Or at least very, very little. Observations made with the Tunable Laser Spectrometer on Curiosity (paper|press release) rule out an atmospheric level above 1.3 parts per billion with 95% confidence: the data is fully consistent with no methane at all. As the authors say:
Our result greatly reduces the probability of significant methanogenic microbial activity on Mars and recent methane production by serpentinization or from exogenous sources including meteoritic, interplanetary dust and cometary infall.
There will be some background from meteoritic sources, I assume, at the parts per trillion level (where I imagine they will stay undetectible even if Mars passes through the coma of comet C/2013 A1 (Siding Spring)). But these observations leave the idea of a methane-producing cryptic biosphere with no supporting evidence at all. This would feel like the end, if it didn't feel like things had ended a while back -- see this post and links therein. I rather regret that Mars looks deader still than it did before, but I don't regret having been so excited by the subject back in the day -- it's the nature of the game.
My only real loss is that I made a bet on the subject with Chris McKay, right at the beginning of the story, and consequently owe him a meal. But that loss is offset by the far greater gain of, hey, having a meal with Chris McKay.
And another gain is a greater appreciation of the power of theory. The observational case for methane on Mars was pretty good -- good teams, different techniques. The theoretical case against it, though, as brilliantly articulated by my friends Kevin Zahnle and David Catling and their colleague Richard Freedman in this article (pdf), was really persuasive. That insight has broader applicability, as I noted here:
Thomas Huxley, Darwin's ally in the fight to get evolution accepted, spoke warmly of the facility with which ugly facts can kill beautiful theories. But that fatal ability should not hide the fact that well-applied theories, beautiful and otherwise, can play a crucial role in deciding which observations get treated as facts in the first place.
Writing about something that is definitely unlikely, but the precise unlikeliness of which is uncertain, is an interesting thing. I assume the chances of Comet C/2013 A1 (Siding Spring) hitting Mars on my beloved niece Lucy's birthday next year are really low -- thousands to one or worse. But the possibilities that would be opened up if it did hit would be remarkable. Here's a post on the subject from The Economist's Babbage blog:
Update: as this later piece notes, the chances of an impact are now put at zero, though the approach might still be spectacularly close.A PAIR of middle-aged tourists (see previous post) are not the only thing headed for Mars. Comet C/2013 A1 (Siding Spring) is also on its way. Discovered on January 3rd, some calculations of its orbit, according to Phil Plait, the rather good “Bad Astronomer”, have it passing 37,000km above the surface of the planet in October 2014—roughly the height at which communication satellites orbit Earth, and a remarkably close shave by cosmic standards. An official NASA website puts the most likely “close-approach” distance between the comet and Mars at something more like 100,000km.
But the minimum close-approach distance is zero.
So following an NPR piece there's a lot of rumour going round about the possibility that Curiosity has found some organic molecules (Boing Boing, Emily's always excellent Planetary Society blog). If this is indeed the case, then it's interesting but not in itself epoch making. To some extent, since Viking, the surprise had been that there have not been organic materials detected.
As discussed in this post, thousands of tonnes of organic material arrive at the surface of Mars every year. Once it gets there, it either has to be got rid of or it accumulates. Recent work has also shown that most of the Martian meteorites studied have been found to contain organics that were aparently created on Mars through means that have no link to biology (Science paper here). So not only should people presume there are at least some organics on Mars -- people have actually found and studied organics from Mars.
Investigations by Viking and Phoenix did not detect organics, but that is consistent both with processes in the soil destroying them and the protocols used to look for them them being unable to succeed due to the presence of perchlorate (JGR paper here). Curiosity's SAM (Sample Analysis at Mars) instrument suite can look at samples in a wider variety of ways (the sealed cups with chemical solvents may be the key) and is looking at somewhat different environments so if they are there it might well see them.
If that's what's happened its definitely interesting, and I'm sure there will be stuff to be learned from the nature of the organics (for instance, saying if they are made-in-Mars like those in the meteorites or whether they got there from elsewhere). It would be a signal accomplishment. But in the absence of organic molecules that look suspiciously lifelike it would say nothing in itself about the likelihood of life. We don't assume that organics on meteorites mean that the asteroid belt is teeming with life. And it woud hardly be surprising. I certainly don't think it would be historic to discover that a surface on to which organic molecules ceaselessly fall has organic molecules on it.
If you don't believe me, here's someone who actually knows:
What’s the likelihood of finding organics? John Grunsfeld, head of NASA’s Science Mission Directorate, said he likes Curiosity’s chances. “If I had to predict the future, I would say it’s likely."
Well that was worth getting out of bed for! (I imagine; thanks to the iPad and NASATV I didn't have to bother). I don't think I have much to add to the general yawps of pride, joy, excitement, relief and so on; it was an amazing achievement, and a real thrill. But there's something to be said for taking opportunities to refresh oneself on the basics, which are often forgotten. "It's sometimes a struggle to know what you know," as my friend Ken puts it; as Donald Rumsfeld might have said, there are knowns that sometimes somehow get unknown.
The cost pendulum has swung all the way over. In the days when my Mars interests were at their peak, NASA was in full-on faster-cheaper-better mode. The cheapness carried the can for the loss of the Mars Climate Orbiter, the Mars Polar Lander and the Deep Space Two microprobes. This was not, I think, fully deserved. As I remember the inquiry MCO was lost because of poor management; anomalies were noticed but not hunted down. The MPL case was more complex; more money might have caught the bug that probably did it in. Either way, faster-better-cheaper went out the door. Curiosity has cost roughly 10 times what MPL cost. Rather than being one of a series of landers which, pre-MPL, were intended to fly at every quasi-biennial launch opportunity, it will quite probably be the only Mars lander this decade.
One ought to assume that the pendulum will now swing back. If you want to continue exploring Mars, you have to find a way to do it cheaper. In practise this probably means do not do it through JPL. JPL, as the world saw this morning, is magnificent. But it is also very expensive. I've talked over the years to various people who have tried to put together cheaper Mars missions. None of them could go through JPL and fit inside budget caps. JPL needs big missions, and fights hard for big missions (cf the saga of SIM). For this reason alone, a Mars lander not conceived at JPL would be a great thing. The "Red Dragon" concept from SpaceX and NASA Ames is obviously of interest here, not least because there's always the chance that if all his other businesses do well Elon might undertake it off his own bat. But other people, such as APL, might also get into the game (I've pretty much given up on ESA as far as this is concerned, but would love to be wrong).
One complicating factor here: longevity. The Curiosity entry, descent and landing (EDL) telemetry came back through Mars Odyssey, which has been in orbit more than ten years. Mars Express and -- amazingly -- Opportunity have been there almost a decade. No one expected that those missions would last that long. If Curiosity can operate interestingly for a decade, then it can basically *be* the program as a big sample return mission slouches towards Bethlehem.
But redundancy would be better. More missions can drive down mission costs -- for example through the reuse of EDL systems. I have no idea how much of Curiosity's cost went on EDL, but I bet it was a lot. And currently there are no plans to reuse the system at all. Indeed none of the successful EDL systems demonstrated on Mars have ever been re-used after their initial success (the MER systems were meant to be a reuse of the Pathfinder system, but they were so extensively redesigned as to be more or less de novo). Every time people go to Mars they find a new way of doing it. Those who have already succeeded get better at it -- this report by Eric Hand argues that thanks to experience, better knowledge of Mars and better software Curiosity's EDL was a lot less risky than many, including me, assumed. But it would be even easier if the same system were used more than once. And the whole enterprise would be better if people could buy such a system of the shelf, rather than tring to recapitulate the EDL-development expertise that has built up at JPL over decades.
America still has true interplanetary pre-eminence. Spending billions of dollars, maintaining continuity and inspiring great engineers does bring results, as the EDL success makes clear. I think I heard John Holdren tell someone this morning that no other country had landed on another planet, which isn't quite true; the USSR landed on Venus. Also Europe, with American assistance, landed on Titan, which is pretty planetlike even if it is a satellite, Japan landed on an asteroid, and the USSR landed on the Moon a number of times. But it is definitely true that no other nation has chosen to develop the capability to do things like land Curiosity, or build and operate Curiosity, and it's a pretty open question as to how easily any other nation could. This is much more difficult than simply repeating the feats of the 1960s, as the Chinese space program looks set to do for the next decade. For the time being, the trans-lunar solar system is the province of the United States, with a few allies just about in the game. [Update: This doesn't, though, excuse ignoring international naming conventions.]
There could be fossils. This is, I think, widely downplayed, and probably reasonably. But the odds that Mars once had life are pretty good. Life on Earth started early, and that means both that a) early starts for life on terrestrial planets are plausible, perhaps (depending on how much anthropic principle you feel comfortable with) likely and that b) in its formative years the inner solar system was littered with Earth rocks that had bacteria in them, many of which will have landed on Mars innoculating it through what I (but not enough other people) call transpermia. This is because big impacts knock small rocks off planets, and there were a lot more big impacts early on than there are today. Bacteria can remain viable in space for quite a while, and though the flow of rocks from the surface of the Earth to the surface of Mars would be a lot slower than the flow the other way (it's uphill, not downhill) it would have been appreciable.
If there was life on Mars, wet sediments from 4 billion years or so ago would be a good place to find fossils of it. Sediments on Mars are likely not to have been anything like as heavily reworked as sediments on Earth are. Microbial colonies can leave quite large macrofossils. Identifying them is not without issues: as the "Knoll criterion" has it, anything being put forward as a fossil must not only look like something that was once alive, it must also not look like anything that can be made by non-biological means. So I don't think fossils are a sure thing, or even likely, and I don't think, if there are fossils, that it will be easy or indeed possible to establish definitively that that's what they are. But my feeling is that the chance of seeing fossils is not that low (in the realm of a few percent more than in the realm of a few chances per million) even if they are not incontrovertibly recognised as such.
Science won't get people to Mars. In the understandable enthusiasm people are talking of Curiosity as a pioneer for future human exploration. Not so much. Science has never been a driver for human spaceflight. Science was an add-on to Apollo (a great add-on, needless to say) and after that, well, the space station? Really? What's more, sending ever more capable rovers reduces, at the margin, the case for sending scientists (unless, perhaps, they find something both fascinating and flummoxing -- see above). Opportunity and Spirit took months to match the output of a lesiurely few hours of human field geology. Curiosity should be more impressive that way. I'm not remotely saying that there wouldn't be much more for well equipped human scientists to do; just that, at the margin, the case for them shrinks a bit.
There are, I think, two ways that people get to Mars. One is a big national/international prestige thing for which there is currently no driver. The other is that technology and continued virtual presence on Mars tips the question from "Why go to Mars?" to "Why *not* go to Mars". Wanting to know more about Mars will play, at best, a minor role, though it will benefit hugely from any such endeavour.
[Updated a little to correct some of the typos, lest neophyte blogger Geoff Brumfiel be set a bad example]
I got a lovely email the other day from Leo Enright, friend of this blog, wondering whether it was going to come out of its long hibernation for the MSL landing. Well probably not. I'm not at the landing (having been part of the party for Mars Polar Lander and for Beagle 2 (full archive), I have a suspicion that I'm something of an interplanetary Jonah). And much though I love it, Mars is no longer really part of my beat. But in honour of Leo's request, I thought I'd put a couple of articles from the past few years that are of Martian interest up. Here's one on MSL specifically, and here's one on methane. And if I get carried away in the excitement of this great achievement (or feel the sad need to deliver a post mortem) then -- who knows -- I might even add some fresh stuff. (I won't change the look of the blog: it's going to stay antiquated/charmingly retro).
