This is evidenced by the results of a study published in the journal Advances in Space Research. Scientists have modeled conditions on Phobos' surface and found that during solar flares and coronal mass ejections, the moon's shadow side, as well as the bottom of its largest crater, Stickney, can build up large amounts of static electricity.
Phobos does not have a magnetosphere, so the solar wind can directly bombard the tiny moon. Positively charged particles will be absorbed by its illuminated side, while negatively charged electrons will be attracted to the shadow side. In the case of Phobos, this effect is greatly enhanced by its very fast orbital period. The satellite makes one revolution around Mars in just 8 Earth hours.
According to scientists, charges of static electricity on the surface of Phobos are not dangerous for people in spacesuits, but can pose a potential threat to space technology and electronics. Therefore, the designers of future Mars missions need to take this factor into account. In 2024, JAXA plans to send the MMX apparatus to Phobos, which will have to deliver samples of its substance to Earth. There are also projects to create a habitable base on the surface, which would become a staging post for future manned Martian expeditions.