This is an image of Mars.
Click on image for full size
Image from: NASA

The Cooling of Mars

Many of the reasons the history of Mars is different from that of the Earth stem from the small size of Mars. Mars is about 1/3 the size of the Earth. This means that it was able to cool much more rapidly over time than did the Earth.

When Mars formed about 4 Billion Years ago, it may have been left relatively colder than the other terrestrial planets. Further cooling inward from the surface of Mars froze the water, preventing the formation of special hydrated-minerals which allow for movement of the lithosphere. Without the ability to subduct and remelt, the Martian lithosphere slowly thickened to the point of being immovable, like hardening candy.

Later there was a period of warming and volcanism, caused by a warm plume of material rising from the deep interior of Mars, which pushed out and raised the crust, and created the Tharsis Bulge, Olympus Mons, and the other volcanoes. This volcanism influenced the subsequent Martian climate.


You might also be interested in:

Martian Volcanoes

On this map of Mars, the lightly cratered Tharsis Ridge is shown, as well as the heavily cratered Martian highlands (near the bottom of the picture), and Valles Marineris to the right. The volcanoes are...more

Olympus Mons

The largest volcano in the solar system is Olympus Mons, shown in the image to the left. Olympus Mons is a Martian shield volcano. The altitude of Olympus Mons is three times the altitude of the largest...more

The Transfer of Water in Martian History

The unusual global geography of Mars helps to explain the fact that water has been drawn from the southern hemisphere to the northern hemisphere of the planet through all of Martian history (that is, from...more

The Martian Cryosphere

The Martian geography is one of high altitudes at high southern latitudes and low altitudes at low latitudes. The ground is less frozen at low latitudes because it is warmer and water can evaporate. Thus,...more

Martian Floods

Separate from the Martian outflow channels, or the river valley networks, are large Martian lakes (600 km, or ~1000 miles across) which exhibit evidence of a periodic and catastrophic release of water...more

Martian Fog

This is an image of fog in a Martian canyon. The presence of fog provides evidence of water, and a water cycle on Mars. More fog has been seen in images returned by Mars Global Surveyor of the south polar...more

Martian Orbital Eccentricity

The Martian climate is more influenced by the shape of the Martian orbit than the climate of the Earth is influenced by the shape of the Earth's orbit. The orbit of Mars is more elliptical than that of...more

Martian Storm

This is an image of a storm moving across the Martian terrain. The camera is looking down upon the storm and the storm front forms a spiral pattern, the same way terrestrial storms are presented on the...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA