NASA has announced it will in 2013 send a robotic mission to Mars to sniff the Red Planet's atmosphere and gain insights into how most of it was lost.
The $485m Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft - judged as boasting the "best science value and lowest implementation risk" of 20 mission proposals - will "make definitive scientific measurements of present-day atmospheric loss that will offer clues about the planet's history".
Mars once had a much denser atmosphere which allowed liquid water to swill across its surface, but much of the former went awol "as part of a dramatic climate change". Doug McCuistion, director of the Mars Exploration Program, said: "The loss of Mars' atmosphere has been an ongoing mystery. MAVEN will help us solve it."
After arriving at Mars in the fall of 2014, MAVEN will use its propulsion system to enter an elliptical orbit ranging 90 to 3,870 miles above the planet. The spacecraft's eight science instruments will take measurements during a full Earth year, which is roughly equivalent to half of a Martian year. MAVEN also will dip to an altitude 80 miles above the planet to sample Mars' entire upper atmosphere. During and after its primary science mission, the spacecraft may be used to provide communications relay support for robotic missions on the Martian surface.
The MAVEN team will next autumn begin "mission design and implementation" based on designs from NASA's 2001 Mars Odyssey and 2005 Mars Reconnaissance Orbiter. The former is currently mainly involved in examining the Red Planet's surface for water and shallow buried ice, while the latter has returned some impressive photos of the surface in its search for possible future landing sites.
The Reconnaissance Orbiter also acts as a comms relay for other Mars missions, including Phoenix.
Since landing in the Martian arctic back in May, Phoenix has been grubbing about for subsurface water ice, evaluating the chemical composition of the planet's soil and keeping a close eye on the weather. It last week spotted dust devils "dancing" across the extraterrestrial plains, as this animated snap shows. ®