interested in mars um and uh and from uh tyler um asking about exoplanets and those moons maybe you spoke to this but would the moons be better than the planets themselves to look for life uh sure depending on the planet and the moon just like in the solar system if you're the right kind of moon in the right spot you might be promising you could be a very earth-like planet but uh if you're in the wrong orbit or
47:30 - 48:00 if you're too far or too near your star then that's no good so and heather what's the prospect of finding moons around exoplanets i thought we would have found them by now um because they tug back and forth on their planet i thought we would have seen that signal in some of the surveys uh so i'm expecting any time okay uh heather photograph oh sorry heather there in the in the 90s i remember a kind of false alarm i was driving down sunset
48:00 - 48:30 and i heard on the radio that fossilized microbial evidence of life on mars and i actually just stopped the car and listened i was so engrossed and it turned out like not to be so so what are the odds that we're going to find what we think is life and turns out only to be kind of what we're looking for or what we're capable of looking for in terms of the presence of the conditions to sustain life if you're talking about exoplanets i can virtually guarantee that there will be
48:30 - 49:00 multiple claims to see something that is evidence for life that will be hotly debated some of which will probably be disproven down the road it's a high-stakes question a lot of people are really eager to uh be the first ones to find that sign of life i gotta say heather the first time that there is a uh an oxygen a good oxygen detection in an exoplanet atmosphere i'm still showing up at your house with a bottle of champagne yeah whether or not it's from life that
49:00 - 49:30 would be a celebration for sure because your arguments have have ranged from earth is a very bad place for life to earth can be a biological singularity and we'll find out who knows how long from now who's who's right and who's going to be owing champagne to whom here um jay who graduated in 80 says is there a reasonable statistical argument for the existence of life in the universe ooh kevin do you want to try to take that one i don't know about a statistical
49:30 - 50:00 argument but i would uh say that there is a pretty good thermodynamic argument uh just from the second law um we get very precious about life uh because we are it and and we value our lives um but really biology is kind of a layer on top of geology that alleviates chemical disequilibrium in the environment it does so you know woody made reference to electricity earlier and just like if you go to a store
50:00 - 50:30 and buy a double a battery for your flashlight that battery will stay charged for a long time until you put it in the flashlight and turn it on just like chemical energy in a rock will stay in that rock and it'll eventually dissipate but now if you turn the flashlight on the energy from the battery goes out relatively quickly because you've created light biology will extract energy from a rock or from the atmosphere or
50:30 - 51:00 whatever its environment is and help dissipate any stored energy faster so that's not a statistical argument but more of a uh laws of thermodynamics you know technically we refer refer to it as the negative change and gives free energy um arnold who got his phd in 68 says would you expect surface ice on europa to recycle to the interior and if so would you expect to find evidence of life on the surface
51:00 - 51:30 we sure hope so and and part of what mike and i have worked on over the past few years indicates that some of that ocean water from low most likely has come up to the surface and if stuff is coming up to the surface then maybe it's getting cycled into the ocean because you have to kind of balance out um and with the galileo imagery we know that europa's surface is very very geologically young we know that because uh as astronomers and planetary scientists we use craters
51:30 - 52:00 the number of craters on the surface is a metric of of surface age and europa has very very few craters uh but it's got tons of fractures cracks from that title tug and paul and so yeah i think that we might actually be able to find signs of life uh on the surface ice of europa and while mike said that yeah globally the average is probably that the ice is many miles thick there could well be regions where it's a
52:00 - 52:30 lot thinner as long as we're on europa metaphorically at least george wants to know if we can fly a helicopter on mars can we put a submarine into europa that is the dream of dreams george um you know when i was in undergrad uh back in the mid to late 90s jpl released a uh a a graphic of a melt probe going through the ice of europa and discovering hydrothermal vents on the on the sea floor it was sort of a cartoon graphic and the date for
52:30 - 53:00 that mission was notionally 2009 [Laughter] 2009 has come and gone uh and we still don't even have a mission that's flying by but we're working hard to to get that done uh and then also as i mentioned hopefully have a lander and after the lander goes we would know enough to then um uh send a melt probe and upper jpl we are working on variations in in uh the sort of preliminary design of
53:00 - 53:30 what a male probe would have to look like and by now we all ought to be traveling by jet pack too oh we wish um steve from the class of 70 and jim the father and father-in-law of alums says and this is a question that it expands beyond our your earth-centric idea the question is are there plausible alternatives to the carbon-based life we've been talking about and looking for or life on different time scales go for woody yeah yeah that it's a great question because
53:30 - 54:00 it's one of these things that that really okay so what is it that we really unders what are the rules of biology do we really understand them and can we really demarcate them and and and there there's been a lot of work um that's come out of you you might call it even biological engineering or synthetic biology where you say i think i understand the principle i think i understand why dna is important for example well let me then start making flavors of it that are that are totally exotic that don't have and then how do
54:00 - 54:30 they behave well just chemistry i'm just as mother chemic how do they behave and so and that often teaches you things about okay well it's not phosphorus that's so important in dna it's that there's a repeating negative charge okay well maybe that's a thing that we could accomplish with a different element or a different molecule and so so there's there's a there's a really robust um you know again you know ushered in in part with um advances in technology that come through synthetic biology that that are allowing us to answer
54:30 - 55:00 those questions we don't have great answers for them yet and your imagination can still run quite wild um but we're we're starting to understand you know yeah what you know so are there some rules here yeah really you do need to have some components that look like this but but probably some of it's flexible um here's another george um it seems to be george ii here magnetic fields seem to be important to protecting life on earth so what are the prospects for measuring the magnetic field in exoplanets which goes to a question that
