Astrobiology is the discipline that explores the origin of life in the universe, and whether life exists anywhere other than Earth. It’s an increasingly exciting field according to University of Washington Research Associate Michael Wong. Mike reviews the current thinking and provides some of the chemical basis for life as we know it, and possibly as we don’t know it. Planetary Society Senior Editor Emily Lakdawalla explains why we don’t see stars in many images of bodies across the solar system, while Society CEO Bill Nye marks the end of the US government shutdown that has hampered so much science. Five more winners will receive copies of First Man in this week’s What’s Up space trivia contest.
IFE / URI-IAO / UW / Lost City Science Party / NOAA / OAR / OER
Calcium carbonate spire in the Lost City hydrothermal field
At the Lost City hydrothermal field in the Atlantic Ocean, the reaction between seawater and oceanic crust produces calcium carbonate spires up to 60 meters tall. Today, these alkaline vents host diverse biological communities, but roughly 4 billion years ago, they may have been the location for the emergence of life itself.
Michael L. Wong
Chemical garden experiments simulate the chemistry of active hydrothermal vents. In the experiments, two fluids that are in chemical disequilibrium react with each other, and then mineral precipitates grow. These precipitates are analogous to the hydrothermal chimneys that form at sea-floor vents. Chemical gardens illustrate how non-equilibrium systems can drive the emergence of self-assembly and complexity.
This Week’s Prizes: Five winners will receive the brand new Blu-Ray release of First Man, starring Ryan Gosling as Neil Armstrong. And someone else will get the full set of five KickAsteroid stickers from the Planetary Society Chop Shop store and a 200-point iTelescope.net astronomy account.
This week's question:
What planetary spacecraft (not Earth-orbiters) were launched by a Space Shuttle?
What was the last human mission to end with a splashdown in the Atlantic Ocean?
The answer will be revealed next week.
Question from the January 16th space trivia contest question:
What 180 kilometer diameter crater did Chang’e 4 land in, and who is the crater named after?
Chang’e 4 landed on the far side of the moon in von Karman crater, named after aerodynamicist Theodore von Karman, a founder and the first Director of the Jet Propulsion Lab.
Transcribed by Planetary Society volunteer Jake Bathman:
[Mat Kaplan]: Where do we come from? This week on Planetary Radio. Welcome. I'm Mat Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. How and where did life begin? That's the subject of my conversation with scientist Michael Wong. It's a great review of the current thinking about our origins and even some of the chemical basis for life as we know it and as we don't know it. Bill Nye stops by to celebrate the end of the US Government's partial shutdown, and we've got five more blu-ray copies of First Man to give away when Bruce tells us What's Up. Senior editor Emily Lakdawalla has done some more of her great work for the Planetary Society website. Emily you have written about one of these things that now and then troubles me enormously. When you hear from, [00:01:00] I won't even call them skeptics because skeptics ought to base their arguments on fact, but this is one of the reasons that there is a small minority of misled people who believe that we don't go to space and that humans didn't walk on the Moon. It's your January 28th blog post called "Why are there no stars in most space images?" And I want to say you did a terrific job, better than I've seen anywhere else, of explaining why this is. So, why don't we?
[Emily Lakdawalla]: Well there are three main factors that affect whether you can see stars in images that are taken in space. You think that, you know, staring up at black space at night on Earth, you can see lots of stars. And so if you start thinking about it, it seems a little strange that if you see a photo of like an asteroid in space against the blackness of space so you don't see stars in those images, but the fact of the matter is that that asteroid is typically lit by the Sun and so any sunlit surface is so bright that the exposure setting that you use on your [00:02:00] camera is so short that it's not long enough to actually capture any of the faiant stars that are sitting there in the background. So exposure setting is one of the things that affects whether or not you can see stars. It also has to do with the sensitivity of your camera. There are lots of cameras that go to all different destinations in space and the more sensitive a camera is the more capable it is of seeing stars. There's some cameras that get sent to places like Mercury where there is a lot of sunlight and so those cameras are a lot less sensitive than say the ones that are sent to Pluto like the ones on New Horizons. Those can actually gather much more starlight in their cameras than the spacecraft cameras that are sent to destinations close to the Sun. And finally there's a factor called dynamic range and that has to do with how you... with your ability to actually detect both bright things in dim things in the same image. Human eyes actually have pretty wide dynamic range. We're capable of seeing details in [00:03:00] outdoor settings where there's things going on both in sunlight and in shadow, but most consumer cameras are actually very poor at catching things in wide dynamic range. Space cameras can do a pretty good job of getting both dim things and bright things, but you actually have to process the images to be able to see the details that are in the very darkest parts of those images. So I go through all this in great detail on the blog entry with lots of examples that you can see how in sometimes you can see stars in the background of space images and sometimes you can't.
[Mat Kaplan]: There are wonderful illustrations throughout this blog post and I want to say you may have just helped some people buy a new flat screen TV because I bet a lot of people see that HDR, which stands for high dynamic range, and not really known what they were talking about. Again, I really love this explanation. I'm only sorry that the people who probably most need to see it are not going to find it. And so I sure hope that anybody who does see it or hears this is going to share it with their doubting friends.
[Emily Lakdawalla]: I hope so too, Mat. [00:04:00]
[Mat Kaplan]: Thank you Emily. She is the Senior Editor for the Planetary Society. You can see her work, including this January 28 post, at planetary.org. And while you're there you can check out the current edition of The Planetary Report. And now on to the CEO of the Planetary Society, Bill Nye. Bill, it's my first opportunity to wish you a happy New Year at least here on the air, but also to wish you a happy end of the shutdown we hope.
