APOD: MAVEN at Mars (2014 Sep 26)

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APOD: MAVEN at Mars (2014 Sep 26)

Post by APOD Robot » Fri Sep 26, 2014 4:06 am

Image MAVEN at Mars

Explanation: Launched on November 18, 2013, the MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft completed its interplanetary voyage September 21, captured into a wide, elliptical orbit around Mars. MAVEN's imaging ultraviolet spectrograph has already begun its planned exploration of the Red Planet's upper atmosphere, acquiring this image data from an altitude of 36,500 kilometers. In false color, the three ultraviolet wavelength bands show light reflected from atomic hydrogen (in blue), atomic oxygen (in green) and the planet's surface (in red). Low mass atomic hydrogen is seen to extend thousands of kilometers into space, with the cloud of more massive oxygen atoms held closer by Mars' gravity. Both are by products of the breakdown of water and carbon dioxide in Mars' atmosphere and the MAVEN data can be used to determine the rate of water loss over time. In fact, MAVEN is the first mission dedicated to exploring Mars' tenuous upper atmosphere, ionosphere and interactions with the Sun and solar wind. But the most recent addition to the fleet of spacecraft from planet Earth now in martian orbit is MOM.

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by bystander » Fri Sep 26, 2014 4:07 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by Boomer12k » Fri Sep 26, 2014 4:36 am

Interesting....lighter gas extends into space, but nearby....medium gas even closer, and it's Oxygen, AMAZING,...Even with the Solar Winds...which I thought would have blown it all away...surprised me. I did not think Mar's Gravity capable of holding on to much if anything light....it just is not enough to hold it in a close atmosphere.

Space is an amazing place of surprises and learning new things, and Man is an IDIOT.... :shock:

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by NGC3314 » Fri Sep 26, 2014 10:49 am

Hydrogen doesn't want to stay around on any of the inner rocky worlds in our solar system. There is a similar photograph of the Earth in the UV wavelength of hydrogen's Lyman alpha emission taken from the lunar surface during Apollo 16, using George Carruthers' UV telescope:

Image

This geocoronal emission is a nuisance for UV astronomy as far out as geosynchronous orbit. (Would the equivalent seen by MAVEN be areocoronal emission?)

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by geckzilla » Fri Sep 26, 2014 3:23 pm

NGC3314 wrote:(Would the equivalent seen by MAVEN be areocoronal emission?)
Hah, we really messed up by using the geo prefix in so many words. Geocentrism is alive in our subconscious.
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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by BDanielMayfield » Fri Sep 26, 2014 11:25 pm

I find it amazing that after 4.6 billion years Mars still has enough H2O in it's tenuous atmosphere for it to be still be outgassing like this.

Also, this has to be a real problem for hopes of terraforming Mars. Even if a great deal of water was brought to Mars via, say, hitting it with re-directed comets, this natural desiccation of Mars by solar effects would always be there...
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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by Chris Peterson » Fri Sep 26, 2014 11:31 pm

BDanielMayfield wrote:Also, this has to be a real problem for hopes of terraforming Mars. Even if a great deal of water was brought to Mars via, say, hitting it with re-directed comets, this natural desiccation of Mars by solar effects would always be there...
Not really a problem. It is a process that happens over hundreds of millions of years. That's not a timescale of importance to our species. If we could terraform Mars in a few decades or centuries, we'd end up with something good enough to last us for, effectively, forever.
Chris

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by geckzilla » Fri Sep 26, 2014 11:36 pm

Terraforming Mars is such a popular and fun topic. The only thing that really bothers me about it is how sure some people are we can radically alter the Martian atmosphere while simultaneously denying that we are doing the same thing by accident here on Earth. It'd be funny if it weren't so tragic.
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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by Chris Peterson » Fri Sep 26, 2014 11:43 pm

geckzilla wrote:Terraforming Mars is such a popular and fun topic. The only thing that really bothers me about it is how sure some people are we can radically alter the Martian atmosphere while simultaneously denying that we are doing the same thing by accident here on Earth. It'd be funny if it weren't so tragic.
Also, much of the knowledge that might allow us to terraform Mars is being acquired through the study of our own unplanned transformation of Earth's climate. An actual experiment in progress.
Chris

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Re: APOD: MAVEN at Mars (2014 Sep 26)

Post by Ron-Astro Pharmacist » Mon Nov 09, 2015 3:03 pm

Click to play embedded YouTube video.
I was hoping for an APOD to explain what we are actually seeing in the video.
Click to play embedded YouTube video.
CBS did a good job though I'd still like to have some parts explained.
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