Mars 101 is an introduction to what we know and hope to discover about Mars. Like the researchers studying the Red Planet, you can learn about Mars by comparing its similarities and differences to Earth.
Mars is a cold, dry, desert landscape of sand and rocks. Many land features on the present-day surface of Mars, such as volcanoes, canyons, and valleys, make it look very similar to Earth, but humans could not survive in the present environment on Mars. The average surface temperature is -63 degrees C (-81 degrees F), and nighttime temperatures on Mars can plunge to -110 degrees C (-170 degrees F). By comparison, the lowest temperature ever recorded on Earth was -89 degrees C (-130 degrees F) at Vostok, Antarctica in July, 1983.
Surface Features and GeologyMars is only about one-half the diameter of Earth, but both planets have roughly the same amount of dry land surface area. This is because over two-thirds of the Earth's surface is covered by oceans, whereas the present surface of Mars has no liquid water.
This global image of Mars was taken by the Wide-Field Planetary Camera 2 on the Hubble Space Telescope. The north polar cap can be seen at the top, and the immense rift valley called Valles Marineris is visible in the lower left. (Image Credit: Philip James, University of Toledo; Steven Lee, University of Colorado; and NASA)
Mars is a desert landscape of sand and rocks. This false-color image was taken in November 2005 by Rover Spirit's panoramic camera near an outcrop called "Seminole." (Image Credit: NASA/JPL-Caltech/Cornell)
Located on the Big Island of Hawaii, Mauna Loa is the largest volcano on Earth. Mauna Loa's summit caldera has gases and steam rising from fumaroles along a fissure that erupted in July 1975. The caldera is about 3 km (1.8 miles) wide. (Image Credit: R.B. Moore, USGS)
The Martian surface is also covered with many impact craters -- a remnant of the time in the planet's geologic history when it was heavily bombarded by planetary debris. Since an older planetary surface will have more impact craters than a young surface, scientists are able to deduce the age of various regions on the Martian surface by studying the distribution of impact craters.