Search for Mars life stymied by contamination threat

October 1, 2015
This image released by NASA on February 7, 2013 shows a self-portrait of NASA's Mars rover Curiosity
This image released by NASA on February 7, 2013 shows a self-portrait of NASA's Mars rover Curiosity

A multi-billion-dollar robot dispatched to Mars to search for life must steer clear of promising "hot spots" for fear of spreading microbes from Earth, NASA project scientists said Thursday.

The spectre of a missed opportunity was thrown into sharp relief by smoking-gun evidence unveiled this week that liquid water, a prerequisite for life, existed not only in a distant Martian past, but is likely there today.

"Curiosity isn't designed to go to a place that can currently support microbial life," said Michael Meyer, a scientist for NASA's Mars Exploration Program.

"For that we need a higher level of cleanliness," which is more complicated and costly to achieve, he told AFP.

This exasperating reality was the result of a fateful decision years ago to forego NASA's most stringent microbe-removal standards for hardware visiting the moist environments in which Martian life—if it exists—will probably be found.

The danger of letting Curiosity investigate the newly-found sites is real, space scientists and astrobiologists agree.

"We don't want to be remembered as the species that went to another planet and wiped out whatever life was there," explained Jorge Vago, a scientist with the European Space Agency's (ESA) ExoMars Project, due to send it own Mars orbiter up in 2016 and put down a rover in 2018.

Scientists announced Monday they had found tracks formed by hydrated salt crystals—essentially super-salty brine—running down steep slopes on the surface of the Red Planet.

NASA's Curiosity rover, a car-sized mobile laboratory parachuted into the Red Planet's Gale Crater in August 2012, is especially well-equipped for microbe-hunting in just such an environment.

Its core mission is to gather soil and rock samples and analyse them "for organic compounds and environmental conditions that could have supported life now or in the past," according to NASA.

But the streaks, dubbed "recurring slope lineae" (RSL)—possibly the best chance yet of finding Martian life—are off limits for one simple reason: Curiosity is too dirty.

So close, so far

Adding insult to injury, the first spacecraft NASA landed on Mars some 40 years ago, dubbed Viking, met the highest cleanliness requirement, even if it never had the same golden opportunity to detect life.

"The missions we have sent since Viking have not been cleaned to the same level—Viking was essentially sterile," said Catharine Conley, who heads NASA's office of planetary protection, set up to prevent cross-contamination between Earth and the Solar System's other heavenly bodies.

"It would be very nice to have that capability again, to be able to drive right into the RSLs and sample (them)," she added.

Beyond NASA's even more stringent standards, space agencies are bound by an international treaty to "avoid harmful contamination" in space exploration.

Earth bacteria hitching a ride on spacecraft "could under certain circumstances find conditions (in which) they could prosper. That's a no-no," said Vago.

"We also try to kill all the bacteria on these probes so that we don't wind up... embarrassingly discovering life on Mars only to realise that it's our own dirty fingerprints," added Conley.

Money, money, money

Sterilising a space-destined probe to the safest level is expensive.

And when Curiosity was designed, well before its 2011 launch, chances for an inter-planetary meeting of species seemed more remote than they do today.

"We had not yet confirmed the presence of surface water on Mars," noted Jim Watzin, the director of NASA's Mars Exploration Program.

"Curiosity was designed to follow up on earlier NASA rover findings that had determined, via geology, that the surface of Mars had significant bodies of water in its ancient past, but not in the present," he told AFP by email.

Another factor was that the techniques used to sterilise Viking's hardware—essentially baking it at a high temperature for several days—would damage or destroy electronic equipment on newer designs like Curiosity.

But the mobile lab can still use remote sensors to gather information on the RSLs from a distance, said Watzin.

"It is a question of budget and priorities," noted Conley. "If you can do interesting science at a lower budget, people will tend to prefer that."

NASA's next mission to the Red Planet, Mars 2020, was also not designed to super-clean specs, Watzin said, and making a change now may cause unacceptable delays.

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23 comments

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wduckss
1 / 5 (5) Oct 01, 2015
It should not overwork in the search for life on Mars, because there is little chance of finding a (insignificant). Mars is a large desert area, which further removes the possibility of finding life.
It is more appropriate to accept the reality, Mars is a young planet, life would arrive someday.
Osiris1
1 / 5 (4) Oct 01, 2015
Our scientists are gonna have to realize that space is not really empty; and no matter how much they work 'cleaning' hardware that gets sent to that rock, contamination could still lurk from some 'forgotten' corner or 'we assumed the other guys cleaned that', or just got picked up in transit from some life carrying dust run into in space. Panspermia is gonne be found to be real. Space is full of life. And we will have to accept that the only tools we have are among DNA and RNA and other intracellular object analyzers. Life off world will probably have differing DNA in varying ways, or it may be more similar than we would care to accept. For if life obeys the same rules everywhere as Dr Steven Hawking suggests, we could be in for a bad time as we venture forth into the great black void. "Heavenly Father Strong to Save!", the Navy Hymn, will likely be sung often for unexpected reasons. One day we WILL be contacted by someone. We need to progress ...fast!! Look at da Ceres pix
bschott
3 / 5 (4) Oct 01, 2015
"We don't want to be remembered as the species that went to another planet and wiped out whatever life was there,"