[Bill Nye]: Yes, happy end of the shutdown to people of the world. No, it's very good to not have a government shutdown. It had... it had a big effect on NASA. People were not at work for over a month, which was bad because as we say not only do the tides wait for no one, the motions of planets and and cosmic bodies do not wait for human affairs. So things kept moving through space and contractors who make instruments and rocket systems, if you shut down for a month, it's hard, [00:05:00] it's expensive or it's time consuming to get things running again. So actually, Mat, one of the outcomes of this–if I may judge, silly–shutdown, is that the US Congress may pass legislation that prevents anyone in the Executive branch or Congressional Branch or Judicial branch from shutting the government down. This could be actually an unintended benefit of this recent legislative adventure.
[Mat Kaplan]: I saw that there are actually two bills one from a Republican one from a Democrat which would accomplish exactly that. Sounds like a sensible move to me.
[Bill Nye]: Yeah, here's the thing. If you are hired to run a corporation, you don't show up and shut the corporation down, or the Board of Directors would kick you out immediately. That idea is not... unless you're going out of business, the idea is not to shut the government down. The idea is to run the government. You're the Executive branch. You're the Congressional branch. The idea is to run things, not stop them [00:06:00] for crying out loud. But with all that said, Mat, the Planetary Society kept humming along. You know, we have a lot of members around the world and a lot of members remain engaged with us. All our members remain engaged, and I want to thank everybody for making contributions to our end of the year campaign and for continuing to support us here at the Planetary Society–if I may, shut down aside.
[Mat Kaplan]: Thank you, Bill. And I join you in that gratitude toward our members and everybody else who donated to the Society before the end of the year, which of course is something you can do any time of year, but we did have a big special effort under way and it was very successful and thank you for leading that.
[Bill Nye]: Sure, it's all me. No, it's all you all out there. We are connecting you with space like never before. And you know, Mat, I was just talking to Dr. Betts, Bruce Betts, here this morning and there is a possibility that our LightSail 2 spacecraft will fly this spring. We have [00:07:00] no control over it. The spacecraft is ready to go, the clocks running, the batteries are charged up. We're just waiting for the word, but it will certainly almost certainly fly this summer. So I'm still very excited about that, it's a big event that's coming up. That's possible through the support of our members, and as we like to say, members like you. So thanks for listening to Planetary Radio. Back to you, Mat.
[Mat Kaplan]: Thank you, Bill. He is the CEO of the Planetary Society, Bill Nye the Planetary Guy, and I hope we can talk again soon.
[Bill Nye]: Thank you, Mat. Me too.
[Mat Kaplan]: Astrobiology. The term was first proposed by a Soviet scientist back in 1953. But most of us had never heard of it until just a couple of decades ago. Now it's a firmly established discipline. There's a good [00:08:00] description of the field on the University of Washington website. And that's where our guest Michael Wong is a Research Associate in the school's astrobiology program. Mike studies planetary atmospheres, habitability, biosignatures, and the emergence of life. He's written a featured article for the Planetary Society quarterly magazine The Planetary Report. It's titled "The Making of Life: Grappling With the Emergence of Life on Earth Helps Researchers Understand How to Search for It Elsewhere". Mike recently joined me from the UW campus. Mike Wong, thank you very much for joining me on Planetary Radio.
[Michael Wong]: My pleasure.
[Mat Kaplan]: I very much enjoyed your article in The Planetary Report. It'll be the basis of our conversation, but we may go in a few other directions over the course of this conversation. I don't know if you've heard the two big questions that our boss, the Science Guy, poses wherever he goes. They are, "where do we come from?" and "are we alone?" And it [00:09:00] seems like those are of big concern to you as well.
[Michael Wong]: Yeah, those are both very fascinating questions and the real driving force behind my scientific pursuits. Those are the types of questions that motivate me to get out of bed in the morning and actually go all the way to the office and start typing on my computer.
[Mat Kaplan]: This seems to be getting a lot of attention. I mean, we've had a couple of shows about it recently and we will have more. In this one, I think our discussion might lay out some of the basics and then maybe we'll talk a little bit about the work that you have underway in an area that contributes to this. Let's start where you do in the article. I mean, we mention all the time on this show that you need two things for life and when you have these two things you find a pretty much everywhere. And those are as, I'm sure you know, a source of energy and water. But not just water, liquid water.
[Michael Wong]: Yeah, and we're finding these days that there are lots and lots of places just within our own solar [00:10:00] system that either have liquid water right now or probably had it in quite a large abundance in the distant past. So the prospects are out there to look for life. You start just counting all of the exoplanets that are out there and wondering about whether those have liquid water too and the possibilities just go exponential. So it's a really exciting time to be thinking about these questions.
[Mat Kaplan]: There is an illustration in your Planetary Report article that shows what we think anyway, is that the liquid water on a whole bunch of different worlds, and these are really, they're pretty diverse, aren't they?
[Michael Wong]: Oh, yes. First of all, I should say that I can't take any credit for this diagram. This was I believe a joint production between Emily Lakdawalla and Bob Pappalardo at JPL. So I can't take any of the artistic credit here. But yes, one of the main points that I want to get across in this article is that a lot of the places [00:11:00] where we suspect there's liquid water in the solar system are on bodies that are very different from the Earth where that water is underneath an icy crust not exposed to an atmosphere like it is on Earth. And the big question that we want to try to answer is are those habitable environments and could they be inhabited? And what are the processes by which life might emerge on such a different kind of potentially habitable world?
[Mat Kaplan]: With all of these places in just one solar system, the only one way of easy access to, that that have liquid water, is it now considered reasonable that we're going to find liquid water on worlds throughout the galaxy? Throughout the Universe?
[Michael Wong]: Yes, I believe that it is quite possible that we are going to, within the next few decades, find evidence for liquid water on an exoplanet. But that kind of liquid water will be the same kind as Earth. It will be on the [00:12:00] surface of that world and we will observe it through, for instance, the way that liquid water changes the polarization of light that is bouncing off that planet and into our telescopes or through what's called glint, which is the way that liquid water sort of reflects light very focused and very bright. We see glint for instance on the liquid methane seas of Titan. So we think that we have the capability or will have the capability in the near future to be able to look for glint on exoplanets. Once we have the capabilities to actually get reflected light from those exoplanets that are very far away. It's going to be harder to tell whether we have an exoEuropa-like situation where there is liquid water underneath the surface of an icy crust, because right now we're mainly only sensitive to the atmospheres and soon the surfaces of extrasolar terrestrial planets.
[Mat Kaplan]: So for those that are [00:13:00] more like our own I'm thinking of... I'll invent the term aquasignatures as opposed to biosignatures, which I think we're going to talk about before the... before we finish our conversation. You go on in the article to talk about early thought about how life, the genesis of life on Earth, spontaneous generation. And it reminded me of an illustration from my old life science library books and there is one that really stuck in my mind and it was a drawing of an old rotting log with frogs and flies infesting it, coming out of it. Except that the thinking was literally coming out of it. I mean fully-formed species coming out of this this other living thing. I mean is that what they had in mind with spontaneous generation?
[Michael Wong]: Yeah. Basically, um, before people really understood how biology works, how replication works, it was thought [00:14:00] that we see life everywhere we look on Earth. It must just be popping out of nowhere. And today we know better and it was thanks to this clever experiment by Louis Pasteur who basically had a bunch of different flasks. These flasks had liquid water inside them as well as the nutrients that life needs to grow. He let those flasks sit out. But he made one of the flasks have a very curved neck at the top of it so that are couldn't come inside. What he noticed was that the flask that was open to the air soon became inhabited by all sorts of bacteria, but the other flask which was just as habitable didn't. And then he went further and broke off that curved neck of the the flask that wasn't yet infected by life. Soon it was it was very infected by life. So it was showing that life can't just originate in a sterile but habitable environment it needs [00:15:00] to be seeded from somewhere else which sort of disproved the idea of spontaneous generation. That is we don't actually see separate origins of life here on Earth. Everything on Earth has descended from a single origin of life as best we can tell.
[Mat Kaplan]: In connection with that, you talked about this relative of ours named LUCA.
[Michael Wong]: LUCA stands for the Last Universal Common Ancestor. And we have some vague inklings of what LUCA was like based on what are called phylogenetic studies or looking at the genomes, the instructions written in our DNA and RNA, and trying to backtrack what the most ancient sequences were based on what sequences are highly conserved or highly shared amongst the very disparate types of living beings here on Earth. And in this way, we can sort of get a handle on what LUCA was [00:16:00] like and what environment it lived in and some of the latest evidence points to a LUCA that came from the deep that lived in a hydrothermal setting near the bottom of the ocean.
[Mat Kaplan]: We've talked before on this show about this possibility that life began in one of these settings by one of these hydrothermal vents and key to this is something you also talk about in the article which is equilibrium, or rather the lack of it. Why is this important?
[Michael Wong]: What I like to say is that every living thing needs to eat and to breathe, and we do this all the time sometimes without thinking about it. That's how we gain our energy. Basically by harnessing the disequilibrium, or the in balance in electrons, between the things that we eat and the things that we breathe. When our metabolisms are powering us what they're doing is basically transferring the electrons from the very electron [00:17:00] rich food that we eat to the very electron greedy oxygen in the air that we breathe. And this is fundamentally what powers all of life on Earth is an electron transfer, and things transfer when there is an imbalance. There's a lot of energy in imbalance or in disequilibrium. You can think of being on your tippy toes standing on top of a pole. You're very unbalanced and if you were to fall you would transfer a lot of that potential energy into kinetic energy. The same thing goes with with electrons. They're transferring within us all the time essentially falling down hill and giving us the energy that we need to live. One of the really critical things to understand about biology is it's not just that transfer. That electron transfer goes into pushing a different set of particles out of equilibrium, and those are protons within our body. So electron transfer [00:18:00] creates the energy that is needed to pump protons across a membrane and our mitochondria. Thus creating a new imbalance in the concentration of protons outside of this membrane and inside of our membrane. These protons desperately want to relieve this disequilibrium and can do this by passing through a very intriguing molecular machine, basically a protein called ATP synthase. This then transfers that disequilibrium and protons into a disequilibrium in ATP or phosphates. ATP you may be familiar with from your intro biology classes. Everybody knows ATP as the energy currency of life and the way that ATP acts as the energy currency of life, it is in yet another disequilibrium between its wholesome self ATP, which stands for adenosine triphosphate, which means it has three [00:19:00] phosphate groups in this molecule, and it's broken pieces adenosine diphosphate, two phosphate groups and a lone phosphate that's unattached. Our body works by a basically transforming these imbalances into finally us. And if you really think about it, we are in a state of imbalance with the rest of our environment. We need to fuel ourselves by transforming natural imbalances around us into ourselves. And if we were to go into a state of equilibrium or a state of complete balance with everything else, we would we would essentially be dead. That would not be good. So looking into the way that life works today offers us really good clues to how life might have originated in the deep past.
