AFP

WASHINGTON-What happened to the water on Mars? How did the Red Planet’s atmosphere become so thin over time? NASA’s MAVEN probe is scheduled to launch Monday on a mission to find out. The unmanned spacecraft aims to orbit Mars from a high altitude, studying its atmosphere for clues on how the Sun may have influenced gas to escape from the possibly life-bearing planet billions of years ago.

The probe is different from past NASA missions because it focuses not on the dry surface but on the mysteries of the never before studied upper atmosphere. “There’s a puzzle piece, I’ll say, that’s been missing with what’s happening in that upper atmosphere,” said David Mitchell, project manager of the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. “That is really what we are going after.”

NASA’s Goddard Space Flight Center in Maryland posted on its website an artist’s video rendition of what Mars might have looked like in a long-gone era when its atmosphere was thick enough to support surface water.