This image illustrates Mars Global Surveyor studying the planet.
Click on image for full size
Image from: NASA/JPL
The Martian Ionosphere
The Martian ionosphere is a layer of gas that is very high up above Mars. It
extends from about 75 miles up to several hundred miles up above the surface. It is
shown by the shaded region circling the planet in this drawing. Temperatures in this region are very hot. This region may have a complicated interaction with the Martian magnetosphere, which is a region of Mars which is next door to the ionosphere.
Measurements by Mars Global Surveyor will help scientists study
Mars' ionosphere and compare it with those of Earth and Venus. The ionosphere of Mars was even used to help brake the spacecraft and place it into a circular orbit.
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