Detecting biomarkers on faraway planets

[Waspie_Dwarf]

Detecting biomarkers on faraway planets

On Earth, life leaves tell-tale signals in the atmosphere. Photosynthesis is ultimately responsible for the high oxygen levels and the thick ozone layer. Microbes emit methane and nitrous oxide into the atmosphere, and seaweeds emit chloromethane gas. These chemicals, when present in sufficient quantities, are indicators of life and are known as atmospheric biomarkers. Detecting them in the atmosphere of an exoplanet should, in theory, be a means of discovering whether life exists on any alien worlds.

While biomarkers have never been spotted in observations of an exoplanet, because their signal is so faint, the new generation of telescopes being planned today, such as the European Extremely Large Telescope, may be sensitive enough to detect them. New research presented to the European Planetary Science Congress at UCL by Lee Grenfell (DLR) aims to explore how such biomarkers might be detected in future.

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[Q-C]

I'm glad to read this. It just seems inevitable, the ultimate in exploration, that humans would explore space in this manner, to me, anyway.

[bison]

The article mentions the detection of ozone (O3) in the atmospheres of exo-planets. If this proves to be possible, such sensitivity supports the idea that it may also become possible to detect technologically produced trace gases. In Earth's lower atmosphere ozone exists at the level of only about 4 parts per million.

Nitrogen oxides (NOx) might be good candidates for technically produced gases that might be detected.

Edited September 14, 2013 by bison