[Mat Kaplan]: You bring me back to my high school biology class and looking up at the backboard and seeing this complicated cycle and it [00:20:00] didn't hit me until later how important this ATP cycle was, the storage and transportation of energy. So important to this, right, is the idea of a membrane, a barrier that has one condition on the outside and some other condition on the inside. Whether it's the mitochondria those little particles in ourselves those little bodies which may have once been independent living things apparently, but the cell wall and and I guess to some degree our own skin. But really you're talking about things like the cell wall here, right?
[Michael Wong]: Yeah, you're absolutely right. In order to have some kind of disequilibrium or imbalance, you need to be able to separate what's going on inside of life from what's going on outside of life. One way to look at life again is that we are in a state of low entropy with respect to our surroundings. That's how we maintain our order and our complexity is by separating ourselves.
[Mat Kaplan]: And that's a good thing. We [00:21:00] should say low low entropy is a very good thing.
[Michael Wong]: Yeah. That's right. Yeah, we all want to be low entropy and and the key... and the key to being low entropy or to maintaining our order and our complexity is to raise the entropy of everything outside of us. That's actually really the only way to maintain low entropy inside of us over time. If we don't want to be flooded by all of the extra entropy that we are creating outside of us, we better have a membrane.
[Mat Kaplan]: You already mentioned the possibility that life began at one of these hydrothermal vents or maybe more than one. No, not likely, I guess since we all are so similar. What was it about the hydrothermal vent that contributed to this disequilibrium that was so critical to life?
[Michael Wong]: Yeah. That's a great question. When we're looking for places for life to emerge and in particular for the type of metabolism that would lead to what we see [00:22:00] in life today, we definitely want to look for disequilibria and focusing points for the specific kinds of chemical and physical disequilibria that are exhibited in life today. At the bottom of the ancient ocean, and first of all, this ancient ocean was probably full of a lot of CO2 and therefore was slightly acidic, sort of like a lightly carbonated soft drink. When this sea water dives into the ocean crust, it will participate in a reaction with the minerals in the ocean crust. And this reaction has a fancy name It's called serpentinization. While I was typing about serpentinization my little sister looked over my shoulder once it was like, serpentinization, is that like a Harry Potter spell when you get turned into a serpent or a snake? And I was like no no no, serpentinization is just just the chemical reaction between sea water and rock. [00:23:00] But what happens is that it changes fundamentally the water. So when it comes back up this water is instead of being slightly acidic extremely alkaline, meaning that there is a huge pH gradient between the fluids that are coming out of this vent and the ambient sea water around it and pH is a concentration of protons, which is exactly one of the the gradients that we hardness in our own cells. And furthermore this water that is coming out of these serpentinizing vents has lots of hydrogen and methane and relative to CO2 hydrogen and methane are very electron-rich. They would love to donate their electrons to more oxidized or more electron greedy things like CO2, or perhaps other oxygen bearing compounds that were in the early ocean. So in that way there is this what scientists call redox [00:24:00] gradient or gradient in electrons. That is again what fuels all of life today. So there are these two fundamental gradients at these hydrothermal vents that are very very similar to the gradients or disequilibria that we harness today.
[Mat Kaplan]: Are we making progress toward understanding how this fairly simple, easy to understand fortunately, disequilibrium might have led to the formation of the complex organic molecules that were necessary for life?
[Michael Wong]: That's a great question and it is a topic of ongoing research. There is a group at JPL led by Dr. Laurie Barge working on basically simulating these hydrothermal vents, and if you look at page 17 in The Planetary Report from December I have a picture of one of her test tubes.
[Mat Kaplan]: I'm looking at it now, yeah.
[Michael Wong]: Yeah, it's a chemical [00:25:00] garden. This is a fairly simple set up here, where basically she is showing how chemical disequilibria can translate into these fabulous low entropy, highly complex structures. These are analogs for the hydrothermal vents. Now instead of just having a test tube, she's got lots and lots of more complicated lab setups where she can slowly inject analog hydrothermal fluid into a larger container. She can also inject things like organics which will interact with the minerals and interact with each other inside of the structures that she's producing. So this is ongoing work and it's a very exciting field that we are just scratching the surface of. I should tell you about this dream that I had once. So I used to teach the astrobiology class when I was at CalTech. I brought Laurie in every year to do a lab with us and make these little analog hydrothermal [00:26:00] vents that you can see here in the in the Planet Report article. My dream, I dreamt about taking my astrobiology class on a field trip to JPL. Not that far away from CalTech. And in my dream at JPL Laurie had created this huge tank that basically simulated real life, large-scale hydrothermal vents that you would then put on a scuba diving suit on and you would go inside this colossal tank and you would be able to observe serpentinization vents in their full glory. Because right now it's very hard to get down to them. You can see a photograph of the lost city hydrothermal vents in on page 16, the opposite page of the article. These are at the bottom of the Atlantic Ocean and not many expeditions to these vents have been taken. I actually don't know how many but it's probably, you can count them on one hand. And so we know very little [00:27:00] about the geology and the ecosystems that are actually happening down there and we need to learn more. We need to go back and learn more.
