Remember the discovery of methane in the martian atmosphere? Now scientists can't find any evidence of it, at all

Remember the discovery of methane in the martian atmosphere? Now scientists can’t find any evidence of it, at all
Artist’s impression of the Mars Express spacecraft in orbit. Credit: ESA/Medialab

In 2003, scientists from NASA's Goddard Space Center made the first-ever detection of trace amounts of methane in Mars' atmosphere, a find which was confirmed a year later by the ESA's Mars Express orbiter. In December of 2014, the Curiosity rover detected a tenfold spike of methane at the base of the Gale Crater, and uncovered evidence that indicated that Mars has a seasonal methane cycle, where levels peak in the late northern summer.

The existence of gas on Mars has been long been held to be potential evidence for the existence of past or present life. So it was quite the downer last week (on Dec. 12th) when the science team behind one of the ESA's ExoMars Trace Gas Orbiter (TGO) spectrometers announced that they had found no traces of methane in Mars' atmosphere.

The announcement came during the 2018 Fall meeting of the American Geophysical Union, which took place from Dec. 10th to 14th, in Washington, D.C. At a presentation titled "Impact of the 2018 global dust storm on Mars atmosphere composition as observed by NOMAD on ExoMars Trace Gas Orbiter", the science team behind the Nadir and Occultation for MArs Discovery (NOMAD) spectrometer presented results from the mission.

Arriving in orbit around Mars in 2016, one of the chief aims of the TGO mission was to scan the atmosphere for signs of methane. This task has been performed by two of the orbiter's spectrometers – the NOMAD and the Atmospheric Chemistry Suite (ATS) – which were designed to detect methane in very low concentrations.

Given these instruments' sensitivity, the science team was confident that if there was any methane to be found in Mars' atmosphere, NOMAD and ATS would be able to sniff it out. However, the team's initial results showed no detection of methane all the way down to the surface of Mars, even at the minute level of 50 parts per trillion.

Remember the discovery of methane in the martian atmosphere? Now scientists can’t find any evidence of it, at all
This image illustrates possible ways methane might get into Mars’ atmosphere and also be removed from it. Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

According to Ann Carine Vandaele, a at the Royal Belgian Institute for Space Aeronomy and NOMAD's principle investigator, their is still background noise to clean up from the results. However, both instruments are in working order and there appears to be no reason to doubt these preliminary findings.

According to Chris Webster, a planetary scientist at the Jet Propulsion Laboratory who leads the methane-sensing instrument on Curiosity, the previous levels detected mean that the TGO should have picked up a signal indicating a methane level of at least 0.2 parts per billion (ppb). Nevertheless, there are reasons to remain hopeful.

For one, there is the matter of the hundreds of tons of organic carbon that are believed to pour into the Martian atmosphere every year from Solar System dust. Scientists have theorized that this carbon reacts with solar radiation to form methane. If there is in fact no methane in the atmosphere, then where this carbon is going is a mystery.

Second, from what they have found in the past, Webster and his team suspects that Mars' methane cycle comes in "microseeps" from subsurface sources (either from living or geological in nature) – and not from outside the planet. The TGO results could be seen as a validation of that, since it found no trace of methane falling down through the atmosphere.

In addition, it took the Curiosity team 6 months to detect the tenfold methane spike in Mars' and years to detect the background methane cycle. So Webster strongly believes that finding the Martian methane is just a matter of time. "I'm confident that over time there will be a consistency between the two data sets," he said. "The methane is not coming from above. That's a big result."

Naturally, Vandaele and her team still need to process the NOMAD data and further scans will be needed before these results can be considered definitive. And given the many previous instances where methane was detected, it seems unlikely that all the previous results were in error. Like the existence of life on Mars, the matter of the "missing methane" is likely to remain a mystery for the time being.

Explore further

Interpreting new findings of methane on Mars

More information: Impact of the 2018 global dust storm on Mars atmosphere composition as observed by NOMAD on ExoMars Trace Gas Orbiter … app.cgi/Paper/350159
Citation: Remember the discovery of methane in the martian atmosphere? Now scientists can't find any evidence of it, at all (2018, December 21) retrieved 15 October 2019 from
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Dec 23, 2018
I have been very rude disparaging the speculations & assumptions that Mars has to have some sort of life skulking about.
Whether native alien, interstellar alien or transplanted Earth Life.

