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. Now, a study from NASA’s Goddard Space Flight Center suggests that the solar wind creates a complex electrical environment around Phobos, giving its night side and shadowed craters a static electric charge. This could impact plans for future robotic and human explorers to study the moons of Mars.