Using tools developed at the campus’s Space Sciences Laboratory, or SSL, a team of scientists has discovered how Mars has been stripped of its atmosphere over billions of years.
The tools involved, aboard a NASA-directed spacecraft orbiting Mars, were used to collect and analyze particles found both in solar winds and in the Martian atmosphere. The results of the Mars Atmosphere and Volatile Evolution, or MAVEN, mission — announced Thursday — confirmed scientists’ hypotheses that the erosion of the Martian atmosphere was caused, in part, by solar winds.
“The main goal is to count these particles to determine how much is flowing away from Mars at any time,” said Jared Espley, co-investigator for the magnetometer instrument.
Espley explained that Earth is protected from solar winds by its magnetic field. Mars doesn’t have a magnetic field, so the solar wind interacts directly with the atmosphere, magnetizing certain particles. These particles then follow magnetic field trajectories as they are “blown” off the planet by solar winds. Espley compares the deterioration to “how a river is able to erode the canyon through which it flows.”
“MAVEN has detected a plume of material coming from the ionosphere — like a fountain,” said particles and field package lead David Mitchell. “This had been hypothesized. Now it is confirmed.”
Scientists hope that the discovery of how solar winds erode the Martian atmosphere will help understand how it changed from a warm and wet climate billions of years ago, which might have supported life, to the cold and arid planet today.
Mitchell, also the lead for the solar wind electron analyzer instrument and a researcher at the SSL, said that another goal of the MAVEN project is to gather enough data to work backward to understand Martian atmospheric loss throughout the planet’s history.
“There’s been a number of scientists who are developing models which have a number of parameters that would be able to project back in time,” said Jim McFadden, lead for the suprathermal and thermal ion composition instrument. “They need to know the relative role that different processes play in loss mechanisms. MAVEN measures those processes directly.”
Researchers noted that the study of solar storms may give insight into how the sun affected Mars in the beginning of its life as a planet, when the sun was more active. Because the sun is much more energetic during these storms, it more closely resembles solar activity billions of years ago.
“You want to know how the flow of the river day by day erodes the canyon versus the erosion caused by a flood,” Espley said. “That’s the difference between studying solar winds and solar storms.”
Contact Anderson Lanham at [email protected].