The Mars monolith is a rectangular object (possibly a boulder) discovered on the surface of Mars. It is located near the bottom of a cliff, from which it likely fell. The Mars Reconnaissance Orbiter took pictures of it from orbit, roughly 180 miles (300 km) away. It is estimated to measure about 5 meters wide.
- Natalie Wolchover - Mars 'monolith' isn't the work of Martians (2012) - MSNBC
- Alexandra Ludka - NASA Reevaluates Mars Program After Budget Cuts (2012) - ABC News
- "Has the mystery of the Mars 'Monolith' been solved?". Daily Mail. UK. 6 August 2009. Retrieved 2016-09-25.
- Barras, Colin. "There is a huge 'monolith' on Phobos, one of Mars's moons". Retrieved 2018-01-24.