Global Climate & Habitability: September 2013

During the Archean eon, between about 3.8 billion years ago and 2.5 billion years ago, the Sun was about 20 to 25 percent fainter than it is today. With less sunlight to warm the Earth, the oceans should have been frozen over, but geological evidence suggests that this was not the case.

Earth's Habitable Lifetime

Findings published today in the journal Astrobiology reveal the habitable lifetime of planet Earth - based on our distance from the sun and temperatures at which it is possible for the planet to have liquid water.

In today's mailing, Hogg et al. propose image modeling techniques to maintain 10-ppm-level precision photometry in Kepler data with only two working reaction wheels.

Observations of the Earth as a planet using the earthshine technique (i.e. looking at the light reflected from the darkside of the Moon), have been used for climate and astrobiology studies.