Mars Geography

The surface of Mars reveals evidence of great cataclysms that have no equivalent on Earth.

Information obtained from the Mars Reconnaissance Orbiter and Mars Global Surveyor has led scientist to believe the northern hemisphere of Mars contains a huge impact basin, known as the Borealis basin, which is 8500 kilometers in diameter and covers 40% of the surface of the planet - the largest impact basin in the solar system.

The Borealis basin is believed to have been formed 3900 million years when the planet was hit by an object 2000 kilometers in diameter. The impact would have caused giant volcanoes to form along the edge of the basin

The Tharsis volcanic complex, which is near the equator, includes Olympus Mons, the largest volcano in the Solar System. This volcano has a height of 25 km (more than two and a half times the height of Mount Everest). Its base is 600 km wide.

To the East of Tharsis lies Valles Marineris. With a length of 2,700 km, and a width of 500 km and a depth of between 2 and 7 km, Valles Marineris dwarfs the Grand Canyon. It was formed by land sinking when the Tharsis bulge formed.

Hellas Planitia, an enormous impact basin, can be found in the southern hemisphere.

In May 2007, evidence of ancient volcanic activity was discovered at the plateau known as Home Plate, which is inside the Gusev Crater.

Several places on Mars show clear evidence of erosion, whether by wind or by water. There are what could be winding riverbeds. Some suggest that in the remote past, lakes and even a vast ocean in the northern region of the planet.

The Mars Global Surveyor has detected several regions with extensive low-intensity magnetic fields. This implies that there was once a global magnetic field, but it has since disappeared.

Unlike Earth, Mars has no active tectonic plates. There no evidence of recent surface movements, such as the folding of mountains, which have happened frequently in Earth's history.

The study of Mars' geography is known as "aerography."