NASA's Perseverance rover, currently exploring the Martian surface, recently captured a rare and fascinating image of Earth disappearing behind Phobos, the larger of Mars' two moons. This is the first time Earth has been seen from the surface of another planet as it disappears behind an object in the sky. The images were taken using the rover's Mastcam-Z instrument on July 2, the 1,907th day of the mission, around 7 p.m. local solar time. In the composite image, Earth appears as a tiny point of light, moving from the upper left to the lower right of the frame, while Phobos moves in the opposite direction. In one of the images, Earth vanishes behind the edge of Phobos, creating a striking visual. Justin Maki, the deputy principal investigator for the Mastcam-Z instrument, described the image as a unique "Earth self-portrait" taken from another planet, with Phobos acting like a photobombing moon. The rover's location on the rim of Jezero Crater offers a view where Phobos and Earth appear vastly different. Phobos, a small, irregularly shaped moon about 17 miles wide, orbits Mars at a distance of about 4,850 miles. From this vantage point, Phobos appears roughly one-third the size of Earth's moon as seen from Earth. Meanwhile, Earth, located about 195 million miles away, appears as a single pixel in the images. The event captured by Perseverance is known as an occultation, a term used in astronomy when a larger object blocks the view of a smaller one from the observer's perspective. This differs from an eclipse, where one object moves into the shadow of another. A lunar eclipse occurs when the moon passes through Earth's shadow, while a solar eclipse happens when the moon passes in front of the sun. In this case, the smaller Phobos appears to block the view of Earth, an event that is sometimes called a "Martian solar eclipse" when Phobos or its smaller counterpart, Deimos, passes in front of the sun as seen from Mars. Mark Lemmon, a co-investigator on the Mastcam-Z team, noted that capturing this event required careful planning and a bit of luck. Phobos passes over the Martian sky three times a day, and Earth is visible in the sky for months at a time. However, aligning the two in such a way that Earth disappears directly behind Phobos is a rare occurrence. The images not only offer a unique view of Earth from another world but also provide valuable data for scientists studying the dynamics of Mars' moons and their interactions with the planet.