[Mat Kaplan]: Do you mind if I borrow that dream? I'd love to have that and do a little scuba diving around these more easily accessible hydrothermal vents. You know, if you were to tell me as I look at this picture of this test tube that what I'm looking at is alive. These these turquoise deposits with little filaments coming out of the tops of them and and we'll put some of these images on the show page at planetary.org/radio on this week's show page. You can also of course read The Planetary Report online at planetary.org and you can see all of these great illustrations and read Mike's article. If you were to tell me these were alive I'd say, okay, I'll buy that.
[Michael Wong]: Yeah, absolutely and this just speaks to the great power of disequilibria driving complexity and orderliness in natural [00:28:00] systems. And also to the fundamental connection between geology and mineralogy and life. I really think that it's at a place like this where you can harness not just aqueous chemistry, but also surface chemistry and catalytic chemistry from metal bearing minerals that would have sparked something as complex and as wonderful as the first biochemistry. And indeed, I don't know if this is going on too much of a tangent, but when we look at the enzymes and the proteins that do a lot of the heavy lifting in our own cells, we see at their very core doing a lot of the electron transfer mineral-like structures. Things that contain iron, things that contain molybdenum, things that contain nickel. This hints at a past that was very much intertwined with the mineral world. So it's not just aqueous chemistry. It's a lot of [00:29:00] transition metal chemistry as well happening in our very own bodies today and probably at the origin of life itself.
[Mat Kaplan]: Well if that's a tangent, it's a very relevant and fascinating tangent. You mentioned in the article, which I did not know, that the Mars exploration rover Spirit found some evidence for hydrothermal activity, in the distant past of course, on Mars.
[Michael Wong]: Yeah, we have evidence from rovers and I believe also remote sensing from our orbiters around Mars that are looking scanning Mars' surface for minerals, that Mars' surface has participated in these types of water-rock reactions. Probably most of these reactions happened billions of years ago, three to four billion years ago, but Mars was a very active chemical and geochemical place. And a lot of people wonder could early Mars have looked a lot more like Earth? And if so, could it have had a separate [00:30:00] emergence of life?
[Mat Kaplan]: So a Martian genesis. And then of course you also talk about this possibility that maybe life didn't originate on Earth. Maybe we're all Martians.
[Michael Wong]: Yes indeed. I would have to say that this is not a hypothesis that most astrobiologists think is likely but there are a few strong proponents out there. One of them is Professor Joe Kirschvink at CalTech who I was lucky enough to take a class from and he definitely talked about this hypothesis. Joe thinks that we are all Martians and not only that but we are all Tharsians or coming from The Tharsis province on Mars. The reason for this I'll just outline a few reasons briefly. Joe is a proponent of the idea that you need wet and dry cycles to facilitate the first biochemical reactions, in particular the polymerization or the linking of building blocks for life. [00:31:00] I should pause here and mention that that is something that is distinct from the origin of life hypotheses at hydrothermal vents where there's obviously no drying cycles there, but if indeed you do need some wetting and drying cycles, early Mars may have been a much better place to harbor the emergence of life than early Earth because as I mentioned in my article, the earliest part of Earth's history was probably characterized by a global ocean, one where there were very few landmasses. Mars on the other hand has a lot less water than Earth, or had a lot less water than Earth even in the distant past. In particular the Tharsis region with these giant shield volcanoes the largest volcanoes we know of in the solar system would have definitely stuck above any putative ocean that was on early Mars. Volcanoes also tend to drive lightning and they stick up high into the atmosphere where there might have been oxidants, those electron [00:32:00] greedy things. So a warm little pond on the edges on the slopes of Tharsis may indeed have been a very great place to do some exciting prebiotic chemistry.
[Mat Kaplan]: And this of course makes me think of what Charles Darwin referred to as the warm little ponds which before we discover those hydrothermal vents is what a lot of people were thinking about for the the genesis of life. You told me you got to hear the our recent episode where I talked to those researchers at McMaster University in Canada. Much like the work at JPL with hydrothermal vents, they're trying to simulate what might happen in these little maybe tidal pools that regularly are inundated with water and then dry out. Are you supportive of that kind of work? Does it sound interesting?
[Michael Wong]: Oh, absolutely. Yeah. I think that the McMaster group is doing a great job over there and I'm very excited for what the... whatever they discover. I guess my goal with this article, I focus mainly on the alkaline [00:33:00] hydrothermal vent theory for the emergence of life because I think that most people who are educated about the origin of Life are familiar with the idea of this warm little pond, which is still a very prevalent idea in the scientific community today. So I wanted to expose a general audience to a different origin of life hypothesis that had implications for places like Europa and Enceladus. But I absolutely think that the the McMaster group and other groups around the globe who are working on warm little ponds and the chemistry that could be happening in them are are doing a wonderful job. The main thing that those groups are after is looking for the first self-replicating molecule, which many people assume to be RNA because of RNA's dual capabilities as an information storage molecule and as a catalyst. Very importantly it's known to be able to catalyze its own creation, given ample supply of building blocks. The main trouble is that it's very hard to create the very [00:34:00] first RNA molecule from scratch. Scientists like our McMaster colleagues are seeking the mechanisms and environments by which this might have been done and so understanding the beginnings of replication is absolutely important work in the field of astrobiology and the origins of life and I wish them the best of luck.
