Why we need to go back to Mars

Some days ago I saw this amazing "TED talk" about sending an airplane to Mars.

About this talk:

"At TEDxNASA, planetary scientist Joel Levine shows some intriguing -- and puzzling -- new discoveries about Mars: craters full of ice, traces of ancient oceans, and compelling hints at the presence, sometime in the past, of life. He makes the case for going back to Mars to find out more."

More info:

TED talks: http://www.ted.com/talks/joel_levine.html

Website of the Project: http://marsairplane.larc.nasa.gov/