MainlyMartian

Or rather, no ammonia

This weekend I heard something that made me considerably more dubious about the ammonia story, and which fits pretty well with the article by Stephen Strauss in the Globe and Mail that Alex Blackwell (Hi Alex) linked to in the comments for the previous post.  Strauss reports that ESA denies categorically that PFS has detected ammonia, to the point that the agency's spokesman, Guido De Marchi, said bluntly "it's a hoax". The BBC told Strauss that they stood by their story.

So at this point, it's not entirely clear what if anything Vittorio Formisano, the principle investigator on the Mars Express Planetary Fourier Spectrometer, said or meant to say to David Whitehouse, the BBC reporter. It's certainly possible that he may have said something ESA didn't want him to have said. After all, while Mr Strauss reports the ESA spokesman as saying "The instrument aboard the Mars Express has not looked for ammonia", in an earlier interview with Lynda Moulton Howe, published  on her website a couple of months ago, Formisano is clearly quoted talking about benzene, formaldehyde and ammonia as targets being searched for. So either Formisano was misquoted in that interview, or his answers were misleading, or the ESA denial over-reaches. It may be, for example, that different factions in the PFS data-analysis team are reaching different conclusions, and ESA officialdom is on the conservative side. And if so they may well be right to be there; as mentioned in the last post, ammonia is a really tough identification for a system like PFS.

In general, that web interview seems consistent with Whitehouse's story, giving the impression that Formisano might have thought he was finding something but wouldn't talk about it as yet. The interview also gives the impression that he's more willing to speculate freely on life as a source of trace gases than I have found him, though I wouldn't claim he's ever opened up to me that fully. (Some readers may want to take on board the fact that Lynda Moulton Howe has a track record in writing about crop circles and cattle mutilation. On this matter I'll report and you can decide.)

If Formisano were a source for David's story, one might imagine he'd said something ESA, and quite possibly also his PFS colleagues, didn't want him to say, and the agency is now engaged in what it sees as damage control. But looking again at David's story, it's not clear that Formisano was a source (and according to Strauss, ESA says he wasn't). Indeed it's not clear who any of the sources are -- they're all anonymous "researchers"; the only one quoted directly is just a "US space agency (Nasa) scientist".

The only clearly discernible basis for the story is Formisano's abstract (pdf here) for this week's Cospar meeting in Paris, which says "The high spectral resolution [of the PFS] allows us also to identify a number of small signatures which possibly will bring us to the identification of minor compounds (at the moment a good candidate is ammonia)." David didn't specifically cite or quote that abstract in his story, but the BBC pointed to it when Strauss at the Globe and Mail asked them if they stood by the story. Again, that makes ESA's "never looked for ammonia" hard to believe, and Strauss quotes ESA backing down a little, saying there had been plans to look that weren't followed through on.

At the same time, it's a pretty tenuous basis for the BBC story; that abstract doesn't sound to me like a "detection", even a "tentative detection", nor does it sound like "evidence for the gas was seen by". You'd really have to hope that David -- who I know on casual but friendly terms -- was working with more than that abstract and some responses from other researchers not directly in the know. Surely a story like this needs comment from one or more of the PFS workers (especially if there's dissent in the team). Strauss, at the Globe and Mail, says he got no response when he repeatedly called David to ask him about this. Maybe the comments section here will be luckier.

In short, it doesn't look like we should expect anything ammoniac at Cospar this week. Indeed, David's comment on the previous post suggests as much. A pity, since as Rick Sterling pointed out in another comment, David's story if anything underplayed the significance of ammonia. According to an email from Mark Allen of JPL that's up on the web here "At present there are no known abiotic processes that would result in ammonia being present in the atmosphere without the existence of life." Allen knows a lot about this, as he is the principle investigator on the proposed Marvel mission to measure trace-gas abundances, a mission I talked about a little in this post on next steps for methane detection. (And in the dog-that-didn't-bark category, I wonder why Formisano's abstract says nothing about methane, since that's obviously the big PFS story so far; maybe the abstract was submitted a very long time ago. Intelligence from anyone who's actually at Cospar most welcome)

Given all this, I think I'll avoid talking about the tangled history of the possibility of formaldehyde, which Formisano also mentioned in that web interview, for the time being. A pity, since it means passing up some more perfectly good dead shark jokes.

Correction: When I first posted this entry I mistakenly typed "methane" for "ammonia" at a crucial point, as Alex Blackwell notes in his comment below. To avoid confusion I fixed the mistake.

Ammonia

At BBC Online David Whitehouse is reporting that the Mars Express PFS is going to report the detection of ammonia in the martian atmosphere at the COSPAR meeting next week. Obviously very exciting if the observations stand up; ammonia would be very unstable in the martian atmosphere and so would have to be constantly replenished, or if only present intermittently produced in contemporary fits and starts. It could clearly come from a biological source -- if Mars life is remotely like earth life it needs a nitrogen cycle. And the abiogenic sources of ammonia are probably scantier than those for methane: no serpentinisation, and no clathrates, I think (though ammonia can be mixed into water ice). So ammonia could be a strong signal of life.

But there are reasons to be a good bit more cautious about this detection than the methane detection (about which one should also be moderately cautious, though I must say I haven't been). The most important difference is that in the case of the methane, the news was particularly exciting because three different teams using a number of different instruments all seemed to see compatible results; here there is only one team reporting anything. Like the methane results, this ammonia result hasn't been published yet, and other scientists elsewhere haven't even seen the spectra at conferences yet. Indeed, as far as I know, the PFS team hasn't published results on anything as yet, and so there's no way for outside experts to assess the fine details of the ways in which they're analysing their data. As David notes in his piece, "[members of the PFS team] are still coming to terms with the complexities of the PFS as well as coping with some nagging power problems on Mars Express."

By a slightly freakish coincidence, I read the news while sitting next to Michael Mumma of NASA Goddard, one of the original methane observers (and thus, in some senses, a PFS competitor, though also a fellow striver after truth). Mumma -- who tried to detect ammonia in the martian atmosphere with earth-based instruments a few years ago, to no avail -- was clearly intrigued, but pointed out that if the ammonia detection was at ten microns (which the BBC report doesn't quite say, but which would be quite likely) then it would be very close to a quite striking carbon dioxide feature, and that if you were using a comparatively low resolution spectrometer such as PFS you'd want to be very careful indeed to make sure that the two bands weren't getting mixed up. Make of that what you will.

So if confirmed -- or simply published and scrutinised and found highly plausible -- this is extremely hot stuff: right now a very interesting thing to keep an eye on.

Incidentally, here in Iceland there is a delicacy called hakari made by burying sharks and leaving them to rot. Apparently it smells quite strongly of ammonia. Since Mars's ocean, if it has one, is undergound, it stands to reason that its sharks come ready-buried, and will thus be a potent ammonia source. Yet another way in which Mars is just Iceland writ large...