The Surface of Mars may be More Uninhabitable than We Thought

Fagjun | Published 2017-07-07 09:14

Mars in UV light
[Photo by Reuters]

Don't plan for that trip to Mars just yet. Lab experiments have found that the surface of Mars is actually inhospitable to life. This also deals a blow to current efforts to find life on our neighboring planet.

Humanity has long been fascinated with the possibility of life on Mars. There have been numerous works of fiction exploring the possibility that we may have very close interplanetary neighbors. There have also been numerous studies on how and where we can find life on Mars. However, we've come up empty-handed. Now, it seems that there's even less of a possibility of finding life on the red planet, at least not on its surface.

Researchers have found that there is a substance on the surface that kills bacterial life forms. Studies have shown that life on Mars may be microscopic, making this discovery quite discouraging. It turns out that the Martian surface is even more inhospitable than we thought.

Toxic Perchlorates and Bacteria

Bacillus subtilis stain
[Image by WMrapids]

Experiments show that compounds, called perchlorates, on Martian soil turn into bacteria killers once exposed to UV light. Unfortunately, UV light basically drenches the planet's surface, leaving no room for non-bactericidal perchlorates. NASA's 2008 Phoenix Lander mission also found that perchlorates are in abundance on Mars. Thus, the surface is not only inhospitable, it's also likely to be sterile.

Perchlorates, the researchers explain, are stable when they're at room temperature. However, high heat activates them. Though the surface of Mars is cold, UV light can activate perchlorates as well. Researchers were able to mimic the conditions on the Martian surface and found that perchlorates can kill bacteria within minutes.

The researchers found that radiation can break perchlorates down to the chemicals chlorite and hypochlorite. It seemed that these two chemicals are what's lethal to the bacteria. The findings also showed that radiation makes iron oxides and hydrogen peroxide, which Martian soil also contains, toxic to bacteria in the presence of perchlorates. In fact, this combination of iron oxides, hydrogen peroxide, and perchlorates kill bacteria 11 times faster than just perchlorates.

It's possible that there was life on the Martian surface sometime in the past. However, it's extremely likely that the surface is now barren and devoid of any forms of life.

Going Past the Surface of Mars

Life may have lived on the Martian surface in the past, but it's impossible now.
[Image by ESO/M. Kornmesser]

However, one thing that we should keep in mind is that the researchers only tested the effects of perchlorates on cultures of one kind of bacteria, Bacillus subtilis. It's possible that other life forms or other kinds of bacteria may be able to survive the perchlorates. Researchers would need to do more tests to see if perchlorates are toxic even to other bacterial life.

This also doesn't mean that there's no life on Mars at all. This may just mean that we'll have to dig below the surface if we're to increase the chances of finding life on Mars. Scientists have already looked into the possibility of searching the Martian subsurface for organisms called methanogens. Thus, though life probably won't thrive on the surface of Mars, it may somehow be thriving below the surface.

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