APOD: Global Aurora at Mars (2017 Oct 06)

APOD Robot · Post by **APOD Robot** » Fri Oct 06, 2017 4:10 am

Global Aurora at Mars

Explanation: A strong solar event last month triggered intense global aurora at Mars. Before (left) and during (right) the solar storm, these projections show the sudden increase in ultraviolet emission from martian aurora, more than 25 times brighter than auroral emission previously detected by the orbiting MAVEN spacecraft. With a sunlit crescent toward the right, data from MAVEN's ultraviolet imaging spectrograph is projected in purple hues on the night side of Mars globes simulated to match the observation dates and times. On Mars, solar storms can result in planet-wide aurora because, unlike Earth, the Red Planet isn't protected by a strong global magnetic field that can funnel energetic charged particles toward the poles. For all those on the planet's surface during the solar storm, dangerous radiation levels were double any previously measured by the Curiosity rover. MAVEN is studying whether Mars lost its atmosphere due to its lack of a global magnetic field.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

Boomer12k · Post by **Boomer12k** » Fri Oct 06, 2017 4:34 am

Wonder what it would look like from the surface... um...with ultraviolet imaging of course... would you need sun screen?

I guess without a significant magnetosphere... Mars was doomed...

:---[===] *

HDSchaefer · Post by **HDSchaefer** » Fri Oct 06, 2017 4:50 am

The linked file appears to not be on the server.

Guest · Post by **Guest** » Fri Oct 06, 2017 5:12 am

Is anyone aware of any computational models that attempt to characterize the effect of satellites colliding w/ air molecules? The interaction brings the ISS down about 10 meters per orbit. That energy goes into accelerating some number of air molecules to about 16kps (greater than escape velocity).

The main question is: How much of the atmosphere is lost to interplanetary space due to orbiting satellites?

Ann · Post by **Ann** » Fri Oct 06, 2017 6:24 am

Guest wrote:Is anyone aware of any computational models that attempt to characterize the effect of satellites colliding w/ air molecules? The interaction brings the ISS down about 10 meters per orbit. That energy goes into accelerating some number of air molecules to about 16kps (greater than escape velocity).

The main question is: How much of the atmosphere is lost to interplanetary space due to orbiting satellites?

Mars is likely to have lost atmosphere for 3-4 billion years. The atmospheric loss of Mars caused by Martian probes and satellites during the last few decades is in all likelihood negligible.

Ann

Edited thanks to heehaw.

NoseyNick · Post by **NoseyNick** » Fri Oct 06, 2017 1:00 pm

HDSchaefer wrote:The linked file appears to not be on the server.

"The requested URL /apod/image/1710/pia21855-16c.jpg was not found on this server" here too. I'm used to automatically clicking for the hires version :-O

heehaw · Post by **heehaw** » Fri Oct 06, 2017 1:08 pm

Anne, tiny correction, the word is negligible, not negligent. I would be negligent, were I not to (gently) point this out!

neufer · Post by **neufer** » Fri Oct 06, 2017 1:18 pm

heehaw wrote:
Anne [sic], tiny correction, the word is negligible, not negligent. I would be negligent, were I not to (gently) point this out!

http://www.etymonline.com/index.php?allowed_in_frame=0&search=negligible wrote:
negligible (adj.) "capable of being neglected," 1819, from negligence + -ible.

negligence (n.) mid-14c., from Old French negligence "negligence, sloth; injury, injustice" (12c.), and directly from Latin neclegentia, neglegentia "carelessness, heedlessness, neglect," from neglegentem (nominative neglegens) "heedless, careless, unconcerned," present participle of neglegere "to neglect").

Chris Peterson · Post by **Chris Peterson** » Fri Oct 06, 2017 1:27 pm

APOD Robot wrote:For all those on the planet's surface during the solar storm, dangerous radiation levels were double any previously measured by the Curiosity rover.

Just another reason that people like Musk are absolutely bonkers in thinking we should have a colony there! (Even a small scientific base is silly; but a colony of millions? You'd have to have something wrong with you in the first place to want to live in a hellhole like that.)

bystander · Post by **bystander** » Fri Oct 06, 2017 1:50 pm

HDSchaefer wrote:The linked file appears to not be on the server.

