Earth and the Martian moon Phobos dance together in a series of images recently acquired by NASA’s Perseverance Mars rover. Earth appears as a point of light in the Martian sky, disappearing behind the crescent of Phobos, the larger of Mars’ two moons.
This is the first time humanity has captured from the surface of another planet an observation of Earth disappearing behind an object.
The image sequence was taken by the rover’s Mastcam-Z instrument at about 7 p.m. local solar time (the Martian evening time where the rover is located) on July 2, the 1,907th Martian day, or sol, of the mission. In the composite image, Earth travels from the upper left of the frame toward the lower right while Phobos, moving from lower left to upper right, sweeps across its path. In the third frame of the sequence, the two meet, and our planet winks out behind the little moon’s shadowed edge.
“The composite image makes for a unique Earth self-portrait, taken from the surface of another planet, with a Phobos photobomb,” said Justin Maki, the Mastcam-Z deputy principal investigator and imaging scientist for Perseverance at NASA’s Jet Propulsion Laboratory in Southern California.
From where Perseverance sits on the rim of Mars’ Jezero Crater, the two objects could hardly look more different. Phobos, a lumpy, potato-shaped moon about 17 miles (27 kilometers) across at its widest, orbits so close to Mars (4,850 miles, or 7,800 kilometers, away) that when the images were taken, Phobos appears roughly one-third the width of Earth’s Moon as seen from our planet. Some 195 million miles (314 million kilometers) away at the time, Earth is reduced to a single, pixel-size dot.