I tentatively agree with the speculation that industrial-level prospecting might discover fossils of very primitive Archaic Martian native alien lifefoms, extinct.
Buried very deeply.

Otherwise? Considering all the rock booted off of Mars. Retrieved here on Earth? Yet no Martian fossils.

If you want to disagree?
Cause it is obvious to you, the Martian coprolites were burned up & destroyed upon slamming into the Earth's atmosphere?

I'm going to let you explain that reality to the panspermia nutjobs. They are such a tiresome lot of comicbook fanatics.

However, I would caution you. The assessment by these researchers "That they did not detect Methane loose in the Martian atmosphere."

May be true by this experiment but not true by the next experiment.

Dec 23, 2018
For starters, finding fossils of any sort on Earth is hard enough, and that's in spite of confirmed billions of years of life all over our planet's surface. Secondly, differentiating between microfossils and purely geological phenomenon can actually be very difficult, particularly with samples where we cannot take life for granted; you could easily have a sample and never be able to confirm whether it's biological or non-biological in origin. Lastly, the inventory of suspected Martian meteorites on Earth is a scant 214, and only one is old enough to have been ejected when Mars had significant bodies of water on its surface and thus most likely to support a surface biosphere.

The vast majority of Martian meteorites would have arrived long ago and have long since been completely annihilated by Earth's erosive forces. Contrary to your uneducated accusations, we're unlikely to recover easily verified, "martian coprolites" in even the most optimistic circumstances.

Dec 23, 2018
I want to thank you Scholar for so clearly restating my cogent points.

& I want to reassure you that I appreciate how tolerant you have been of my juvenile humor.

& yes, yes. I am a satirist.
My motto? "Science is fun!"

"If you cannot laugh?
You must weep..."

Humor is an important method of how to separate Real Science from the stifling crankery of the fakirs of superstition & the fraudulent woowhooey merchandisers.

Dec 23, 2018
"Gee, that's funny."

The prelude to many interesting scientific discoveries.

@rrwillsj, perhaps "coprolites" was a bit over-the-top.

Dec 23, 2018
The only, "points" you made were straw man example of what astrobiologists would expect to find and characterize anyone who so much as entertained the possiblities as, "comicbook fanatics". Those are hardly cogent, and now you're visibly backpedaling it into some kind of souvenir argument. That's hardly appreciation and more like a poorly designed attempt at a backhanded insult.

Really, though, "It was only satire!" is about as effective a palate cleaner as that other trite idiom: "Bless their heart!". It's pretty easy to look up your previous unrepentantly obnoxious behavior, and trying to make it out like you're secretly just trying to be funny the whole time is in and of itself hilarious.

Dec 24, 2018
@Visari, with people on this site seriously proposing that telepathic alien lizards are posting articles on the scholarly literature, and that there is no gravity, it's all EM (see Electric Universe), sorry but I see @rrwillsj as pretty benign. Maybe you should take a look around and see what's happening here. I don't see much problem with people throwing stuff out there to see if they get a valid argument discrediting it as a problem; it's the psychotics who insist that we all need aluminum foil on our windows that are the real problem.

Dec 24, 2018
ahhh, scholar, I can see what the disconnect is now.

Silly, me. I had assumed that you were criticizing the ambiguity of my humoresque opinions.

Now I understand, you are resenting my ridiculing your cherished belief in pseudo-scientific fabulism.

Well sonnyboy... DUCK!
This cream-pie is aimed at you!

Your infantile stuporstitions & woomerchandising...
On a Science Site?

Makes you fair game for me channeling Soupy Sales & Imogene Coca (I'm versatile!)

Whine all you want, boi. While I go dig around my storage for a seltzer bottle.
Hey! There's my Official Ed Wynn Rubber Chicken! & whoopie cushions!

Dec 24, 2018
The very last of the sand worms has died.

So sad.

But now the planet is ours.

Dec 27, 2018
Mars Needs Women!

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