Solar eclipses on Mars a Martian day is 24 hours 37 minutes long, meaning that Phobos can create two eclipses per Martian day. These are annular eclipses, because Phobos is not quite large enough or close enough to Mars to create a total solar eclipse. Deimos is too small (about ) and too far from Mars to cause an eclipse. The best an observer on Mars would see is a small spot crossing the Sun's disc. Both moons are too small to cast a shadow on Mars that can be seen from Earth. However, shortly after the first artificial satellites were placed in orbit
Moons of Mars pre-1925 astronomical convention that began the day at noon, give the time of discovery as 11 August 14:40 and 17 August 16:06 Washington mean time respectively). At the time, he was deliberately searching for Martian moons. Hall had previously seen what appeared to be a Martian moon on 10 August, but due to bad weather, he could not definitively identify them until later. Hall recorded his discovery of Phobos in his notebook as follows: The telescope used for the discovery was the 26-inch (66 cm) refractor (telescope with a lens) then located at Foggy Bottom. In 1893 the lens was