While NASA's Mars rover Curiosity looks for life-friendly ancient environments on the planet's surface, a new probe is being prepared for launch to figure out why Mars lost its protective atmosphere.
Scientists believe that Mars, the fourth planet from the sun, started off much more like Earth, with warm temperatures and water flowing across its surface. But something happened that turned Mars into a cold and dry desert.
PHOTOS: Alien Robots That Left Their Mark on Mars
The Mars Atmosphere and Volatile Evolution mission, nicknamed MAVEN, is designed to provide some answers. From its orbital perch around Mars, MAVEN will track how the solar wind picks away at the planet's thin atmosphere. The information will then be used to create computer models that move backward in time so scientists can determine when the planet was most suited for life and how long that period lasted.
"One of the primary reasons we think the atmosphere was lost is Mars' magnetic field went away and made the atmosphere vulnerable to being stripped away by the sun," said Ashwin Vasavada, deputy project scientist for the Curiosity rover mission at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
With Curiosity, "we're painting the story from the ground up of how that may have happened. MAVEN will begin studying the atmosphere from the top down, watching in real-time as the sun continues to erode away the atmosphere. Together, the two missions will help us understand early Mars," Vasavada said.
NEWS: NASA Plans 'Curiosity Twin' Rover Mission in 2020
MAVEN arrived at the Kennedy Space Center in Florida last week to begin preparations for launch November. It is due to arrive in Mars orbit in September 2014.
"I think it's very, very important that this mission takes place," Jorge Vago, project scientist for the upcoming European Space Agency ExoMars life-detection mission, told Discovery News.
"It's going to have great impact on our understanding, probably not only of Mars, but also of Venus and Earth," Vago said.
NEWS: Europe Probe's Sole Mission: Find Mars Life
European Space Agency scientists are planning to use the Mars Express orbiter for collaborative studies with MAVEN, he added.
In 2016, Europe, in partnership with Russia, plans to send another orbiter to analyze gases still in the planet's thin atmosphere, along with a pathfinder experimental lander. ExoMars, an ambitious mission to search for life beneath the surface of Mars, would follow in 2018.
"Mars is an extremely different planet today than it was in the past," Vasavada said. "That's one of the reasons we go there so often."