One thought in passing. It is truly incredible that Curiosity will land while Opportunity is still sending back data. No one would have imagined that possible back in '03. No one. What a triumph.
What blogging I do these days is over at Heliophage, which started off as a blog for my book Eating the Sun (Amazon UK|US). You may find something of interest over there if you're keen on carbon/climate stuff, my idea of nature writing or (my main focus at the moment, away from my day job) geoengineering, among other things.
Other stuff goes on twitter: @eaterofsun
I wrote this column for Intelligent Life, The Economist's sister magazine, at around the time that MSL/Curiosity took off last year. In setting the scene for the landing, and the new phase of Mars exploration that comes with it, it also serves as a precis and update of some of the thermes of Mapping Mars (Amazon UK|US):
Mars to within a metre
It is a desert plain, caramel-smooth and windswept-empty. To its north rises a mountain taller than Mont Blanc, Mount Rainier or Fuji-san and though, because it is also wider, its sides are less steep and prospects less dramatic, it is still an impressive thing. A massive central shoulder, banded with rocks of different ages, juts out over the plain; to its side, the mountain’s forest-free flanks are cut with canyons. The summit—whittled away by the wind but a stranger to snow—sits farther back, hidden from view. Both plain and mountain are ringed by a wall four kilometres high and almost 500 kilometres long, the rim of a crater the size of Wales. Above the landscape is a washed-out, alien sky. At the right time of year, the Earth hangs over that horizon-rim at twilight, a blueish evening star.
This is Gale crater, a part of Mars with which some of the inhabitants of that evening star have made an appointment. As this page went to press in late November, a six-wheeled rover called Curiosity was due to be thrown there by a 500-tonne Atlas V rocket. If all goes well—a substantial if, as Mars missions often don’t; a Russian one failed to get beyond Earth’s orbit in early November—then next August a complex system of parachutes and retrorockets will lower the rover through the thin Martian atmosphere to its destination. It will trundle across the plain to the ancient rocks of the mountain’s base and start a slow ascent. It will sniff the air and take samples of rock and soil to analyse in its on-board laboratory. With the help of an orbiting intermediary, it will send back to Earth a torrent of pictures, from the panoramic to the microscopic.
Curiosity’s climb up that still unnamed mountain [un-named no longer: now it's
Mount SharpAeolis Mons] promises an extraordinary return in terms of science (and with a price tag of over $2 billion, so it should). It also opens up a new era of exploration—so new, in fact, that it may no longer be exploration at all.
Read the rest here
And here's an archive of all my "Music of science" columns.
One of the early results I think we're expecting from Curiosity is an analysis of trace gases in the Martian atmosphere -- including the level of methane. There was a time when I, and this blog, were obssessed with the news of methane on Mars and what it meant for the likelihood of a cryptic microbial biosphere in the Martian subsurface (full archive). Indeed it is possible, I can't say for sure, that I may have been the origin of the martian-methane-expressed-as-a-number-of-cows meme found recently in an excellent piece by Dick Kerr (summary|paywalled full text). In the excitement, and newly enamoured with the fun of blogging, I was quite the believer.
More recently I have become more sceptical, very largely as a result of this article (pdf) by my friends Kevin Zahnle and David Catling and their colleague Richard Freedman. My take on the article and its arguments, by which i was and remain broadly convinced, appeared a couple of years ago in The Economist. I won't recap it here, but if you're interested it's worth a look. And I liked the conclusion:
The debate carries a worthwhile scientific lesson in itself. Observations, which to an outsider might sound like simple things, are often remarkably difficult, and depend on complex models to make any sense at all. Thomas Huxley, Darwin's ally in the fight to get evolution accepted, spoke warmly of the facility with which ugly facts can kill beautiful theories. But that fatal ability should not hide the fact that well-applied theories, beautiful and otherwise, can play a crucial role in deciding which observations get treated as facts in the first place.
