Deimos (/ ˈ d aɪ m ə s /; systematic designation: Mars II) [11] is the smaller and outer of the two natural satellites of Mars, the other being Phobos. Deimos has a mean radius of 6.2 km (3.9 …

2024年11月3日 · Deimos is the smaller of the two Martian moons and is less irregular in shape. The largest crater on Deimos is approximately 1.4 miles (2.3 km) in diameter, 1/5 the size of …

7 小时之前 · Today, the moons orbit Mars at average distances that range from some 23,463 km for Deimos to only 9376 km for Phobos. Even so, the authors are still puzzled over whether …

2025年3月13日 · Europe's Hera mission, on its way to the Didymos–Dimorphos double asteroid system, has performed a close flyby of Mars, receiving a crucial gravitational slingshot, testing …

2025年3月14日 · The Hera spacecraft caught the moon Deimos crossing Mars on March 12, 2025. The spacecraft used a flyby of Mars to boost it to its final destination, the asteroid …

2025年1月15日 · Deimos is Mars' outer moon. It's a tiny, irregularly shaped moon and smaller than Mars' other moon, Phobos. Despite being unspectacular, Deimos remains a fascinating …

2025年3月17日 · Deimos, the outer and smaller of the two known moons of Mars, photographed by the Viking 2 orbiter in October 1977 from a distance of about 1,400 km (870 miles). …

2025年3月13日 · Deimos appears to cross Mars. Moving at 9 km/s relative to Mars, Hera was able to image Deimos from as close as 1000 km away, surveying the less-seen opposite side …

2025年3月5日 · Deimos is 9 by 7 by 6.8 miles (15 by 12 by 11 km) and circles Mars every 30 hours. Its surface has a thick layer of dust, as much as 328 feet (100 meters) deep.

Phobos orbits closer to Mars, with a semi-major axis of 9,377 km (5,827 mi) and an orbital period of 7.66 hours; while Deimos orbits farther with a semi-major axis of 23,460 km (14,580 mi) and …