PDA

View Full Version : Mars Plume in the News



Ara Pacis
2015-Feb-17, 05:01 AM
Looks like there's a plume or cloud of some sort on Mars at 200 km above the surface. BBC article today. (http://www.bbc.com/news/science-environment-31491805)


The vast plume was initially spotted by amateur astronomers in 2012, and appeared twice before vanishing.

Scientists have now analysed the images and say that say the formation, stretching for more than 1,000km, is larger than any seen before.

Writing in the journal Nature, the researchers believe the plume could be a large cloud or an exceptionally bright aurora.

Not sure if this is has been mentioned here before or not, but search didn't show another thread, even though the images were captured in 2012.

kzb
2015-Feb-17, 06:34 PM
How these plumes can be explained as an aurora when Mars is said to have hardly any magnetic field ?

CJSF
2015-Feb-17, 06:37 PM
There is a relatively strong local crustal magnetic field in the area over which the plume was observed. It is not as strong as Earth's magnetic field, nor is it global in scale. The articles and posts I've read about it expressly say that given the absolute weakness of the magnetic field, they wouldn't expect a very bright aurora, but it cannot be completely discounted.

CJSF

ToSeek
2015-Feb-17, 07:12 PM
Moved to "Astronomy" from "Geology and Planet Surfaces", with a redirect.

borman
2015-Feb-17, 10:43 PM
I wonder if this is related to the methane plumes seen that are too quickly destroyed. Photolysis can be assisted if dust gets entrained in the updraft. If some of these grains have coats of hydrogen peroxide, this can serve to catalyze the destruction. If oxygen can be sourced at this altitude from CO2, some water vapor may form from the products to make clouds. MAVEN should be able to sort out the viable possibilities when it sees one of these.

citpeks
2015-Feb-18, 04:38 AM
Now that attention has been drawn to the plumes by amateur astronomers, additional plumes have been found in old Hubble images.
http://astronomynow.com/2015/02/17/mystery-plumes-in-martian-atmosphere-baffle-scientists/

Is it possible that the plumes could be Martian dust ejected by meteorite impacts?

kzb
2015-Feb-18, 12:57 PM
If it is an aurora, it's far larger and longer-lasting than we get on Earth. Is it likely this could be the result of local magnetism of the crust?

The meteorite theory, if true there should be new impact craters at the sites. I'm not sure about the size of impact required: the dust reaches 250km in altitude. On Earth, the gravity is 3X higher, and the equivalent would be a plume reaching 50 miles altitude. This would be a sizable event to say the least.

Methane plumes: I wonder if it's possible to relate the methane maps back to historic plume sites !?

Personally I wonder if they are giant geysers. Perhaps there are pockets of volcanism still active, and periodically, crustal ice is melted, collapses and is explosively ejected as vapour. If there is a trace of methane clathrate entrained in the ice this would explain the methane in the atmosphere also. Just wondering out loud.

Ross 54
2015-Feb-18, 03:54 PM
A new crater, about 50 meters in diameter, appeared on Mars in March 2012. This is the same time frame as the very high altitude haze or cloud reported there. This was the largest new crater even found on Mars. A connection between the two events seems more than slightly possible.

citpeks
2015-Feb-18, 03:56 PM
The surface of Mars is impacted quite frequently by meteorites that survive the passage through its thin atmosphere. The Mars Reconnaissance Orbiter captured the image of a crater that suddenly appeared in March 2012. ( http://www.space.com/25980-huge-mars-crater-photos.html ) Check out the video in this link. It shows that impacts may even cause landslides.

An impact on the carbon dioxide permafrost could generate a large amount of gas that could propel dust high above the surface.

Ross 54
2015-Feb-18, 06:22 PM
Looked further into the meteorite strike-Martian haze connection. The haze was first seen on March 12th, 2012. The new meteorite crater appeared later, on March 28th. The latter could not have caused the former.

Ara Pacis
2015-Feb-18, 06:28 PM
What about a bolide instead of a surface strike? It would not leave a crater. Is there a low enough angle through which a explosive type of meteor might come in and explode with these results?

citpeks
2015-Feb-18, 06:30 PM
Looked further into the meteorite strike-Martian haze connection. The haze was first seen on March 12th, 2012. The new meteorite crater appeared later, on March 28th. The latter could not have caused the former.

That is true. Even if the time coincided, the location would also have to match.

P.S. It would be interesting if the MRO or another satellite could image the area of the plume to see if there is a new crater there.

borman
2015-Mar-19, 12:52 AM
MAVEN sees high altitude dust cloud
Press releases
Weird aurora and dust cloud found on new Mars mission
http://www.newscientist.com/article/dn27194-weird-aurora-and-dust-cloud-found-on-new-mars-mission.html
NASA Spacecraft Detects Aurora and Mysterious Dust Cloud around Mars
http://www.nasa.gov/press/2015/march/nasa-spacecraft-detects-aurora-and-mysterious-dust-cloud-around-mars/index.html
About the LPW from 46th LPSC
Long Awaited Fundamental Measurement of the Martian Upper Atmosphere from the Langmuir Probe and Waves Instrument on the MAVEN Mission
http://www.hou.usra.edu/meetings/lpsc2015/pdf/2337.pdf

Dust Measurements from the Langmuir Probe and Waves Instrument on the MAVEN Mission
http://www.hou.usra.edu/meetings/lpsc2015/pdf/2356.pdf

DUST OBSERVATIONS USING COMMON MODE MEASUREMENTS FROM THE LANGMUIR PROBE
AND WAVES INSTRUMENT ON THE MAVEN MISSION
http://www.hou.usra.edu/meetings/lpsc2015/pdf/2431.pdf

publiusr
2015-Mar-28, 07:30 PM
I wonder if Mars can lose atmosphere in puffs.

Here on Earth, all of our atmosphere lies pretty well within our magnetosphere.

But with weaker, sporadic fields on Mars, there can be an "inside" and an "outside" within the atmosphere. So could we be seeing an atmospheric prominence of some kind--this being an MHD effect?

So instead of Mars losing atmo gradually, you get puffs.