NASA’s Perseverance rover has successfully documented a rare astronomical event from the surface of Mars, capturing images of Earth as it passed behind Phobos, one of the planet's two moons. This observation marks the first time such an occultation—where a foreground object completely blocks a more distant one—has been recorded from another planet.

The sequence was captured on July 2, 2026, during the 1,907th sol of the mission, using the rover's Mastcam-Z instrument. At approximately 7 p.m. local Martian time, the rover observed Earth appearing as a small point of light as the potato-shaped moon Phobos moved across its path. Justin Maki, deputy principal investigator for Mastcam-Z at NASA’s Jet Propulsion Laboratory, described the resulting composite image as a unique "Earth self-portrait" featuring a "Phobos photobomb."

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While Phobos orbits Mars frequently, catching the moon in direct alignment with Earth requires precise planning. Mark Lemmon, a co-investigator at the Space Science Institute who organized the observation, noted that while both bodies are often visible in the Martian sky, the specific timing needed to capture one behind the other involves both careful calculation and good fortune.

At the time of the event, Earth was approximately 195 million miles (314 million kilometers) away, appearing as a single pixel, while Phobos—measuring about 17 miles (27 kilometers) across—was positioned roughly 4,850 miles (7,800 kilometers) from the rover. Astronomers distinguish this event from eclipses and transits; while an occultation involves a larger-appearing body blocking a smaller one, a transit occurs when a smaller-appearing object crosses the face of a larger one, a phenomenon Perseverance has previously observed when Martian moons cross the Sun.

Source: NASA