NoseyNick wrote:"The requested URL /apod/image/1710/pia21855-16c.jpg was not found on this server" here too. I'm used to automatically clicking for the hires version :-O

Try pia21855-16.jpg

Ann · Post by **Ann** » Fri Oct 06, 2017 2:05 pm

heehaw wrote:Anne, tiny correction, the word is negligible, not negligent. I would be negligent, were I not to (gently) point this out!

Thanks, you're right!

Ann

Fred the Cat · Post by **Fred the Cat** » Fri Oct 06, 2017 4:30 pm

On Earth we have the aurora borealis and aurora australis. Don’t you think Mars needs its aurora named too

Aurora marsalis

Wow - that sounds good.

Chris Peterson · Post by **Chris Peterson** » Fri Oct 06, 2017 4:38 pm

Fred the Cat wrote:On Earth we have the aurora borealis and aurora australis. Don’t you think Mars needs its aurora named too :?:

Aurora marsalis :idea: Wow - that sounds good. :content:

Since Mars has both a northern and a southern hemisphere, those in the north might reasonably be qualified with "borealis" and those in the south with "australis". Of course, from a physical sense, there's not really a necessity to qualify them since they're whole-planet phenomena there.

Ann · Post by **Ann** » Fri Oct 06, 2017 5:19 pm

Fred the Cat wrote:On Earth we have the aurora borealis and aurora australis. Don’t you think Mars needs its aurora named too?

Aurora marsalis Wow - that sounds good.

I thought you'd direct us to a recipe for chicken with Marsala wine. Eat (and drink) too much, and you may see colorful auroras marsalis all around you...

Ann

Fred the Cat · Post by **Fred the Cat** » Fri Oct 06, 2017 7:58 pm

Ann wrote:
Fred the Cat wrote:On Earth we have the aurora borealis and aurora australis. Don’t you think Mars needs its aurora named too?

Aurora marsalis Wow - that sounds good.
I thought you'd direct us to a recipe for chicken with Marsala wine. Eat (and drink) too much, and you may see colorful auroras marsalis all around you...

Ann

All recipes are subject to modification

just like my spelling..

..and mind-set.

Guest · Post by **Guest** » Fri Oct 06, 2017 8:19 pm

Ann wrote: Mars is likely to have lost atmosphere for 3-4 billion years. The atmospheric loss of Mars caused by Martian probes and satellites during the last few decades is in all likelihood negligible.

Ann

We might characterize the loss as 'negligible' when referring to the impact of a few satellites over a short time period. If we ask the question more generally, and if we think over the longer term, is it safe to say that, in all cases, atmospheric erosion caused by satellites is negligible?

No computational models that aim to quantify the rate of loss of Earth's atmosphere due to satellites known to readers of this forum?

heehaw · Post by **heehaw** » Fri Oct 06, 2017 11:41 pm

Chris Peterson wrote:
APOD Robot wrote:For all those on the planet's surface during the solar storm, dangerous radiation levels were double any previously measured by the Curiosity rover.
Just another reason that people like Musk are absolutely bonkers in thinking we should have a colony there! (Even a small scientific base is silly; but a colony of millions? You'd have to have something wrong with you in the first place to want to live in a hellhole like that.)

Chris is ABSOLUTELY RIGHT. It is just UNBELIEVABLE to me that there are so many SAPS who live in a fantasy land.

geckzilla · Post by **geckzilla** » Sat Oct 07, 2017 12:47 am

I mean, he has indicated he wants to *die* on Mars...

Chris Peterson · Post by **Chris Peterson** » Sat Oct 07, 2017 12:51 am

geckzilla wrote:I mean, he has indicated he wants to *die* on Mars...

That's got to be really easy!

geckzilla · Post by **geckzilla** » Sat Oct 07, 2017 1:08 am

Chris Peterson wrote:
geckzilla wrote:I mean, he has indicated he wants to *die* on Mars...
That's got to be really easy!

Perhaps, assuming expiration does not occur by any number of ways prior to landing. I suppose death by crash landing counts. Of course, if things go awry, Earthlings might not even know what happened. We should be able to spy a crash sight with an observation satellite if those are still around, but we wouldn't know if he died before impact. Maybe Elon will have time to set up a communications network to radio back to Earth during descent. That would make things less ambiguous. I'm sure he's thought of it.

Starship Asterisk*

APOD: Global Aurora at Mars (2017 Oct 06)

APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)

Re: APOD: Global Aurora at Mars (2017 Oct 06)