APOD: 2024 September 7 - Small Moon Deimos

Good morning, Rallypoint, and welcome to the September 7th edition of Astronomy Picture of the Day (APOD). NASA's Mars Reconnaissance Orbiter (MRO) began its mission in March 2006 when it initially entered its first orbit of the Red Planet. Its purpose is to observe the climate of Mars, investigate geologic forces, and to provide reconnaissance of future landing sites, and relaying data from surface missions back to Earth. To support these objectives, the MRO carries different scientific instruments, including three cameras, two spectrometers and a subsurface radar. One of the cameras snapped these two image of the smaller Martian moon Deimos.

Johannes Kepler first wrote about the possibility of Martian moons in 1610. But the actual discovery of Deimos and its larger sibling (Phobos) had to wait until 1877. Deimos was discovered by Asaph Hall at the United States Naval Observatory in Washington, D.C. Hall, who also discovered Phobos shortly afterwards, had been specifically searching for Martian moons at the time.