How Habitable Was Mars?

Source: LBNL TABL

Commenting on an article in BBC News Science and Environment this past week (April 15, 2014), ESD’s and UC Berkeley’s Michael Manga suggests that the key to life on ancient Mars would be the existence of liquid water.  

To read more, go to:

http://today.lbl.gov/2014/04/21/early-air-points-to-cold-dry-mars/

Citation:

Kite, Edwin S., Jean-Pierre Williams, Antoine Lucas, and Oded Aharonson (2014), Low palaeopressure of the Martian atmosphere estimated from the size distribution of ancient craters. Nature Geoscience, DOI:10.1038/ngeo2137.