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Posted by: RNeuhaus Feb 19 2006, 05:38 AM

Fri, 17 Feb 2006 - ESA's Mars Express spacecraft has spotted evidence of auroras over the night time side of Mars. These auroras make v-shaped structures of accelerated electrons and ions, similar to what we see here on Earth. Mars doesn't have a planetary magnetic field, so the discovery of auroras came as a surprise; however, it does have magnetic regions - the remnants of an old planetary magnetic field. Since Mars is always lit from our vantage point here on Earth, it required a spacecraft to find the auroras, which are only detectable at night on Mars.



The auroras are close to a Pole. According to the above picture, due to the incidence of light, it seems to be on the South Pole, Planum Australe. That is a surprise since Mars has no strong magnetic fields to catch any wind solar particles. So there is some magnetic region.

More details http://www.universetoday.com/am/publish/mars_express_aurorae.html?1722006

Rodolfo

Posted by: deglr6328 Feb 19 2006, 11:04 AM

Neat. I wonder if the MERs could observe it with very long exposure night pancam shots. What color would they be? http://www.inoa.it/~stefanob/immagini-lab/co2_scarica_alim.jpg

Posted by: helvick Feb 19 2006, 11:25 AM

If these are in any way similar to Earth aurorae then the MER's are way to far from the poles. Phoenix might be close enough though.

Posted by: djellison Feb 19 2006, 01:21 PM

Well - they'd move around I assume, so between filters you would have motion - it wouldnt really work

MSL, perhaps, I dont imagine it'll be going to a polar region

Doug

Posted by: SigurRosFan Feb 19 2006, 04:36 PM

http://www.unmannedspaceflight.com/index.php?showtopic=1833 - More Martian Auroras, Hundreds of auroras detected on Mars

Posted by: helvick Feb 19 2006, 05:46 PM

Well pointed out Sig.

It's interesting to read the full ESA article and then the Berkely one.

Reading the ESA one I got the distinct impression that this was a "discovery" but they are careful to just say that they have found them with their instruments.
http://www.berkeley.edu/news/media/releases/2005/12/12_mars.shtml referenced in your orignal article claims that they "discovered" them but it does point out that even though they were found in MGS data going back 5 years they didn't actually identify them until after they went looking following an ESA report of an auroral flash in June 2005.

Seems like a case where ESA are somewhat under selling themselves although it seems odd that they don't mention the fact that the MGS team found lots of examples too even though they do mention MGS as the source of the original magnetic anomoly detection that prompted the direct investigation.

One other interesting item in the Berkeley report is that the aurorae are clustered around the surface magnetic anomolies so they are not limited to the polar regions. It also mentions that they are probably mostly UV flashes so humans probably could never see them.

Posted by: Bob Shaw Feb 19 2006, 09:23 PM

At last! An explanation for the flashing sky in 'Robinson Crusoe on Mars'!

'This, you call Mars - we call Waywaykatanga!'

Bob Shaw