The MAVEN spacecraft using the Imaging Ultraviolet Spectrograph observed a bright ultraviolet auroral glow around Mars’ northern hemisphere for five days in December 2014.
“What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”
The aurora here on Earth, like the stunning display of 18 March (and one I missed due to sky conditions) is caused by energetic particles hitting the upper atmosphere and causing gasses to glow. The Martian aurora is also thought to be the Sun, however since Mars has lost it’s protective magnetic field the particles can directly hit the atmosphere.
MAVEN’s Solar Energetic Particle instrument detected a surge in energetic electrons at the onset of the aurora.
It will be very interesting to see if this is repeated following the recent display here and it may not be depending on whether or not Mars is in the path of the solar ejecta.
In the mean time keep an eye on the sky as the Sun is starting to pick up in activity or so it would seem.
For the latest summary of current solar conditions you can check out the WWV text alerts, paying attention to the K index and the lines at the end as in following sample from 18 March:
:Product: Geophysical Alert Message wwv.txt
:Issued: 2015 Mar 18 2105 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Geophysical Alert Message
Solar-terrestrial indices for 18 March follow.
Solar flux 115 and estimated planetary A-index 45.
The estimated planetary K-index at 2100 UTC on 18 March was 5.
Space weather for the past 24 hours has been severe.
Geomagnetic storms reaching the G4 level occurred.
Radio blackouts reaching the R1 level occurred.
Space weather for the next 24 hours is predicted to be minor.
Geomagnetic storms reaching the G1 level are expected.
If you are a ham radio operator or have a shortwave radio you can also hear these messages on WWV at 10 and 15 MHZ. WWV (and sister stations) can be heard on other frequencies, these two frequencies are probably the best all around choices.