NASA's next Mars probe is set to piece together longstanding mysteries about the atmosphere of the Red Planet.
Earlier robotic probes and rovers sent to Mars were designed to investigate the surface of the planet, but the space agency's Mars Atmosphere and Volatile Evolution spacecraft (MAVEN) is built for a different target: the planet's atmosphere.
"The Martian atmosphere is a critical piece of the puzzle of how Mars works," Jim Garvin, chief scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said. "Certainly Mars was born with a different atmosphere than we think we see today." [NASA's MAVEN Mars Probe: 10 Surprising Facts]
You can watch a video of Garvin discussing MAVEN and other Mars missions on SPACE.com
The MAVEN spacecraft is set to launch atop an Atlas 5 rocket from Cape Canaveral Air Force Station in Florida on Monday (Nov. 18) at 1:28 p.m. EST (1828 GMT). You can watch the launch live on SPACE.com, via NASA TV, beginning at 11 a.m. EST (1400 GMT).
The $671 million MAVEN mission will study Mars' upper atmosphere to help scientists understand how the Red Planet lost its atmosphere over time. Scientists think that ancient Mars had a relatively thick atmosphere, but now it is only about 1 percent as thick as Earth's, scientists have said.
Scientists don't have a lot of information about Mars' atmosphere. "MAVEN is going to fill in a lot of the gaps that we've known we needed to fill in since the 1970s," Garvin said.
Today, Mars is cold and dry, but evidence suggests that the world was once rich with liquid water. Because Mars is smaller than Earth, its atmosphere is more tenuous, Garvin told SPACE.com.
The atmosphere of Mars was probably subject to harsh solar wind and other factors that could have caused Mars' atmosphere to escape, thinning over time. The Martian atmosphere was "space weathered" away, Garvin said.
By using MAVEN's extensive instrumentation, scientists can combine observations made by rovers on the planet's surface to understand how the atmosphere was lost to space as Mars evolved.
"We need to measure the atmosphere of Mars today, how it works, how it's lost to space, how it interacts with the solar wind, how that relates to the chemistry of the rocks on the surface that we're measuring with Curiosity, that we measured with Spirit and Opportunity," Garvin told SPACE.com. "All that is part of this big ensemble of information we need to really understand how Mars works."
MAVEN is the 10th orbiter launched to Mars by NASA. Currently, the space agency's Mars Reconnaissance Orbiter, Mars Odyssey and the European Space Agency's Mars Express are active spacecraft in orbit around Mars. The Mars rover Curiosity and Opportunity are both functioning on the surface of the planet.
"Mars is a big place and really, it's a rather tricky place. It has beguiled us ever since we sent our first spacecraft by the planet, and so, as we start to piece together the information to understand this world, a place where we can reasonably ask, 'Could there have been a record of past life?' We need to bring all the information together to pose that question in an informed way."