Mars surface ‘more uninhabitable’ than thought: study – Phys.Org

July 6, 2017 Latest lab tests show salt minerals on Mars kill basic life form bacteria, implying the 'Red Planet' is more uninhabitable than previously thought

Hopes of finding life on Mars, at least on the surface, were dealt a blow Thursday by a study revealing that salt minerals present on the Red Planet kill bacteria.

In lab tests on Earth, the compounds known as perchlorates killed cultures of the bacteria Bacillus subtilis, a basic life form, a research duo from the University of Edinburgh's School of Physics and Astronomy reported.

Perchlorates, stable at room temperature, become active at high heat. Mars is very cold.

In the new study, Jennifer Wadsworth and Charles Cockell showed the compound can also be activated by UV light, without heat, in conditions mimicking those on the martian surface.

It killed bacteria within minutes, said the team, implying the planet was "more uninhabitable than previously thought."

"If we want to find life on Mars, we have to take this into consideration and look at trying to find sub-surface life that wouldn't be exposed to these conditions," Wadsworth told AFP.

Perchlorates are natural and man-made on Earth, but are more abundant on Mars where they were first recorded by NASA's Phoenix Lander in 2008.

The fact that perchlorates killed B. subtilis in the presence of UV radiation did not necessarily mean that all other life forms would similarly die, said Wadsworth. Further tests would have to be done to confirm this.

Perchlorates have previously been spotted in lines, thought to be brine streaks, on the surface of Mars.

Their presence was presented as evidence by scientists in 2015 of liquid water on the Red Planet.

But the new study said brine seeps, "although they represent local regions of water availability, could be deleterious to cells" if they contain perchlorates.

The findings do contain some good news.

They mean that organic contaminants left on Mars by robotic exploration, of which B. subtilis is a common one, are unlikely to survive long.

It is widely accepted that the Red Planet once hosted plentiful water in liquid form, and still has water today, albeit frozen in ice underground.

Liquid water is a prerequisite for life as we know it.

Explore further: Mars rover scientist hopes to find more evidence of liquid water

2017 AFP

IC 342 is a challenging cosmic target. Although it is bright, the galaxy sits near the equator of the Milky Way's galactic disk, where the sky is thick with glowing cosmic gas, bright stars, and dark, obscuring dust.

Astronomers have discovered a rare, warm, massive Jupiter-like planet orbiting a star that is rotating extremely quickly. The discovery raises puzzling questions about planet formation neither the planet's comparatively ...

A project that explores whether there is a musical equivalent to the curvature of spacetime will be presented on Thursday 6July by Gavin Starks at the National Astronomy Meeting at the University of Hull.

Yale researchers have identified 60 potential new "hot Jupiters"highly irradiated worlds that glow like coals on a barbecue grill and are found orbiting only 1% of Sun-like stars.

When it comes to the distant universe, even the keen vision of NASA's Hubble Space Telescope can only go so far. Teasing out finer details requires clever thinking and a little help from a cosmic alignment with a gravitational ...

European and Japanese scientists Thursday proudly unveiled the BepiColombo spacecraft ahead of its seven-year journey to Mercury, to explore one of the Solar System's most enigmatic planets.

Adjust slider to filter visible comments by rank

Display comments: newest first

This can only come as a shock to those who believe we capture all of the variables in our "simulations".

How do perchlorates affect us human life?

I say misinformation. Have these scientist never heard of Tardigrades or lichen ?

Such a finding has no significance for occasional human colonies at Mars. Its water must be distilled of soil anyway and greenhouses for farming will also block UV. The worse problem is, that the colonization of Mars has no practical meaning not to say economical sense.

Perchlorates are what make you a Jedi.

Perchlorates are poison, not that that matters one iota when it comes to colonization. Man will get it done, whether she speaks Engrish or not remains to be determined.

We settled Phoenix, people live there in the summer, Mars has to be easier.

Perchlorates can be used to generate oxygen. This is useful to human life.

The same feat was accomplished in Harlem, Baltimore, Camden, urban Washington, DC; Atlanta, Detroit, Chicago, Pacoima...- though it cost $10 trillion during the Obama administration.

Perchlorates....as in Sodium Perchlorate, sold as "Staffel's Weed Killer". Also worked as a rocket propellant when mixed with other substances. Launched many rockets with it. So...it seems mars is covered with 1) weed killer and 2) an essential ingredient for rocket fuel.

We would be better served trying to colonize Antarctica than Mars. If Earth has 100 apocalyptic events it would still be thousands of times more hospitable than Mars.

As a practical matter, the first explorers will rig for Mars as if it were as dead as the Moon -- zero atmosphere, food and water. Any mitigating factor will just be a bonus. Also, this may be a local phenomenon. It may not apply to the whole planet.

Islamic state on Mars !

My parents used to brew coffee in a perchlorator.

So much for Hollywood's idea of living on Mars like Martian as setting up a colony on Mars may need to be dialed back with something on the Moon first; then lessons learn after spending a few years on the Moon might a manned mission to Mars possible.

You need mircrobes that live in acide mine waste

Really, only lunatics would even give a thought that life could have existed on Mars.

OK, I'm on Mars. 1. Where is my air? 2. Where is my water? 3. Where is my food? 4. What will stop me from going crazy from isolation after 6 months?

The martian surface average is more like 8 Rad/year, which can be further mitigated by choice of landing site. The radiation environment in Hellas planitia for instance is some 4 rad/year, still quite a bit more the the 0.6rad/year we get on Earth, but roughly the same as our astronauts are exposed to on the ISS. This also assumes astronauts are just hanging out on the surface without any protection. At the end of the day, radiation isn't the most serious concern in colonizing Mars.

Really, only lunatics would even give a thought that life could have existed on Mars.

@bscott: "This can only come as a shock to those who believe we capture all of the variables in our "simulations"."

It may come as a shock to those who believes that the purpose of simulations is to capture "all" variables instead of deepening understanding by capture system behavior. Especially if they do not see that this was a necessary experimental study (which can lead up to simulations).

@Al: "Shall we spend a $trillion to personally verify Mars is a crap hole?"

We already know that, but it is the best crap hole after Earth for a lot of things such as robotic exploration of once habitable environments. And I doubt Jennifer and Charles had access to that much money

Besides the non-sequitur, that is an erroneous claim. Not only have we seen it happen - Earth started out sterile, now it is not, so life appeared from sterile conditions - we have corroborating and yes, reproduced, evidence from bioinformatic studies of the geological conditions that resulted in emergence of life. [Weiss MC et al. 2016, The physiology and habitat of the last universal common ancestor. Nature Microbiology.; reproduced in: Williams TA et al. 2017. Integrative modeling of gene and genome evolution roots the archaeal tree of life. PNAS.]

Excitingly that geological system is known to have existed on Mars - Spirit found an example - but also in Enceladus - Cassini found that from its plumes, and can be a generic feature of small (chondrite core) *and* large (heated core) ocean moons that are not ice locked towards the core. (So not every ocean moon, unfortunately.)

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

View original post here:
Mars surface 'more uninhabitable' than thought: study - Phys.Org