[Mat Kaplan]: How about life as we don't know it? I happen to know that you're a science fiction fan, particularly a Trek fan, because in fact you kind of based your own webcast, Strange New Worlds, around the science of Star Trek, one of my favorite topics. Science fiction has no shortage of life as we don't know it. Elizabeth Turtle of the proposed Dragonfly mission recently told us that her spacecraft if it makes it to Saturn's moon, Titan, is going to be looking for prebiotic conditions on the surface of that very cold world. Can you imagine life evolving there?
[Michael Wong]: Oh, yeah. That's, that's a really great question. Let me say that I'm a big fan of Dragonfly and of Titan. [00:35:00] So without going into too much detail, life on Titan would be fundamentally different from a biochemical point of view for three main reasons. One is that it's very cold, like you said. Life would need to be able to have reactions that actually proceed at those extremely cold temperatures. Two, the liquid on Titan is liquid methane for the most part. Methane is very chemically distinct from water in that water is a polar molecule. Meaning it has a slight electrical charge to it on different sides of the water molecule itself. And this is so essential for the ways that life operates on the nanoscale. Methane on the other hand is nonpolar. Any biochemistry would have to work inside of that medium and it's very hard to imagine what kind of biochemistry that would be. And [00:36:00] finally Titan has very little available oxygen. Oxygen is one of the four most prevalent building blocks of life on Earth. But Titan, while it has a lot of hydrogen, carbon, and nitrogen, has very very little oxygen because it's so cold and most of that oxygen is locked up in solid water which forms the crust of Titan. So we'd have to imagine an alternative biochemistry that doesn't take advantage of oxygen at all. For those three reasons life on Titan would definitely be life as we don't know it.
[Mat Kaplan]: Let's say that someday, probably won't happen with dragonfly, but you never know, we discover that there was a second genesis of this very different sort of Life on Titan. Maybe we find evidence of some very different type of life on Mars. I think I know the answer to this, but what would this second genesis [00:37:00] within our solar solar system, what would it mean for the prospect of life across the universe?
[Michael Wong]: There is an old saying that goes there are only three numbers in physics: zero, one, and infinity. Since we know that the number of instances of life in the universe is not zero, it's either one or infinity and so finding another instance of life within our own solar system means that you know, there's just so many possibilities out there. We're very unsure of whether life was a fluke accident or whether it's some kind of result of the way that matter and energy like to organize themselves. You can argue it either way. But until we go out there and really get a lay of the land and say, look the rest of the universe seems to be completely barren. Or, look, there are other instances of life out there and here's how they came to be and [00:38:00] there's some underlying principle like for instance the dissipation of disequilibria that drives them into existence that we will get an understanding of our place in the cosmos.
[Mat Kaplan]: Thrilling stuff, Mike. Before we close, tell us a little bit about the work that you have underway at the University of Washington.
[Michael Wong]: Yeah, sure. I'm currently looking at the ways that we can actually try to find life on an exoplanet or how we might be fooled into thinking that there's life there when those signals were actually made abiotically. So in particular we're concerned with looking for oxygen. And oxygen is a very good bio signature, we think, because Earth's atmosphere is full of oxygen and all of it was created by life and particular photosynthetic plants, algae. The question is, is there a way to create oxygen, high levels of oxygen [00:39:00] in a planet's atmosphere, without life. People have come up with different theories for this and one good way to create a lot of oxygen is by shattering CO2 molecules, carbon dioxide molecules, with ultraviolet light. CO2 obviously has a lot of oxygen locked inside of it, so if you break it apart, you might create molecular oxygen, O2. This could happen on planets with very thick CO2 atmosphere such as Venus. So our neighboring planet Venus has about 90 times the atmospheric pressure of Earth. And most of that is CO2. And yet, Venus, although it's being bombarded by lots of ultraviolet radiation from the Sun doesn't build up abiotic oxygen and we think this is due to the chemistry that is happening on Venus's atmosphere involving exotic species, like sulfur and chlorine atoms that are floating in Venus's atmosphere that regenerate the CO2, rebuild it so that oxygen doesn't build up. [00:40:00] And we're wondering if those mechanisms for scrubbing out oxygen and reforming CO2 actually work around other types of stars. And the most exciting type of star right now is an M. Dwarf star or a very red dim star.
[Mat Kaplan]: This is the most common type of star right?
[Michael Wong]: Exactly. Yeah, most of the stars in the galaxies are M dwarfs, and we're finding planets by the bucket loads around M dwarfs some of which are in the habitable zone. And what we don't want to do is accidentally find a Venus-like planet that has built up a lot of oxygen through shattering by ultraviolet light and mistake that for a planet that has a biosphere that is making that oxygen. I'm looking into whether or not those types of planets, Venus-like planets around M dwarfs, do or do not build up oxygen abiotically.
[Mat Kaplan]: You must be very excited looking forward to the new generation of [00:41:00] telescopes, the James Webb Space Telescope and the ground-based Scopes that might give us this ability to detect oxygen in the atmospheres of these exoplanets.
[Michael Wong]: Absolutely. Like we said at the very beginning this is a wonderful time to be alive and asking these questions because the technological capabilities whether within the solar system with Dragonfly investigating the chemistry on the surface of Titan or telescopes that will stare light years away at planets that are orbiting distant stars and get a handle on what they're made of and whether they have life. It's just so invigorating to go to work every day and realize that we are on the cusp of an astrobiological revolution perhaps.
