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
Phobos 2 to approach within of Phobos' surface and release two landers, one a mobile , the other a stationary platform, contact with "Phobos 2" was lost. The mission ended when the spacecraft signal failed to be successfully reacquired on 27 March 1989. The cause of the failure was determined to be a malfunction of the on-board computer. The "Phobos 2" infrared spectrometer (ISM) obtained 45000 spectra in the near infrared (from ) in the equatorial areas of Mars, with a spatial resolution ranging from , and 400 spectra of Phobos at 700 m resolution. These observations made it possible to retrieve