SCIENCE FICTION UNIVERSITY: Kristine Nielsen on Astrobiology

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Welcome to our infrequent, but well-intentioned “Science Fiction University” feature, in which we attempt to explain, expound, enlighten, and just generally explore the ideas surrounding SF. This is the first SFU to be in the form of an interview, but given the level of scientific content, I figured it was appropriate.

With us today, we've got Kristine Nielsen, a relatively new visitor to the Republibot website, and a former intern at the Jet Propuslion Laboratory, an astrobiologist, and a paleoclimate researcher. She's graciously agreed to be interviewed by us today, because we like science. Science is our friend.

Kristine, thank you very much for talking with us about astrobiology today.

KRISTINE: Thanks for having me. I'm always happy to talk science--especially cool stuff, like extrasolar planets and origins of life and such.

REPUBLIBOT 3.0: I guess the best place to start would be the obvious question: Do you believe there is life in outer space? My own opinion is that it's highly unlikely, but not entirely impossible. I know that's an unpopular opinion at present, but what do you think, and why?

KRISTINE: I think it's highly probable there's life outside our planet, for sufficient definitions of life. If we define life as something that feeds on negative entropy and is capable of reproduction and adaptation I think it's highly likely life has arisen someplace else. Life arose here--as far as we can tell almost as soon as the bombardment of the Earth ended--which suggests it must be more probable than not once the right conditions are achieved. Now, what life looks like, and especially if it's something we can communicate with, is a completely different question. I suspect there are a lot of planets out there with ecosystems that are based primarily on unicellular life and never get beyond the goo stage. For those few that evolve multicellular life, most organisms will probably be like most life on Earth--focused on eating and avoiding being eaten and so not terribly interesting to talk to.

To get organisms that want to communicate, and are interesting to talk to requires that those traits have an evolutionary advantage long before any of what we consider technology comes out of it. In the case of humans, it's likely the reason we have big brains and the resultant complex language and logical reasoning is as much because it's sexually attractive--in both genders--as because of the other advantages those adaptations give us.

And the fact that smart is sexy is just random chance and good mate choice--there are any number of other very human traits that could have been subjected to sexual selection that would have led to a very different, very much less smart outcome for humans.

REPUBLIBOT 3.0: What are your thoughts on the infamous Drake Equation? Be as brutal as you like...

KRISTINE: Ah yes, the ‘let's make up numbers game.’ I love back of the envelope calculations and this is one of the more fun questions to tackle. Let's see, pulling that equation out of the wonderful treasure trove of knowledge that is wikipedia:

N = (rate of star formation) * (fraction with planets) * (number capable of supporting life) * (fraction that develop life) * (fraction of life that's intelligent) * (and communicates) * (length of time civilization exists)

Most of these numbers we don't know and can't measure, but we can estimate. For those who are skeptical, it's a useful though exercise, even if we know the answer is likely to be wrong. Anyway, I'll take the rate of star formation as 10/year, just like Drake et al. Being an optimist about some things, I'll assume 60% of solar systems have planets and 10% of those are capable of supporting life. I'm also going to assume 90% of those that can support life will at some point develop life.

REPUBLIBOT 3.0: I’d probably pick a lower number for solar systems that have planets, simply because most stars exist in Binary, Trinary, or larger systems, and it’s pretty unlikely planets could form in that kind of gravitational environment…

KRISTINE: Here's where I get pessimistic. I don't think intelligence is likely, so I'm going to assume 0.001% of those planets with life will ever produce intelligent life, and of those only 5% will choose to communicate. The length of time civilizations exists and are capable of communication probably depends a lot on whether the ancestors were competitive or cooperative, but then so does the probability of communicating in the first place. I'll just assume a civilization capable of communication will last somewhere on the order of 5000 years before it burns out, so that gives me an estimate of:

N = (10) * (0.6) * (0.1) * (0.9) * (0.00001) * (0.05) * (5000) = 0.0014 civilizations existing at any given time.

So, I'm pretty squarely in the ‘Rare Earther’ category, though I do expect there have been and will again be intelligent life in the universe. Order of magnitude calculations like this are fun--and, as in the case of the Drake equation, where you do make up a lot of the numbers--are probably more informative about the person you're talking to than anything else. It's a good way of figuring out in a more concrete way what people's biases and beliefs are. I'm obviously optimistic when it comes to the physics and chemistry, but pessimistic when it comes to evolution.

