The United States has landed seven spacecraft on Mars successfully and returned huge volumes of information — but generally only of daylight subjects. The twin Viking landers could operate through the night, on their plutonium-powered RTGs, but their cameras were not suited for astrophotography. The twin Mars Exploration Rovers did have cameras that could just about photograph Earth as an evening star, but as they were solar-powered, they couldn’t photograph much past sunset before they’d have to start conserving power to get through the night. But the latest visitor to the Martian surface, Mars Science Laboratory “Curiosity”, is both RTG-powered and equipped with cameras that can do a little night work. They’re still not ideal; Curiosity is designed for daylight work and that means its cameras are optimized for that. But it can see stars at night, and lately, it’s been looking at the night sky to search for clouds that form in the dark of night. And it just so happened that there was something interesting to point the camera at during the exercise. Using the MastCam, Curiosity made the first photographs of asteroids from the surface of another planet: Ceres and Vesta, which come so much closer to Mars that they are actually naked-eye visible there.
Inset into the picture are snapshots of other targets photographed during the night. Since this is MastCam, they’re roughly as they’d look from the Martian surface to the naked eye. (Roughly. The Ceres/Vesta images are enhanced, because the human eye is actually much better at seeing stars than this sort of a camera is.)
Pretty cool. 😉