ESA’s Mars Express has shed new light on the Red Planet’s rare ultraviolet aurora by combining for the first time remote observations with in situ measurements of electrons hitting the atmosphere. [...]
These light displays are also found on other planets, including those with powerful magnetic fields such as Jupiter and Saturn. But they can even occur on planets with no magnetic field, such as Venus and Mars. In the absence of a global magnetic field, solar particles can directly strike the planet’s atmosphere to generate an aurora. [...]
Now armed with 10 years of observations, scientists have detected ultraviolet auroras on many occasions, and have analysed in detail how and where they are produced in the martian atmosphere.
“With 10 years of data, we’ve gone much further than the initial detection, and we now have a better understanding of the characteristics and occurrences of this interesting phenomenon,” says Jean-Claude Gérard of the University of Liège, Belgium, lead author of the paper published in JGR: Space Physics.
“The ultraviolet auroras turn out to be very rare and transient: they last only a few seconds. Even though Mars Express has passed over each location many times, detections at a given location do not seem to repeat at later times,” adds Lauriane Soret, also of the University of Liège and lead author of the paper published in Icarus. [More at links]