REPUBLIBOT 3.0: Interesting distinction! I’ve heard lots of people decry the equation as basically nonsense - I’m kind of one of those myself - but I’ve never heard anyone describe the Drake Equation as more of a thought experiment/Rorschach test than anything else, but of course that makes perfect sense. It's interesting to me that fifty years ago, most people didn't believe in extraterrestrial life, but now, thanks to half a century of movies and TV, it's sort of taken for granted. I remember reading criticisms of Ozma and SETI when the programs were new effectively poo-poohing the waste of money involved in such a wild goose chase, and now a lot of people oppose 'em for the opposite reason: Why use all that time, money, and equipment to prove something that your average cab driver and gas station clerk already believe exists anyway? Do you think this has worked against NASA to any degree? What I mean is: Had they found life in the sixties, lets say, that would have probably been a huge, huge moment, but now it's a 'diminishing returns' situation with regard to public relations. Most people I've spoken with seem to think that if Dejah Thoris herself were discovered on Mars tomorrow, the world would respond with a resounding "So what?" because the concept has grown rather passé. What's your take on the public's take on that?

KRISTINE: Oh, I don't know--I think the public response would be quite a bit more varied than just, "So what?" I think you're right that a lot of people simply won't care, but I hope the lack of imagination and passion that would produce that reaction doesn't characterize the majority of people. I think people would surprise you. Honestly, I'd expect the vast majority to feel threatened at first because we're no longer alone, or worried that the life from another planet is less than altruistic, shall we say. Eventually, though, people would come to grips with the existence of intelligent life other than us, and maybe even decide it's cool life exists outside our solar system. But we do have to find it first, and that's the hard part.

It's hard enough to thoroughly explore the planets in our own solar system, both in terms of finances and in terms of the public interest needed to keep a truly expansive space program going. So in that sense, yeah, NASA has probably suffered, simply because it is taken for granted that there's life out there, when in reality it's just not that sure. We could really be the only thinking, communicating beings out there, or we could be one of millions of similarly smart, interesting creatures out there, but we don't know and we're not currently committed to figuring it out.

REPUBLIBOT 3.0: Understand, I'm not saying we shouldn't look. Just because I think it's highly unlikely we'll find anything doesn't mean it isn't there. As long as we're going anyway, what's one or two more experiments? I am a bit more critical of SETI, though. We've pretty much established that any artificial EM broadcasts from any star would be so dispersed as to be completely unintelligible by about one light year from a star, so we're never going to hear those alien equivalents of Fibber McGee and Molly that we've been waiting for, never gonna' see the alien iteration of Gilligan's Island, even if they're broadcasting it. What's your take on this? And is there any kind of rivalry between Astrobiologists like yourself and the SETI folk? Fighting for funding, stuff like that?

KRISTINE: Astrobiologists don't really fight for funding with SETI anymore. SETI is pretty much privately funded, so there's no overlap there. I do see a lot of astrobiologists running SETI at home on their computers, so there is some competition for CPU time, but that's about it. There might be some small amount of competition for people, but I think Astrobiology tends to win more often than SETI because of the funding issue and because there are so many other, potentially more revealing and exciting things to do than listen for signals that we probably can't pick up anyway.

REPUBLIBOT 3.0: Honestly, do you think it's likely that there was ever any life on Mars?

KRISTINE: I do think it's pretty likely there was once life on Mars, though I admit that may be wishful thinking on my part. I don't know we'll ever find evidence of it, especially if we never physically go there, but I think it's highly likely life either evolved there or was transported there from Earth. It's surprisingly easy to get pieces of rock from one planet to another, and since most of those rocks are surficial, they're likely to be teeming with life (as long as they aren't sterilized by staying in space for too long). There's even a hypothesis out there that life evolved first on Mars, not Earth, since Mars was in the Goldilocks zone before Earth was and probably stabilized first, too.

REPUBLIBOT 3.0: Panspermia.

KRISTINE: Again, without going there and looking around for some really old rocks with evidence of Earth-like-but-more-primitive life in them it's not possible to test, but it's an interesting idea. Life could have originated on Mars, where conditions were favorable earlier, and then been transported to Earth. That would explain the relatively early appearance of life here, basically as soon as bombardment stopped. Otherwise, you pretty much have to assume life starts ridiculously easily given the right conditions that we can't figure out yet.

REPUBLIBOT: One thing that's interesting to me as a pro-Science conservative is how many social conservatives are really solidly opposed to the notion of extraterrestrial life. Some put so much effort in to argue against it that you begin to think it's some kind of psychological defense. Having once been a fundamentalist myself, I guess I get that: I suppose they'd take it as a confirmation of evolution, and proof that everything they believe in is wrong, leaving them with nothing. Myself, given the long odds again it, I'd almost have to take extraterrestrial life to practically be proof of God's existence, but not many share my opinions. Do scientists ever discuss this kind of thing?

