Planets and Moons  ID: 20252

Phobos Electric Charging

Mars has two moons, Phobos and Deimos. Both are small, airless bodies with irregular shapes. Because they lack protective atmospheres and magnetospheres, Phobos and Deimos are directly exposed to the solar wind for part of their orbits. The solar wind is a stream of electrically charged particles constantly blowing off the surface of the sun at about a million miles per hour; as it collides with the moons, it is thought to create complex electrical environments.

Now, a simulation by William Farrell of NASA's Goddard Space Flight Center has revealed the details of Phobos's interaction with the solar wind. The simulation predicts that static electric charging occurs on the night side of Phobos and within its shadowed craters. Phobos is frequently cited as a target for future exploration, but according to the study, any robots or humans roving around the night side could build up static electric charge that might affect sensitive equipment. Mission planners will have to face this challenge as they set their sights on the moons of Mars.

Learn more about the finding from NASA or read the science paper by Farrell et al.


For More Information

Advances in Space Research

Animation Credits

Michael Lentz (USRA): Lead Animator
Krystofer Kim (USRA): Animator
Dan Gallagher (USRA): Producer
William Farrell (NASA/GSFC): Scientist
William Steigerwald (NASA/GSFC): Science Writer
Michael Lentz (USRA): Artistic Director
Dan Gallagher (USRA): Narrator
Ernie Wright (USRA): Project Support
Aaron E. Lepsch (ADNET Systems, Inc.): Technical Support
Please give credit for this item to:
NASA's Goddard Space Flight Center Conceptual Image Lab