Earth As an Extrasolar Planet

sciencehabit writes "Astronomers have a theory that they can detect whether a planet light years away will be habitable by just looking at how its sun is reflected in its atmosphere. To test the idea, they pretended that they were observing Earth from a distant object — in this case, the moon. And sure enough, they picked up critical components for life in Earth's atmosphere: ozone, oxygen, sodium, and nitrogen."

Comments

The Galileo probe already did this

[De_Boswachter]

"A search for life on Earth from the Galileo spacecraft", Nature, 1993 C. Sagan et al., http://www.nature.com/nature/journal/v365/n6448/abs/365715a0.html

Re:The Galileo probe already did this

[interactive_civilian]

For those without access to Nature, a Google Scholar search turns up a freely downloadable PDF of the full article.

PDF Link

I remember reading about this in Sagan's "The Pale Blue Dot", and thought it was such an awesome idea. I'm looking forward to reading the original paper. :)