If There Is No Life on Mars — Blame the Meteorites. Chromatography Investigates

Searching for signs of life on the surface of planet Mars just got a little harder. Research published online suggests that meteorite impacts on the Martian surface could have long ago destroyed any evidence of life.

So what does this mean in the search for little green men? Let’s see how chromatography has been has been used to see whether organics can be found on the red planet — one of the main precursors to identifying life on Mars.

Finding life on Mars

Humans have long thought about finding life on Mars, but it is only in recent decades — since the development of space probes — that we have been able to do anything about it. Now there have been several probes that have landed on Mars and more are planned for the future — and all have the aim of finding little green men.

The search for life aims to find either residues or precursors of life in the form of organic molecules — peptides, amino acids or even organic fragments would all help researchers piece together the story of life. But some researchers think that the search for life on the surface of mars will be unsuccessful, and instead we should be searching under the Martian surface.

This is because Mars, like Earth, has been bombarded by solar and cosmic radiation and these might have destroyed any organic fragments on the surface. Luckily for us, Earth is now protected by our atmosphere and ozone layer that have the effect of filtering out harmful radiation. But Mars was also blitzed by meteorites — and these could have had the effect of pushing organic signs of life underground and why that’s where we should look. But now new research suggests even searching underground may prove fruitless.

Smashed to smithereens?

Researchers based in London and Edinburgh have investigated the effect of meteorites striking the Martian surface with the results — The nature of organic records in impact excavated rocks on Mars — published in Scientific Reports, and the results suggest that finding life might just be a little harder than first thought.

To mimic the impacts of meteorites of around ten meters in diameter on the surface, the team used a piston-cylinder to crush rock samples containing various types of organic matter. To test the effect of the ‘impact’, the team then used gas chromatography with mass spectrometry (GC-MS) to search for organic fragments.

They found that long chain molecules — such as those found in algae or microbial life — were destroyed by the effect of the impact. But organic molecules of the type found in plants — aromatic type molecules— survived the impacts but were altered by chemical reactions. The analysis of plant based materials is discussed in the article, Are you Made of Sugar?

The work shows that the teams hunting life need to be careful which rocks they look behind — or they may miss life on Mars.