April 16, 2016 – Scientists have long suspected the solar wind of stripping the Martian atmosphere into space, a process that may have turned Mars from a blue world early in its history into the red planet that we see today. In 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter arrived at Mars and began studying its upper atmosphere.
Now, MAVEN has returned the first-ever measurements of solar wind erosion at Mars, observing ions in the upper atmosphere as they pick up energy from the electric field of the solar wind and escape to space.
The MAVEN mission is being led by the University of Colorado Boulder. MAVEN data has enabled researchers to determine the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind.
The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun’s atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space.
Data has revealed that the erosion of Mars’ atmosphere increases significantly during solar storms.
There are roughly 30 LASP scientists, graduate students and undergraduates who are on the science team and analyzing the MAVEN science results. CU-Boulder provided two science instruments and leads science operations as well as education and public outreach for the mission. LASP’s Nick Schneider, Frank Eparvier and Robert Ergun all head up instrument teams on NASA’s MAVEN project.
Lockheed Martin of Littleton, Colorado built the spacecraft and is responsible for mission operations. MAVEN launched to space on a United Launch Alliance Atlas V rocket.