Pretty soon after landing, insha'Allah, we should know whether the level is in parts per billion or parts per trillion. It may, indeed, be one of the mission's crucial results (unless something satisfies the "Knoll criterion"...)
The one-way-to-Mars idea has been around a long time, and as someone who ended his book on Mars with a section on the various ways in which making the voyage to that particular "other world" could be seen as chiming with the idea of making the voyage to the undiscover'd country of death I have a sense of why it might appeal. But even when it is championed by someone as smart as my friend Paul Davies, as is the case in today's Guardian, it is still a silly idea. Here are extracts from Paul's article with my comments
Well you can make do without a return vehicle, sure. At the same time, you have to take or pre-position four years of supplies if you are to keep a straight face about "not talking about a suicide mission" -- two years to take you to the next resupply mission and two years to deal with the possibility that that resupply mission might fail. You have to take either more shelter or more tools for building shelter. You have to take a long term power supply -- either a lot more photovoltaics than a short-term mission needs or a nuclear reactor. Again, if you are to say "not a suicide mission" with a straight face, back-ups for everything. And you still need to design a wholly new, large capacity entry, descent and landing system, which is a big challenge, and sort out how to stay ready-to-explore healthy on the trip out. The idea that leaving out the return vehicle could in itself reduce costs by 80% seems extremely farfetched -- even more so when your plan includes prepositioning the supplies and food. Why not preposition the return vehicle too, a la Mars Direct? Would that really increase the costs fourfold?
Most importantly, in terms of costs, there's the ongoing commitment. A set of Mars missions you can cancel is a much more attractive proposition than a set of Mars missions that you cannot cancel without killing people ("Launch the next rocket or the kid gets it"). To fund a single one-way-to-Mars mission is more or less to sign up to funding them for as long as the colony lasts. That is a far larger spending commitment than required for a small number of return trips.
(Minor aside: no-one cares more about methane on Mars than I do: but does it really make Mars more habitable?)
This carries a whiff of the idea that the colonisation is being done by underpants gnomes (not a bad idea: they'd use up fewer expendables), with "profit" in the archetypal UG business plan replaced by "self-sustainability". How and why should we believe that the colony would become self-sustaining? And how much extra investment would that take? It is worth noting that Antarctic colonies, 50 years on, are not self sustaining. And Mars is a lot tougher. Not saying it couldn't be done -- but it doesn't sound cheap. You have to keep resupplying for a century at least, probably at an increasing rate for much of that time. If aiming for self-sustainability were a useful goal in such circumstances, we would be trying to make McMurdo self sustaining. We're not.
And that's before we get to the pregancies. No one at present has any idea of what it might take to carry a child to term under Martian gravity, or whether a non-engineered human can actually do such a thing successfully. That's a pretty big known unknown to sweep under the table. Is the plan for people just to get pregant and see what happens?
Yes, it might -- if the colony has the capacity to get them out from the depths at which they probably live (ie heavy-duty mining equipment). But the colony would also fatally compromise any possibility of making the research biologically reversible, which carries a strong environmental penalty over and above the fact that the contamination involved might make all that science a little hard to do.
