NASA’s Perseverance rover has given us an otherworldly skywatching treat — the minuscule Mars moon Deimos, twinkling in the dusty Red Planet skies.
“Skywatching is fun no matter where you are. I took this short time-lapse movie to watch for clouds and caught something else: look closely and you’ll see Deimos, one of two moons of Mars,” Perseverance team members wrote via the mission’s official Twitter account Friday (Aug. 20).
Perseverance, which landed in February inside the 45-kilometer-wide Jezero Crater, usually keeps its head down, studying the Red Planet’s rocks and dirt. After all, the rover’s primary tasks include searching for signs of ancient Martian life and collecting dozens of samples for eventual return to Earth.
The rover does, however, raise its head from time to time, and not just to observe the clouds. Perseverance, for example, assisted in documenting the first few flights of its traveling companion, NASA’s 4-pound (1.8 kilogram) Ingenuity helicopter. Ingenuity is still going strong — the pioneering little chopper recently aced its 12th Martian sortie — but Perseverance began focusing on its own science work a few months ago.
The 7.7-mile-wide (12.4 kilometers) Deimos orbits 14,576 miles (23,458 km) above Mars, completing one nearly circular lap around the planet every 30 hours. Mars’ other moon, Phobos, is about 14 miles (22 km) in diameter and orbits at an altitude of just 5,738 miles (9,234 km). Most astronomers think both satellites are asteroids that were captured by Mars’ gravity.
Earth’s moon, for example, is 2,159 miles (3,475 kilometers) wide and lies at a distance of 238,900 miles (384,470 kilometers) from our planet on average. According to experts, our moon formed from material blasted into space by a massive collision between the proto-Earth and a Mars-sized planet called Theia more than 4.4 billion years ago.
The two small moons of Mars had previously been seen by NASA rovers. Since landing on the floor of Gale Crater in August 2012, Curiosity has obtained many images of Phobos and Deimos. Curiosity’s observations include incredible time-lapse movies of each moon passing in front of the sun, generating partial solar eclipses.
NASA’s Curiosity rover on Mars spotted the moon Phobos passing in front of the sun on March 26, 2019. (Image credit: NASA/JPL-Caltech/MSSS)