Perseverance has caught the silhouette of Phobos, one of the two Martian moons, sweeping across the solar disk in a fresh transit video from Jezero crater.
This image of Phobos in front of the Sun was captured by Perseverance’s Mastcam-Z camera on August 12, 2026. Image credit: NASA / JPL-Caltech / ASU / MSSS / SSI.
Phobos, the larger and innermost of Mars’ two moons, was discovered by the American astronomer Asaph Hall on August 17, 1877.
The moon is approximately 26 x 22 x 18 km (16.2 x 13.7 x 11.2 miles) and has a very lumpy appearance.
It is an unusual satellite, orbiting closer to its planet than any other moon in the Solar System.
Phobos orbits Mars about 6,000 km (3,700 miles) from the surface and completes an orbit in just 7 hours and 39 minutes.
It orbits so close to the Martian surface that the curvature of the planet would obscure its view from an observer standing in Mars’ polar regions.
Its orbital period is about 3 times faster than the rotation period of the Red Planet, with the unusual result among natural satellites that Phobos rises in the west and sets in the east as seen from Mars.
Unlike Earth’s Moon, Phobos is too small and too near its planet to fully block the Sun, so any eclipse it causes from the Martian surface is really a partial transit, with the moon’s dark, potato-shaped outline sliding across the solar disk rather than covering it.
“Perseverance used its Mastcam-Z camera to capture the silhouette of Phobos as it crossed in front of the Sun on August 12, 2026, the 1,948th Martian day, or sol, of the mission,” members of the Perseverance team said in a statement.
“The animation has been tinted to simulate what a human would see if they were watching the transit from the Martian surface through protective solar eclipse glasses.”
This isn’t Perseverance’s first look at the phenomenon: the rover has recorded several Phobos transits since touching down at Jezero crater in February 2021.
“By comparing the various recordings, scientists can refine their understanding of the potato-shaped moon’s orbit, learning how it is changing,” the researchers said.
“Eons from now, Phobos’ orbit is expected to eventually send the moon toward the Red Planet’s surface.”
