February 7, 2009

Is there life on Mars?



January 23, 2009

This week NASA announced it has found evidence of methane gas plumes spewing from Mars.

I know I’ve lost many of you already, but wait … what if I told you the methane may be belching out from tiny micro-organisms. That’s right — life on Mars.

This was the information printed this week by media organizations around the world, but there’s only one tiny problem — it’s not true.

It seems as though some people are cherry-picking information out of the original NASA press release and an article published this week in the journal Science.

Truth is, scientists aren’t really sure what they’ve found.

Yes, simple organisms such as bacteria produce methane. They are found in places as mundane as our digestive system, where they produce some unpleasant-smelling gases as a by-product of digestion.

They are also found in places on Earth that are as foreign as the red planet itself — hot, underwater deep-sea vents unknown to science until just a few decades ago.

But methane is also produced by various other processes, such as the oxidation of iron (rust) and as a by-product of volcanic activity.

I’m not saying there isn’t reason to get excited.

Life or no life, it’s still an amazing discovery. Either geologically or biologically, Mars is alive.

And there exists the potential for life.

The team that found the methane gas has been studying Mars’ atmosphere for years.

Using NASA’s Infrared Telescope Facility in Hawaii, the team observed distinct patterns of light absorption of the various components in Mars’ atmosphere.

NASA scientists have suspected methane gas on Mars but this was the first time they were able to confirm their suspicions.

One reason this discovery has scientists all a twitter is these same processes occur deep within our own planet.

Ancient micro-organisms that produce methane were one of the earliest forms of life here. It’s reasonable to consider that any potential life on Mars may have similar
origins.

Future missions to Mars will be able to determine the exact origin of the gas, since biologically-produced methane has slightly different properties than geologically-produced methane.

Methane has a relatively simple structure — four hydrogen atoms, centered around one carbon atom.

Hydrogen has a few different forms or isotopes. If the methane plumes on Mars are biologically produced, it is likely that the hydrogen will be lighter than it’s more obese cousin, the deuterium isotope.

Methane is a greenhouse gas, which means the build-up of this gas allows more heat from a planet to be reflected back to the surface.

This makes the planet warmer, similar to how scientists believe life started on our own planet.

The presence of methane and the confirmation of ice on Mars from the Phoenix mission last year is cause for excitement.

Last May, scientists around the world were on the edge of their seats, anxiously awaiting confirmation the Phoenix Mars Lander had successfully descended to the surface of Mars after a nine-month journey through space.

Only six of the last 12 missions have successfully made it to the red planet.

The Phoenix mission proved something long suspected by scientists – there was water, albeit frozen, just below the surface of Mars. Although the presence of water is not proof Mars once supported life, as far as we know, life can’t exist without it.

The great David Bowie once asked the musical question, is there life on Mars?

The answer? Possibly, but let’s not get too far ahead of ourselves.

Cassie Williams is The Halifax Commoner’s science columnist.

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