Mars Orbiter Laser Altimeter in the context of LiDAR

Lidar (/ˈlaɪdɑːr/, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranges by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. Lidar may operate in a fixed direction (e.g., vertical) or it may scan directions, in a special combination of 3D scanning and laser scanning.

Lidar has terrestrial, airborne, and mobile uses. It is commonly used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, atmospheric physics, laser guidance, airborne laser swathe mapping (ALSM), and laser altimetry. It is used to make digital 3-D representations of areas on the Earth's surface and ocean bottom of the intertidal and near coastal zone by varying the wavelength of light. It has also been increasingly used in control and navigation for autonomous cars and for the helicopter Ingenuity on its record-setting flights over the terrain of Mars. Lidar has since been used extensively for atmospheric research and meteorology. Lidar instruments fitted to aircraft and satellites carry out surveying and mapping – a recent example being the U.S. Geological Survey Experimental Advanced Airborne Research Lidar. NASA has identified lidar as a key technology for enabling autonomous precision safe landing of future robotic and crewed lunar-landing vehicles.

Olympus Mons (/əˌlɪmpəs ˈmɒnz, oʊ-/; Latin for 'Mount Olympus') is a large shield volcano on Mars. It is over 21.9 km (13.6 mi; 72,000 ft) high as measured by the Mars Orbiter Laser Altimeter (MOLA), about 2.5 times the elevation of Mount Everest above sea level. It is Mars's tallest volcano, its tallest planetary mountain, and is approximately tied with Rheasilvia on Vesta as the tallest mountain currently discovered in the Solar System. It is associated with the volcanic region of Tharsis Montes. It last erupted 25 million years ago.

Olympus Mons is the youngest of the large volcanoes on Mars, having formed during the Martian Hesperian Period with eruptions continuing well into the Amazonian Period. It has been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"), and its mountainous nature was suspected well before space probes confirmed it as a mountain.