Astrobiology: A Cautionary Tale

The desire to find life beyond Earth is as great as it has ever been. While the systematic study of Mars and its potential for harboring life – past and present – continues to be explored, new ambitious missions to other targets of interest to astrobiology like Europa and Enceladus are being planned. And with the latest advances in technology and observing techniques, it is now becoming possible to characterize the environments of distant extrasolar planets which are being discovered at an ever-faster pace. But one has to be careful of claims made by some that we will be able to detect proof of life on these distant worlds using new instruments. Science has been down this path once before thinking multiple lines of evidence indicated that extraterrestrial life had been found on an unreachable world only to be disappointed when new observations no longer supported that view.

In my latest essay for Centauri Dreams titled “Astrobiology: A Cautionary Tale”, I review the story of Sinton bands. Named after American astronomer William Sinton who discovered them in 1956, these absorption bands in the infrared spectrum of Mars at the time were taken as yet another piece of evidence to support the widely held view that Mars possessed simple lichen-like plant life. Unfortunately, this old view for life on Mars began to unravel a half a century ago on the eve of the arrival of the first successful mission to Mars, Mariner 4. The one thing we should have learned over the last half of a century is that detecting life on another planet is much more difficult than we had originally imagined.


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Related Reading

“Astrobiology: A Cautionary Tale”, Centauri Dreams, February 27, 2015 [Post]

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