55:00 - 55:30 a lot of people are asking how we use different metrics from what we're used to using to to look for some kind of anomaly that may or may not be life supporting life sustaining yeah i think the magnetic fields question speaks to the idea that you need potentially a range of different ingredients to have a planet which is a good place for life and can maintain that over many billions of years magnetic fields
55:30 - 56:00 can affect how a planet keeps or loses its atmosphere but venus is an example of a planet that has a very weak magnetic field but still has plenty of an atmosphere so it's not required in the strict sense but um yeah anything like that moon magnetic field distance from star type of star neighboring planets or lack of neighboring planets that can all affect sort of how that particular planet uh evolves and whether or not it works for life can
56:00 - 56:30 i can i pipe in on this one real quick just because it is a really interesting question so it's one of the things we think on one of the reasons why mars maybe doesn't have water these days is because it didn't have a magnetic or it lost its magnetic field atmosphere got stripped out and i just want to mention a a project being done by um greg hallinan a professor of astronomy who is has a whole set of radio telescopes up in the owens valley who are searching the sky night after night looking at the interactions between stars and
56:30 - 57:00 potentially the magnetic fields of exoplanets so even that uh we're starting to go down the road of learning about how how other planets around other stars have magnetic fields and how they interact what about the technology that you're able to use we talked a lot about that with um with the astrophysics folks earlier in the day you know the arecibo array went down at least one telescope there are are you do you have the equipment um and this what is the state of
57:00 - 57:30 technology with the equipment that you're able to use to look for the things you are looking for [Music] astronomers always like more and bigger telescopes and networks of telescopes i think we could always do better we always wish we had more but um you know certainly i think there's a lot we can do even with the telescopes that we currently have or that will soon be available like the james webb uh this radio telescope array that's searching for signs of magnetic fields is a good example that um you know he hasn't found any yet
57:30 - 58:00 but i think that he he can and he probably will uh so it's certainly within reach to look for stuff like that even with the current telescopes are you are the other panelists in accord with that we i i agree with heather that we always want more telescopes but astronomers are pretty good at figuring out what to do with with what they have there are big radio telescopes down in in chile which are which are able to now
58:00 - 58:30 see the the chemicals that are forming around stars that are going into planets or be able to find planets so it's it's a it's an amazing array of of things that our astronomers are able to to figure out these days oh i was going to say we're impatient i think we'd like bigger telescopes but we don't want to wait around for them so we try and think of clever tricks that can get us there sooner um uh you touched on this in the talk but frank of in 60 of the class of 63 says what
58:30 - 59:00 other techniques can be used to interrogate the atmosphere or any other aspects of an exoplanet do you just look for aberrations um or or i mean interrogate sounds very much like a cop procedural but maybe it's very much the same yeah so you can take a picture where you see the planet uh next to the star and you directly detect light from the planet and you measure its spectrum so that's one way to study it you can look when the planet goes in front of the star and blocks part of the
59:00 - 59:30 star's light that's another technique we can use to see its atmosphere um those are kind of the two main categories and variations on that uh jose who graduated in 79 says what's the role of the moon in earth's biogenesis oh it's a it's a really good question in fact there are there's like some some amazing outstanding questions about like the history of the
59:30 - 60:00 earth moon interaction that are totally unsolved and are like a major bugaboo so you know the moon is retreating from the earth right as it goes you know they tug on each other there's with a little tidal dissipation of energy the moon gets further and further away from us whoa okay so let's unwind that process and ask at the rate at which that's happening when are the earth and moon touching and the answer is only like a couple hundred million years ago well that didn't happen like you know so like there are even just very basic things that we don't understand but it's but it's very important because these are things that are going to control
60:00 - 60:30 orbital parameters on the planet which are going to control climate on the planet and are going to control you know what is happening with the tides and so we have a bunch of questions that we still haven't quite sorted out we also have a bunch of questions that we unfortunately will not have time to answer but gosh thank you all so much um your email boxes may be full of the questions that we weren't able to get to in this particular session thanks to the panel i want to remind you too that kevin has a new book called
60:30 - 61:00 alien oceans the epic quest to find life on water rich moons at the edges of the solar system so maybe some questions that you didn't get in today you will be able to have answered there so thank you to the panel i hope you had a good time thank you everybody absolutely thank you so now let's hear from ralph amos he joined caltech about a year and a half ago as assistant vice president for alumni relations and executive director of the caltech alumni association and i just want to
61:00 - 61:30 say if you all had half as good of time as i did today then your day has been very well spent so mr amos please join us in our virtual campus good afternoon pat thank you and may i extend thanks to you for gluing this all together today it's really a joy to hear the conversations and and i hear the way you foster good exchange again my name is ralph amos i'm in charge of all of my relations here at caltech and it is such an honor to engage with
61:30 - 62:00 this great long-standing tradition 84 years and running we are so proud of all of the faculty and staff and the uh the wonderful alumni that have been involved with making this program such a beautiful experience for all of our alumni around the world i'm here at the love my house and listening to the good conversations and i am so grateful to be a part of this great institution and very grateful and thankful for the staff many of whom you won't ever see that behind the scenes making
62:00 - 62:30 this experience come to life so thanks everyone for your good work the alumni association has gone through a lot this year uh in a pandemic you can imagine how interesting it has been to engage our graduates but through technology uh we're we're engaging more alumni than we've ever engaged before today would be a great example with over a thousand folks chiming in to listen to these very interesting sessions we're also looking at new ways to connect you in personal and professional ways online uh take a look at the new website uh look at the portal and you can
62:30 - 63:00 connect with each other uh 24 7 there we are appreciative for this great opportunity and look for you to stay engaged in the future have a great afternoon stay safe and thank you for being a part of caltech goodbye you