[Mat Kaplan]: And that is probably a great place for us to end this very exciting and fascinating conversation. Thank you, Mike. Live long and prosper.
[Michael Wong]: Thanks you too.
[Mat Kaplan]: Mike Wong is a Research Associate in the University of Washington astrobiology program, and he studies planetary atmospheres, [00:42:00] habitability, biosignatures, and the emergence of life, which of course has dominated our conversation today. He as I mentioned has his own podcast. You can find it, Strange New Worlds about the science of Star Trek. His article in The Planetary Report, and this by the way is the Winter Solstice issue of The Planetary Report that you can find a planetary.org is titled "The Making of Life: Grappling With the Emergence of Life on Earth Helps Researchers Understand How to Search for It Elsewhere". On now to this week's edition of What's Up with, you know who, Bruce.
[Michael Wong]: Oh Bruce, can you give me a Random Space Fast?
[Mat Kaplan]: I'm so glad you thought of that. I always forget. Time for What's Up on Planetary Radio. The chief scientist of the Planetary Society is Bruce Betts, and he has joined us once again to tell us about the night sky, and we'll do a bunch of other fun stuff [00:43:00] including giving away five more copies of First Man that great movie about Neil Armstrong. Welcome back.
[Bruce Betts]: Thank you, good to be back, Mat. So you still got the pre-dawn is where the planetary party is happening and things are shifting around relative to each other. If you pick this up soon after comes out then on the morning of February 1st you will find the Moon hanging out between Venus, super bright Venus and very bright Jupiter in the pre-dawn East. If you look some other morning, you'll still see Jupiter and Venus up there looking spectacular. And yellow Saturn much dimmer than the other two is below the other two climbing and passes above Venus around February 18th. It's a party, it's a planetary party, and lonely Mars is still hanging out in the evening sky, but continues to fade and get lower in the west.
[Mat Kaplan]: Did you see my little image of Jupiter and Venus hanging out next to the palm tree last week? [00:44:00]
[Bruce Betts]: Glad you brought it up, that was spectacular and it shows not only what an amazing photographer you are with your phone, but how bright and stunning they are. But it was very nice framing with the palm tree. It was lovely.
[Mat Kaplan]: Thank you. Thank you. I had nothing else to do. So I stood there freezing on the train platform.
[Bruce Betts]: Well, I'm glad I could provide some planets for you to take pictures of. Now we move on to This Week in Space History. We mentioned last week, but I'll mention again, this was this week the Columbia disaster occurred. Seven astronauts died, we remember them. Much happier news in other areas of space; in 1958 Explorer 1 became the US's first satellite. 1961, hey chimp Ham, suborbital flight. Way to go, Ham. And 1971, Apollo 14 launched and landed on the Moon.
[Mat Kaplan]: I wonder if Ham is in the International Astronaut Hall of Fame. I'll have to check. I'll have to look online. [00:45:00]
[Bruce Betts]: Is he a member of the Association of Space Explorers?
[Mat Kaplan]: I don't know that's a good question. Maybe he's the mascot.
[Bruce Betts]: All right, we move on to Random Space Fact. Wow. That was possibly the worst chimp impersonation I've ever heard.
[Mat Kaplan]: Oh, I was going to tell people I got Ham to do a celebrity intro for you.
[Bruce Betts]: Maybe you can edit this show so that no one will know.
[Mat Kaplan]: That's what I'll do. No one will ever know.
[Bruce Betts]: Exactly. We're going to talk, against my better judgment because I still don't believe Einstein and his crazy jokes, but we're going to talk general relativity. As you may be aware, one of the first things that general relativity explained that no one had been able to explain was the procession in Mercury's orbit. So every... the closest point in Mercury's elliptical orbit to the Sun in purely Newtonian fun with only those two bodies would stay in the same place. [00:46:00] Tugs of other planets and other things make that periapsis move over time, but they have this discrepancy of about 43 arcseconds per century and it turns out general relativity and its wacky way explain this by gravitation being mediated by the curvature of spacetime or as I like to call it General Gelativistic Hoo-Doo. But here's an interesting tidbit I throw on, which I had not heard as much but makes sense. Mercury, this general relativistic effect is 43 arcseconds per century. Well, it happens for the other planets, too. Venus, and it's been measured now for Venus at a little under nine arcseconds per century and Earth at a little under four arcseconds per century,effect of general relativity on the periapsis procession. There you go. There you go.
[Mat Kaplan]: Albert is up there giving you a nice little wink.
[Bruce Betts]: He probably doesn't enjoy [00:47:00] saying I don't believe his jokes.
[Mat Kaplan]: I love this actually a because it's such a great story from the history of astronomy. Astronomers I think up until basically up until Einstein were looking for that other planet Vulcan because they couldn't figure out why Mercury was behaving the way it was. And it turned out it was just one of Albert's little pranks.
[Bruce Betts]: All right, we move on to the trivia contest. I asked you what 180 kilometer diameter crater did the Chinese Chang'e 4 land in and who is it named after? How'd you do, Mat?
[Mat Kaplan]: As we get more entries for the contest, it's becoming more difficult to review all of these and to decide which ones we have time to read because we get so many great responses. The person that random.org chose this week, and that's William Fisk in Palm Bay, Florida. First time entry. That crater that I think you're looking for is von [00:48:00] Kármán crater.