KRISTINE: When scientists discuss fundamentalists, we tend to discuss either the stupidity of their arguments or how to counter said arguments with reasoning and evidence. Evolution gets a lot more attention than extraterrestrial life, though if extraterrestrial life were ever discovered I suspect that knowledge would blow away more minds than evolution. Not to offend, but really, fundamentalism is pretty boring.

REPUBLIBOT 3.0: None taken.

KRISTINE: Scientists are interested in testing ideas and asking questions, which is pretty much antithetical to fundamentalism. Once you assume you know all the answers and tell me there's nothing I can do or data I can collect to possibly change your mind about something, it's just not an interesting discussion anymore.

REPUBLIBOT 3.0: I tend to agree. The first step on the road to wisdom - and wisdom is highly prized in the Bible - is to just admit “I don’t know” and then try to find or figure things out. There’s even some things that the Bible leaves really vague, which I presume is to sort encourage the believer to come up with their own conclusions. Conversely, Fundamentalism can frequently become more about attempting to force things to fit with your beliefs, and less about examining your beliefs. It’s problematic.

KRISTINE: Much as scientists have become "Godless Darwinist" strawmen to fundamentalists, fundamentalists have become strawmen to scientists, further reducing their interest. Again, it's hard to get too excited about a discussion when the other side already thinks they know what you think and aren't interested in actually hearing what you think. As a religious scientist I see both sides of it, so I know there's more nuance than most would inject into a discussion, but if anything that makes conversations more frustrating.

REPUBLIBOT: I know that frustration well. I remember going to a couple debates between Duane T Gish, and a random biologist-of-the-week. Gish - and I’m sure he means well - would generally win the debates because he relied on arguments that seemed to make sense, and he played the audience better.

Most of the audiences for these things were Creationists (As was I at the time), there weren’t a lot of the other side who showed up. The biologist would generally win on points, but would get trounced by their delivery.

Eventually, even I started getting a bit frustrated by the reliance on rhetoric rather than explanations.

KRISTINE: In the scientific discussions I've had concerning how unlikely life is to show up and evolve into us it's clear how miraculous it is we exist at all, but the scientific response isn't to attribute that to God, but rather to ask what conditions sparked us into being. There are a lot of really cool ideas out there, from the hydrogen hypothesis for the first eukaryote to the aquatic ape theory that tries (albeit badly) to explain why humans are hairless.

REPUBLIBOT: The Aquatic Ape theory is a fun one, but a lot of the reasoning is pretty tendentious. Assuming there is life out there, what's your opinion of how it evolves and propagates and flourishes? Are we assuming a totally independently originating biology every time, or some form of panspermia like you alluded to above, or some third option I know nothing of, or a combination of the above?

KRISTINE: That is a very interesting question. I think given how quickly life evolved on Earth it must not take all that long to evolve once the basic conditions are met. What those basic conditions are is still up for some debate, but you definitely have to have some environment that is sufficiently stable and protected to not destroy nascent life, but still chaotic and energetic enough to provide an energy gradient that can be exploited. I wouldn't be surprised if life evolves almost every time such conditions occur and persist long enough (again, what long enough is, I don't know, but I'd guess it's shorter than a million years), but getting beyond that is still a pretty difficult, I'm sure.

Whatever life lives in (like water) has to stick around for a while, and in a form that's still useful. Life can't either consume all available resources or foul its environment completely, or, if it does foul its environment, life has to figure out a way around that.

Oxygen is a prime example of a dangerous byproduct of metabolism life had to figure out a way around. Photosynthesis evolved fairly early (perhaps earlier than 3 billion years ago, according to some estimates), but photosynthetic organisms didn't become widespread for several hundred million years after that. About 2.7 billion years ago some organisms evolved the capacity to deal with oxygen, which is what allowed them to crowd out their oxygen-hating neighbors, and eventually to deal with an oxygenated atmosphere after about 2.4 billion years ago. Today, the Earth's surface is dominated by the descendants of those organisms that were able to adapt to the poison that is oxygen, relegating everything else to the environments that remained anoxic.

But getting back to your question, it's relatively easy for pieces of planets to move from one planet to another within a solar system. We know of several Mars meteorites, and although I believe we don't have any evidence for Venus meteorites yet, theoretically they should exist--we just have to figure out which rocks aren't really from Earth. So, the transfer part of panspermia we know is possible, and we know plenty of material has been ejected from our solar system into the cosmos. The real trick is keeping life alive for the hundreds of millions of years it'll take to travel to another planet without accreting into something uninhabitable, being irradiated to death, or simply never accreting anywhere.

