Exploratour - Life in the Solar System

In the past, Mars was much different than it is today. Liquid water used to flow on the surface, as shown in this picture. Both the Earth and Mars should have been frozen in their early history because the sun was weak at first, but both planets show that water was flowing, which suggests that they both must have had lots of air in place to keep the surface warm. (This effect is called the "greenhouse effect"). In this environment life may have once thrived.

The atmospheres on both planets came out of volcanoes. There were not many volcanoes on Mars, and those volcanoes were never very active. This level of activity is very different from that of the Earth, where volcanism continues today.

The volcanic eruptions probably produced a lot of water. The water eventually fell to the ground or into the oceans. Mars is small, and so cooled off very rapidly. Scientists estimate that the water of Mars was absorbed into the ground and frozen like tundra in the Canadian northwest. Read about NASA's attempts to understand the environment of Mars by leaving this tour and linking to the Exporatour: NASA's Exploration for Life at the bottom of this page. Read more about the comparative evolution of Mars and Earth by linking to the Exploratour on the Evolution of the Solar System.

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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