NASA MAVEN mission solves case of missing Martian atmosphere

NASA’s MAVEN spacecraft has discovered that the solar wind is slowly stripping Mars of its already tenuous atmosphere. Image Credit: Corby Waste / JPL / NASA

Scientists with NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission announced on Thursday that they have identified the key factor in the loss of much of the Martian atmosphere, which resulted in the planet’s transition from a warm, wet world to the cold and dry planet that Mars is today.

The MAVEN team has been able to use data gathered by the spacecraft to determine the rate at which gas is being stripped from the Martian atmosphere by the solar wind. The findings indicate that the erosion of the Martian atmosphere increases significantly during solar storms. The scientists published the results of their research in the November 5th issues of the journals Science and Geophysical Research letters.

“Mars appears to have had a thick atmosphere warm enough to support liquid water which is a key ingredient and medium for life as we currently know it,” said John Grunsfeld, astronaut and associate administrator for the NASA Science Mission Directorate in Washington. “Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere. Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in NASA’s journey to Mars.”

The solar wind is a stream of particles, mostly protons and electrons, that flows from the upper atmosphere of the Sun at a speed of approximately one million miles per hour. The magnetic field carried by the solar wind generates an electric field as it flows past Mars. The electric field accelerates electrically charged gas atoms, known as ions, in Mars’ upper atmosphere and shoots them out into space. The solar wind is stripping away gas at a rate of 100 grams, approximately 1/4 pound, per second.

“Like the theft of a few coins from a cash register every day, the loss becomes significant over time,” said Bruce Jakosky, MAVEN principal investigator at the University of Colorado, Boulder. “We’ve seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active.”

Video courtesy of NASA

Tagged: Mars MAVEN NASA The Range

Jim Sharkey

Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.