How do you think we will be remembered when we're done with this one?
antigoracle
1.9 / 5 (8) Oct 01, 2015
Curiosity isn't designed to go to a place that can currently support microbial life

Hmm... wasn't the plan to look for life?
Physbiz
3.8 / 5 (4) Oct 01, 2015
There will never be a 100% clean machine on the surface, nor has there been since the beginning of Mars exploration; I'm really not understanding the point of this. The current and planned rovers lack basic compound microscope magnification even if we were able to get up those steep slopes and check out RSL for signs of life.

It's going to take boots on the ground and we are walking microbe factories able to both sample and determine origin; so what's the issue here?
Bongstar420
5 / 5 (1) Oct 01, 2015
DNA test will be conclusive. Contamination is already now
thelizard
3.3 / 5 (3) Oct 01, 2015
Wouldn't Earth microbes die when exposed to the radiation that hits Mars? The atmosphere is thin
And, it doesn't make much sense that NASA didn't consider the possibility of finding water-> life. They're already sending this machine all the way to Mars, might as well make sure it's clean.
LariAnn
1.7 / 5 (6) Oct 02, 2015
So we knew how to make Viking clean enough, but decided instead, - "Let's just spend all this money to look at rocks and not bother looking for life". We have the perfect logical excuse, too! That's all fine and dandy if you are spending your own money, but when you use taxpayer money for this, it should be of interest to everyone, not just a minority of rockhounds. Indigenous Martian life forms is what everyone has been waiting for, not more rocks and dust.
antialias_physorg
5 / 5 (9) Oct 02, 2015
Wouldn't Earth microbes die when exposed to the radiation that hits Mars?

Not necessarily. There are quite a number of microbes that can tolerate high radiation levels.
The atmosphere is thin

Microbes have been found in the upper atmosphere of Earth (where air pressure is similar)
And, it doesn't make much sense that NASA didn't consider the possibility of finding water-> life.

They did. But as the article noted: It was a cost issue.
Also they weren't sure to find water. Sterilizing the craft would have meant to omit a lot of other scientific instruments. In that case it would have been a complete gamble which might have ended in no science being done at all.
So they chose the safe route: search for water, do other science as well...and if water is found then build on that with a life searching mission the next time (or as it turns out the time after that)

Slow and steady. It ain't Hollywood - but unlike Hollywood: it works.
Torbjorn_Larsson_OM
4.3 / 5 (6) Oct 02, 2015
@wduckss: "Mars is a large desert area".

That Mars wasn't (had an ocean) and isn't the desert area that Viking seemed to imply is the advancement of 4 decades of hard work. That there are brines in the recurrent slope lineae means it is at places as the oases in or own Antarctic desert, where there are brine lakes in places.

New orbiter results point to vast supplies of water that were buried in sediments as the young planet formed an ocean, and were responsible for the later flash floods seen as the planet dried. Those could be oases for subsurface life.
Torbjorn_Larsson_OM
5 / 5 (5) Oct 02, 2015
@antigoracle: " wasn't the plan to look for life?"

You are welcome to read the published Curiosity plans on NASs web site. Nowhere will you find an experiment that looks for life, at least as I remember it.

The plan was, and remains, to look for extinct or extant habitability. First in the form of extinct water environments (check), then in the form of organics (check).

NASA didn't expect to discover extant surface water, but first Curiosity did (DAN reveals a water cycle with condensation at the surface), now MRO did. In both cases the brines would be too cold for life I think (certainly the case for the water cycle condensations) but in the case of the RSL the flows can take spores down to more lenient conditions.
Torbjorn_Larsson_OM
4.3 / 5 (6) Oct 02, 2015
@Physbiz: "what's the issue here?"

Besides the inertia of the political planetary protection protocol, it is a practical matter of experiments. Some experiments will not be able to distinguish between indigenous or transported life or fossils (or trace contaminants). Keeping the experiments clean would avoid false positives and speed up publication of asserted true positives in the early years.

@the lizard: "Wouldn't Earth microbes die when exposed to the radiation that hits Mars?"

Seems lichens survive. [ http://www.lpi.us...5663.pdf ]

Also, the conditions is different just a few mm into rocks where Earth life has evolved to use mineral grains as UV shields while continuing feeding the local ecology from scattered and/or transmitted visible light. (This is how life can survive close to the surface or at edges of rocks in deserts such as Atacama or Antarctica.) [ http://www.scienc...10004306 ]
bschott
1.2 / 5 (5) Oct 02, 2015
@wduckss: "Mars is a large desert area".

That Mars wasn't (had an ocean) and isn't the desert area that Viking seemed to imply is the advancement of 4 decades of hard work. That there are brines in the recurrent slope lineae means it is at places as the oases in or own Antarctic desert, where there are brine lakes in places.

New orbiter results point to vast supplies of water that were buried in sediments as the young planet formed an ocean, and were responsible for the later flash floods seen as the planet dried. Those could be oases for subsurface life.


It's still a large desert, this is an observation, not an implication from a previous lander. We don't classify landscapes based on their subterranean composition. There may be a myriad of things going on beneath the surface...the surface is still a desert.
Returners
2.3 / 5 (3) Oct 02, 2015
Nobody cares if we wipe out some life on Mars, even if it does exist.

I say start seeding mars with Earth extremophiles in an attempt to renew an Earth-like atmosphere.
bschott
1.2 / 5 (5) Oct 02, 2015
Seems lichens survive.


They "survived" a simulated environment and needed to be re-introduced to earth conditions to resume life processes. The nutrients and the process by which your lichens absorb them aren't available on mars.

@antigoracle: " wasn't the plan to look for life?"

The plan was, and remains, to look for extinct or extant habitability. First in the form of extinct water environments (check), then in the form of organics (check).


Bad plan if there was no contingency built in to deal with actually finding something, other than staying away from it. Also, the assumption that a mars microbe and an earth microbe could be confused for each other is pretty rediculous. Two of the main things earth life evolved to exist with are our gravity and magnetic field. Anything "alive" on mars will be unique on a cellular level because of this and I think you know that T-bone.

The points these posters are raising are all valid.

The Singularity
1.7 / 5 (6) Oct 02, 2015
What happens if we need to use that area as a water source? They cant keep avoiding it. A few martian microbes are meaningless if its gona cost the earth to find out it they exist. I wish they would stop faffing about. To all intensive purposes it's our planet, we can do with it what we want.
TheGhostofOtto1923
3.7 / 5 (3) Oct 02, 2015
You would think that organisms which evolved on Mars would be much better suited to living there, and make short work of interlopers including us.

Niches which unadapted earth bugs could survive in should already be occupied by organisms which evolved specifically to occupy them, if life exists there at all.

But if Mars life is sufficiently backward and rudimentary perhaps it wouldn't be able to defend itself from the kind of life which evolved in the context of intensive competition.
TheGhostofOtto1923
2.5 / 5 (4) Oct 02, 2015
quit faffing
And I agree. Establishing an independent self-sustaining colony on another planet is essential to our long-term survival.

And the best way to study life on another planet is to live there.
gkam
2 / 5 (4) Oct 02, 2015
"I say start seeding mars with Earth extremophiles in an attempt to renew an Earth-like atmosphere."
----------------------------------

We will do that inadvertently soon enough. Let us try to find out what is there first, and see if that life is our origin.
Lex Talonis
2 / 5 (4) Oct 02, 2015
This article is bullshit - the original Viking team, equipped the machine with instruments to detect life - and it did.

Gilbert Levin, Arizona State University and former team leader of the Viking Mars Landing mission, presents the argument that their 1976 experiment with the Viking lander discovered life on Mars.
This speech was delivered at the 2013 Humans to Mars Summit, May 7 at George Washington University.

https://www.youtu...y7v30FOg

http://www.nature...-1.15249

Every mission to Marrs since then, has not been sterilised.

And bacteria that can survive the sterilisation process, along with UV-C, Vacuum, and long times in space, has been found growing in the sterilising chamber.....

Duh.
gkam
1 / 5 (3) Oct 02, 2015
Lex, if detected and analyzed with sophisticated equipment, we may be able to differentiate between the DNA of the differing sources of microbial life, or even more basic and easier to see differences.
Lex Talonis
1 / 5 (2) Oct 04, 2015
Good point.....

My main gripe with all this finding life on Marrs BS, is that it's been done, and all the "Me Too's" are running around saying, "One day we might discover it". as if it's never happened.
Physbiz
5 / 5 (1) Oct 04, 2015
@Torbjorn_Larsson_OM
"Besides the inertia of the political planetary protection protocol, it is a practical matter of experiments. Some experiments will not be able to distinguish between indigenous or transported life or fossils (or trace contaminants). Keeping the experiments clean would avoid false positives and speed up publication of asserted true positives in the early years."

Yes, thanks for explaining my point in such detail. Boots on the ground.

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