Jupiter's moon Ganymede is seen in transit over the great red spot. It does look like it is staring at us.
Jupiter's largest moons don't go completely dark when the giant planet blocks their sunlight, astronomers have found.
The discovery could reveal more about Jupiter's mysterious upper atmosphere, which the researchers suspect is responsible for keeping the moons lit when they are not directly illuminated by the sun. This research could also help scientists better understand the atmospheres of alien planets, study team members said.