This is an image of Mars.
Click on image for full size
Image from: NASA
The Earliest History of Mars
The terrestrial planets formed about 4 Billion Years ago. As the process which formed them came to an end, the planets may have been left in either of the following two states:
- very warm, with a softer & pliable interior. There is probably abundant water on the surface. Heat from inside Mars probably caused volcanoes, as well as continental drift.
- cold and rocky, needing to be warmed from the inside.
With Mars, the second case is probably more likely.
Nevertheless, during this time, the surface continued to be bombarded by the remainder of planetary material available nearby, which heated the surface (not the interior) of Mars. This heating was accompanied by hydrothermal activity, or circulation of water within the ground. These conditions are very favorable for certain forms of life.
You might also be interested in:
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
On Mars, the water is trapped, frozen, within the ground. Nevertheless, there is evidence for running water on Mars. When the water is melted and released to the surface, it will run from higher ground
...moreThe drawing shows a crossection of the crust, and the unusual altitude variation of the Martian surface. The figure illustrates the depth of frozen ground at various latitudes, called the cryosphere. The
...more
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
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
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 oval-shaped than that
...more
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
This is image of a Martian sunset illustrates just how thin the Martian atmosphere is. The terrestrial "blue sky" comes about because molecules of the atmosphere scatter sunlight. In this image, the Martian
...more
