Dayside and night-side profiles of the Martian ionosphere
Date: 14 November 2012
Satellite: Mars Express
Copyright: ESA/AOES Medialab
Profiles of the electron densities in the Martian ionosphere demonstrate the complexity of the dayside ionosphere (top row, and lower row left and centre) and the marked contrast between the dayside and night-side (lower row, right) measurements.
During the day, extreme ultraviolet light from the Sun ionises the neutral atmosphere resulting in increased electron density. Measurements obtained over the past eight years with the Mars Express Radio Science experiment have produced more than 500 vertical profiles of the ionosphere, some of which show features that had not been predicted by theories of how the ionosphere functions.
Without sunlight to split atmospheric atoms and molecules into ions and electrons, the night-side ionosphere of Mars is very different from the dayside. Electron densities are much smaller and relatively little is known about the vertical structure of the night-side ionosphere.
(A larger version of this image is available from the right-hand menu.)
Last Update: 1 September 2019