I accept that arguing from science fiction is not ideal, but bear in mind the early Larry Niven stories in which Mars is an unexplored backwater largely because asteroid miners see no reason to ever descend into a gravity well. If asteroid mining ever makes sense, wouldn't it make most sense to target near-earth asteroids, of which there are plenty, rather than main belt asteroids? (Also, I suspect that in terms of travel time rather than delta v the average main belt asteroid is not that much easier to get to from Mars than from Earth orbit, but I may be wrong)
Really? All humanity? A cataclysm that would mean that the earth-bound survivors were fewer in number than a colony on Mars suggests to me either an extraordinarily thorough-going cataclysm or a really large colony on Mars, and neither of those seems very likely. Certainly seems beyond the power of war or disease, and I'm not sure even Chicxulub could do it (New Zealand flora were not hugely affected by the K/T event). Also note that having detoured through the Mars-as-a-trading-partner idea, we have now returned to the Mars as self-sufficient outpost idea -- a Mars robust enough to have all links severed is a Mars less reliant on earth than the Greenland colonies were on Iceland and Scandinavia. (Also, there's a philosophical point here: if all but a handful are dead, does the continuation of the culture as an idea really matter? Is it that much more than its instantiation? And does the answer to this change if the genocide was self inflicted?)
Leaving aside that our species didn't walk out of Africa (a few did, a lot stayed), the symbolism here is terrible. While Paul is definite that this would not be a suicide mission, it would involve a great deal of death and a high risk of total failure (especially if being done on the cheap). As Paul says, there will be "reduced life expectancy due to radiation, lack of advanced medical resources" as well as a very high risk environment: as Greg Benford once put it to me "Like the moon, but with worse weather". I was going to write at this point that human sacrifice is not an acceptable instrument of policy, and then realised that of course it is. But in such a blatant form I can't see it flying. The fact that there are plenty of people who might volunteer, as Paul rightly says, does not mean that it would be right to indulge them.
And what if they live? They do so because of unparalleled spending. A world where a select few gets hundreds of millions, at the very least, invested annually merely to keep them alive while equally deserving people die in large numbers for want of far less is not a very attractive place.
Human Mars exploration is indeed a fine goal, and it is quite possible that fairly early on there will be some who elect to stay. But the only real argument for doing it sooner or rather than later is the selfish one of wanting to see/participate in it personally. I can appreciate that, but I don't think it's a compelling policy point. There are a lot of other big exciting projects to inspire us -- a new energy infrastructure for the world, the millennium development goals, in pure science the development of telescopes for characterising the atmospheres and possible biospheres of exoplanets.
There is something poetic about the notion of death on Mars, or of choosing to die there -- Clarke's Transit of Earth caught that nicely. But Liebestod is not a good basis for public policy.
(This post doesn't mark any long term intention to start blogging here again in a serious way; I am in fact somewhat surprised to find myself putting it up, since there has been so much good stuff about Mars I haven't blogged. I guess I felt I had something to say. More frequent, less Martian blogging can now be found over at Heliophage.)
Just an update, in part because this is a page to which Google likes to send people who are looking for Oliver Morton.
Big news: Eating the Sun, my book about photosynthesis, has just been published in the UK.
You can read a little about it in this post on my other blog, Heliophage.
Heliophage is not, I fear ever going to have the sort of care and attention I gave this blog during its glory days of Beagle 2 and the Martian methane, but I do intend to keep it going with any news about the book, reviews of the book, or ideas relevant to the book that I can find time to blog about. (Since its the contention of the book that more or less everything is relevant to photosynthesis in some way or other, it's the time not the ideas that will be the limiting factor there.)
Rather pleasingly, in its first week Eating the Sun was named as one of the ten best nature books by The Independent. They didn't supply the list online, so I did so in this post (10 best nature books)
Eating the Sun is to date available only in the UK; the US edition is not expected until next year. But Amazon.co.uk, who do the best price I've seen so far, will undoubtedly ship it should anyone beyond these shores want an early copy.
On other matters. I'm still Chief News and Features Editor at Nature, and can be found now and then on Nature's Climate Feedback blog, and also very now and then on its new Great Beyond blog. I'm meant to also appear occasionally on First Drafts, the blog run by Prospect, but don't hold your breath.
As mentioned before, when I was explaining the silence on MainlyMartian, if you're a friend, associate or indeed enemy who has lost track of me, perhaps due to the interruption of my abq email address, you can reach me via gmail as oemorton, or at nature.com as o.morton.
We now return to our usual lack of programming