REPUBLIBOT 3.0: Are there any authors or websites you can recommend for our readers who may be interested in looking at this subject in more detail?

KRISTINE: Carl Sagan's always a good read, both for his fiction and non-fiction, and I'd recommend both. If you want a more scientific read, check out Peter Ward's “Rare Earth: Why complex life is uncommon in the universe.” If you really want to know what cutting-edge research is going on, you should check out the NASA Astrobiology Insitute (NAI) website ( ) and look both at what's presented on that site and then what is presented on the personal research websites for people in the NAI.

If you want a less strictly factual but still educational take, I also really enjoy everything I've read by Kim Stanley Robinson. He writes fiction, but his research is impeccable! For me, he is the definition of hard science fiction.

After "Defying Gravity" was canceled I started re-reading his Red Mars/Green Mars/Blue Mars trilogy to get my journey to other planets/science soap opera fix. I'm amazed at how well it's aged. Sure, there are things we've learned about Mars in the intervening years, but it's clear when he was writing the books he was using the cutting edge research available. As an added bonus, his interpersonal relationships (a.k.a.--the soap opera) feel more believable to me, since I've know a number of his characters, albeit with different names.

REPUBLIBOT 3.0: I really should re-read those and review them for the site. But - ha! - that gives me the opportunity to make a segue to lowbrow science fiction mode: What's your absolute least-favorite, most-hated alien cliché that turns up again and again and again in Science Fiction? Something that, to you, screams "Total failure of imagination." For me, personally, it's the Entirely Monolithic Alien Culture - the "Race of Warriors" or the "Race of Poets" or what have you. That just drives me nuts, and I can't take it seriously. What drives you nuts?

KRISTINE: Oh, where to start! I hate PSA [Public Service Announcement - Ed.] episodes. I know, I know, science fiction is really an examination of us humans here on this planet at this time, but I really hate it when the writers of any science fiction beat me over the head with some extraordinarily "relevant" moral lesson. The addiction trope is particularly annoying, especially since in almost all PSA episodes the main character who becomes addicted never faces any real, lasting consequences, and it's never a problem again. In my experience, addictions don't happen so quickly, and they're never resolved so fast and with so few consequences. Likewise, genocide (especially if the perpetrators happen to be white, blonde-haired and blue-eyed actors) and racial/gender/whatever oppression are never handled very well, in my opinion. Yes, those are bad things, but I hate being pounded over the head with them. In reality, people's motivations for perpetuating abuses of any sort are never simple, never clear-cut. Most people don't realize they're doing something inappropriate or hurtful, and that's a subtlety that's too hard for Hollywood most of the time.

REPUBLIBOT 3.0: A very good point: Monsters very seldom realize they’re monsters.

KRISTINE: Being a feminist, the female oppression stories are particularly galling because they always seem to be saying, "look how backward people used to be, and look how much better we are now that we allow women to talk in public and have jobs. Feminism has really fixed things!" True, things are better. I now have the right to vote and own property. Good things. But sexism is still alive and well, if more subtle, and the only show I've seen tackle that in an even sort of realist way is Battlestar Galactica. Aaron Doral's reaction to President Roslin comes off as extremely sexist, but also very realistic--conveniently, since he turns out to be a Cylon.

REPUBLIBOT 3.0: Finally, what's your favorite science fiction aliens? For me, in literature, it'd probably be Lord Running Clam from Philip K. Dick's "Clans of the Alphane Moon." The book itself was mediocre at best, but Clam was a sentient Ganymedian slime mold, and he was just great. Far better than the material. On TV, it'd probably be G'kar from Babylon 5 - a bipedal marsupial reptile with a very, very complex personality.

KRISTINE: There are so many writers out there who've come up with alien races I love. I like basically every alien race imagined by David Brin, especially the Traeki--any group of organisms that communicates by smell just has to be cool. The Shrike in Dan Simmon's Hyperion Cantos is the creepiest, coolest non-human character--I definitely would not want to be on its bad side. One more writer--Vernor Vinge has written about some great aliens. Who would ever suspect cuddly, big-eyed bunnies of being deadly assassins?

REPUBLIBOT 3.0: And that's it. Thank you very much, I really appreciate your taking the time out to talk with us today! If you're up for it, we'd love to have you back in the future to discuss paleoclimatology, which is a subject of great interest to a lot of us.

KRISTINE: Thanks again!