Perseverance Rover Captures Earth Vanishing Behind Martian Moon Phobos

During the Martian evening of July 2, Perseverance’s Mastcam-Z instrument captured a series of frames in which Earth, a pinpoint of light, traveled across the sky and was hidden behind the crescent silhouette of Phobos. The images, taken on the rover’s 1,907th sol, were combined into a composite that shows Earth moving from the upper left to the lower right as Phobos sweeps in the opposite direction, ultimately covering the planet.

Justin Maki, deputy principal investigator for Mastcam-Z, called the result a unique self-portrait of Earth with a “Phobos photobomb.” Mark Lemmon, a co-investigator, coordinated the observation, noting that Phobos crosses the Martian sky three times daily but aligning with Earth is uncommon. Phobos, about 27 kilometers across, appears roughly one-third the apparent width of our Moon, while Earth, some 314 million kilometers distant, is reduced to a pixel-size dot. The phenomenon, known as an occultation, differs from eclipses and transits and adds to Perseverance’s record of Martian solar eclipses caused by its moons.