[Bruce Betts]: That's correct.
[Mat Kaplan]: 180 kilometer crater. Yeah, well congratulations to you, William. Nice work. You've just made a whole bunch of people who enter...who have entered every week for ages very very envious.
[Bruce Betts]: Did he say who it was named after? Let me see if it... yes, Theodore von Kármán considered the father of supersonic flight.
[Bruce Betts]: There you go.
[Mat Kaplan]: I forgot that you asked for that. We're going to send William that signed copy of Alan Stern and David Grinspoon's Chasing New Horizons: Inside the Epic First Mission to Pluto, along with a full set of Kick Asteroid stickers from the Planetary Society and The Chop Shop store developed in collaboration with the Chief Scientist who we're talking to right now, and a 200 point iTelescope.net astronomy account from iTelescope, the worldwide network of telescopes that William will be able to use to, I don't know, you can check out that procession of mercury, I suppose if he's [00:49:00] really really careful.
[Bruce Betts]: Indeed.
[Mat Kaplan]: I got a bunch more. Here's one from I'm just going to say Vincent in San Jose, California, because indeed he says his last name is impossible for the American tongue. It's something like "Nan-jill-helm" ... "najul" ... "nan-jin-helm". He said, as a lot of people pointed out, that Theodore von Kármán was the PHd advisor for Xian Xu... well, I can't do this one either, but he's the founder of the Chinese space program. Coincidence? Chinese Lander on the far side has come down in this crater? Vincent adds, now there's Karma-n for you. Oh good. I wasn't sure I got that across right. Mark Sulfridge in Boise, Idaho. He says, as a CalTech Alum class of '92, von Kármán's name was very well known to me even prior to researching [00:50:00] this question. I have attended several lectures in von Kármán Auditorium, which I think of as almost hallowed ground. You and us both, Mark. von Kármán Auditorium, which is of course at JPL. But von Kármán was I'm sure you know, he was the first director of JPL, right? One of the founders.
[Bruce Betts]: Yeah, he started their crazy experiments in the Arroyo that eventually evolved into JPL and indeed and he also was a CalTech professor. Only zou reinert in Germany and Thomas Hurdle in Inver Grove Heights, Minnesota, there's another interest in town, they said that he was also the first to explain this thing which now is called–and I thought it was a joke at first but I looked it up–the Kármán vortex street. Have you ever heard of that?
[Bruce Betts]: No, I have not.
[Mat Kaplan]: Yeah Wiki it. It's a real phenomenon it having to do with fluid dynamics and stuff that happens in a fluid when it hits a blunt [00:51:00] body and it makes these really pretty little vortices and they're called the Kármán vortex street. I have no idea why they call them a street. But anyway, it's it makes real pretty pictures. Richard Hoffman in Greenport, New York. He says, I wonder if Roger Waters would mind changing the album title to Far Side of the Moon.
[Bruce Betts]: Wouldn't that make everything less confusing?
[Mat Kaplan]: Pink Floyd fans out there, of course. Brian Jones of Alexandria, Virginia, boy have a lot of stuff today. He says Chang'e 4 landed in the Aitken basin, which is not what we were looking for, but it's true because von Kármán crater is in the Aitken Basin. He says that was named after American astronomer Robert Aitken who suspiciously was awarded the Bruce Medal in 1926. Explain that one, Dr. Betts.
[Bruce Betts]: Why haven't I gotten the Bruce Medal? Oh wait, I have it right here. I was [00:52:00] thinking that would be a great thing for us to give out as a Planetary Radio prize, the Bruce Medal. But apparently it's already taken.
[Mat Kaplan]: We could just say the real Bruce Medal or the genuine Bruce Meadl or something like that. We will close with a not a not a full poem this time. Well, you know, it's a it's a haiku. It came from Sven Newhouse in Germany. Far Side of the Moon such yearning in so few words the unknown beckons. We get in a haiku mood at the Planetary Society now and then maybe this will kick another one of those off. I know what we should kick off which is another contest.
[Bruce Betts]: All right. What planetary spacecraft, and by this I mean things that are not Earth-orbiting satellites to be clear, so something that goes beyond Earth orbit, were launched by the space shuttle? So launched by one of the space shuttles, planetary, [00:53:00] in which case I mean not Earth-orbiting satellites. Go to planetary.org/radiocontest.
[Mat Kaplan]: I couldn't name one for you, but I definitely have heard of a couple. You can tell us what they are. You've got until Wednesday, February 6, at 8 a.m. Pacific time to get us the answer and you will... well, five of you will win copies of First Man, that movie biopic of Neil Armstrong which has been nominated, I think, for a few Academy Awards. I should have checked that out since the last time we talked. And we will given someone else set of those Kick Asteroid stickers and what the heck a 200 point iTelescope.net account. I think we're done.
[Bruce Betts]: All right, everybody go out there look up at the night sky and think about what the criteria should be to win the Bruce Medal. Thank you. Goodnight.
[Mat Kaplan]: I think you should have to do a really great chimp impression. [00:54:00]
[Bruce Betts]: I can't even do it.
[Mat Kaplan]: That's Bruce Betts. He's the Chief Scientist of the Planetary Society who joins us every week here for What's Up. And by the way, they're blu-ray copies of First Man. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by it's life-affirming members. MaryLiz Bender is our Associate Producer. Josh Doyle composed our theme which was arranged and performed by Pieter Schlosser. I'm Mat Kaplan. Ad Astra.