Using Earthshine reflected back from the Moon to look for Earth's biosignature

[gary]

In a 29th Feb 2012 article in Nature, researchers using the Very Large Telescope in
Chile have used the polarized reflected sunshine from the Earth that has then struck
the dark portion of the Moon's face and then reflected back to Earth again to
look for biosignatures of Earth.

Originally Posted by Nature

By comparing their measurements with models of how various land and sea surfaces would have reflected polarized light, the researchers found that they could use their data to discern changes in Earth’s cloudiness and to determine that part of the planet is covered with oceans. Beyond these clear signs of habitability, the team identified the biosignature of chlorophyll — which showed up strongly in the April observations, when parts of Brazil, Africa and Europe were illuminated as seen from the Moon, but was almost undetectable in the June data, when hardly any landmasses were lit.

Article here - http://www.nature.com/news/seeing-ou...mirror-1.10136