APOD: A Hole in Mars (2012 Jul 18)

[APOD Robot]

A Hole in Mars

Explanation: What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers.

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[georgevedwards]

Remember the 50's Sci-Fi movie, "Invaders From Mars"? There is scene where the parent/s of a little boy walk over a hill and a hole in the sand swallows them up, they return as having been
taken over by a Martion "parasite", identifiable by a mark on the back of the neck. The boy claims they are not his parents, but no one believes him. This is proof! The movie was
based on fact!

[MosselKots]

Hey, I had just posted this one here as an alternative for the dancing video everybody (including me a bit) was complaining about...
Good stuff...
There used to a couple more of caved in caves and/or sinkholes on HiRISE, but I can't seem to find them anymore on the restyled site..

[Scabulus]

I love it! We need to all check the back of our necks!

As far as an scientific analysis that there is more likely to be life in the hole than elsewhere on Mars, consider that life on Earth exists in the most stable environments that have lots of water. Though there is life in giant holes in the Earth, those ecosystems are limited. Applying that observed principal to Mars suggests that there is a reduced probability of finding life in a hole in the ground. Has anybody done a timeline analysis on Mars to figure out if it had a primordial soup period and had an atmosphere hanging around long enough for some microbial life to develop? If so, then we should be finding places to look for fossils instead of trying to find something still alive.

[wildblueyonder]

Definitely a sand-worm hole (Dune) or sarlacc pit (Star Wars)

[nebosite]

Sarlacc's Lair!!!
http://starwars.wikia.com/wiki/Sarlacc

[Boomer12k]

This appears to be a 114.829 FOOT crater...on the side of Pavonis Mons...it appears to be a lava tube...I doubt it ever harbored life...got long standing water?

More info from another Article...

http://nssphoenix.wordpress.com/2011/09 ... n-on-mars/

"Crater on the flank of Pavonis Mons on Mars
Image Credit: NASA / JPL / University of Arizona

Earlier this year, NASA’s Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) captured an image of a crater with a block dot in the center on the slopes of the Pavonis Mons volcano. Mission managers decided to have another look, this time with the High Resolution Imaging Science Experiment (HiRISE).

The black dot turned out to be a skylight 35 meters across leading into a cavern below. The cavern is likely a lava tube located beneath the surface of the volcano. Based on the shadow, the floor is about 20 meters below the skylight.

Speculation centers on the formation of the crater. It could be a sink hole formed from the loose dust on the volcano flowing into the cavern when the roof collapsed. In this closeup, one can see how the walls of the crater have slumped and material has flowed into the cavern below.

The hole might also be from a small meteorite that punched a hole through the lava tube. There does not seem to be much (if any) rim from a meteorite strike and the crater it would have created. Then, there is speculation that the underground cavern is a former ice deposit that has been exposed and sublimated into the Martian atmosphere.

Later this year, the HiRISE mission plans another image of the crater, creating a stereo picture that may help resolve the mystery."

Should have a picture of Pavonis Mons, and the location of this "pimple"...

:---[===] *

[Moonlady]

looks like Martians live in igloos with an on the top entrance , was this picture taken at the poles of MArs?

[FLPhotoCatcher]

That looks a lot like a sinkhole, though the cavern must be quite large to hold all the sand that fell in, and still have room for more.

And on an unrelated note, I noticed that more and more people everywhere are not bothering to type the word "be" where there should be one in a sentence. For example, MosselKots said, "There used to a couple more of caved in caves and/or sinkholes..." Is this a European thing, or are some 'experts' trying to change our grammar? Just wondering. It is definitely clearer with it, and so sometimes reads faster.
Here's one example I just thought of where "be" makes a big difference:
He used to upset with the chair.
He used to be upset with the chair.

To be, or not to be...

[JeffGee]

I'm confused by the claims of uncertainty about the larger circular feature. Looks like a pretty standard impact crater to me.

[Beyond]

Just goes to show that nothing is perfect. Even mars has Zits.

[starstruck]

I find it interesting how the brain can be tricked by the perspective in photos from above like this. At first it looked like a conical mound projecting above the surrounding surface, which reminded me of a Chameleon's eye. Then it swapped around visually and I could see it as a depression in the surface, which now makes me think there may be giant Martian Trapdoor Spiders . . . don't go near the edge!

[MosselKots]

On the be-thing;
Definitely not intentional! =]
I've always had this, sometimes when writing/typing my brain gets ahead of me and I skip a word (or letter/syllable when handwriting)
Some sort of reversed dyslexia or something, I guess... Luckily (for me) it doesn't happen often though =]
Also, English is my second language. (I'm Dutch.) Maybe why I missed it...

On the cave;
I think I read on HiRISE that the Mars-boffins think it's an impact crater that caused the cave-in, so I guess the cave itself isn't necessarily big enough to house all the sand/dust, as most of would have been ejected away.

My 2cts,
mK

[neufer]

Click to play embedded YouTube video.

[orin stepanek]

Just goes to show that nothing is perfect. Even mars has Zits.

reminded me of a zit also!
Hey1 did you see the topic of speculation?

Click to view full size image

Now isn't that cute!
If they send Explorers to investigate; they'll need to send spelunkers!

[Coyne Tibbets]

Totally ruined: The Mars property has a sinkhole and now must be regarded as worthless.

[dan]

It reminds me of a bb hole in a window. Maybe we should look for an entry hole on the other side of the planet.
http://www.flickr.com/photos/wouldpkr/4846381539/

[no one you know]

Reminds me of a salt dome here on earth...the water that helped form it long gone..the crater was formed when the water ran out..Seen pleanty of this here on this planet.

[neufer]

Why is there no indication of the whitish material having fallen down into the hole?

[Dave-O]

Looks like a *very* large Ant Lion hole. Wonder what it eats?

[Hubba Bubba]

Why is there no indication of the whitish material having fallen down into the hole?

In the photo, the sunlit portion of the cavern floor appears to be the same color as the sides of the crater. Whitish-grey.

[geckzilla]

There's less light reaching inside the hole so it appears darker. There floor of the cavern might also be a mound shape rather than flat it would be even less illuminated from that side if so.

[neufer]

Looks like a *very* large Ant Lion hole. Wonder what it eats?

• . http://asterisk.apod.com/viewtopic.php? ... 11#p179911
  
  . http://www.marzipanworld.com/acatalog/M ... _Ants.html

[FloridaMike]

Why is there no indication of the whitish material having fallen down into the hole?

In the photo, the sunlit portion of the cavern floor appears to be the same color as the sides of the crater. Whitish-grey.

If this is a sink hole type situation I'd imagine that the "floor" we see in the hole is actually the top of a mound of material, equal in volume to the crater we see on the surface. However, the material in the hole does appear to be darker in composition. Maybe it has absorbed moisture?

The 3 O'Clock area of the outer crater/sink hole appears to be slightly lifted, which would make it NOT a sink hole. Anyone see the same thing or am I seeing inside-out again?

[MosselKots]

Found the other Mars pits I was talking about...

http://hirise.lpl.arizona.edu/PSP_009488_1745
and:
http://hirise.lpl.arizona.edu/PSP_003647_1745 / http://hirise.lpl.arizona.edu/PSP_004847_1745

these are even more mysterious (to me anyway), as they are too deep to see the botttoms...
mK