Mars Geology

Mars is much smaller than Earth. Its diameter is 53% the size of Earth, its surface, 28% and its mass, 11%. However, since oceans cover 71% of the Earth's surface and Mars has no oceans, the land area of both worlds is approximately the same.

Mars' surface has characteristics of both the Earth and the Moon. These include impact craters, lava fields, volcanoes, rivers, dry riverbeds and sand dunes. The surface of Mars is believed to be mostly made of basalt.

The soil of Mars contains iron, silica and other minerals. Bright orange-red regions, whose color comes from the iron oxide in the soil, cover three-quarters of the planet's surface. These regions are called deserts. The color of the deserts gives Mars its characteristic reddish hue, which has caused it to become known as "the red planet".

An "albedo spot" is a large area of a planet that differs from adjacent areas in darkness or brightness. Mars has albedo spots in the form of dark spots on its surface. These dark spots can be seen from telescopes on Earth. Syrtis Major is a well-known dark spot.

The northern hemisphere of Mars is very different to the southern hemisphere. The northern hemisphere is characterized by plains, while the southern hemisphere has deep, old, rugged, craters, similar to those of the Moon.

Among the prominent impact craters of the southern hemisphere is the Hellas Planitia impact basin, which is about 6 km deep and about 2000 km in diameter.

The forms of many of the more recent impact craters suggest that the surface was wet or muddy when the impacts occurred.

The Martian magnetic field is very weak, about two thousandths of the Earth, and with a reversed polarity.