Mysterious Circular Landform on Mars

NASA scientists are searching for an explanation for a strange circular feature, approximately 2 km (1.2 miles) in diameter, located in the Athabasca Valles region of Mars that was imaged by the Mars Reconnaissance Orbiter's HiRISE camera.

Image source: NASA/JPL-Caltech

This enigmatic "island" stands in stark contrast to the flat "sea" of the surrounding plain and is thought to be a result of volcanism though the exact mechanism behind its formation has yet to be described.

From the NASA JPL release:

Perhaps lava has intruded underneath this mound and pushed it up from beneath. It looks as if material is missing from the mound, so it is also possible that there was a significant amount of ice in the mound that was driven out by the heat of the lava. There are an array of features like this in the region that continue to puzzle scientists.

We hope that close inspection of this HiRISE image, and others around it, will provide some clues regarding its formation.

It's an interesting image and when I saw it in the CNET article on my feed this morning, my first thought was that it looked a bit like a cell on a slide though the CNET article compares it to a waffle (an Eggo I'd assume) and NBC News likened it to a giant cookie.


A sci-news.com article contained a larger image, showing more of the surrounding terrain, which can viewed here.

Certainly an interesting image, but it appears to me to be an impact crater that may have simply filled with molten material afterward.

I'm no scientist, so I'll defer to those that know better, but that's my take on its origins.

The full hirise shot makes it look like someone put a giant cigarette out on mars

Something launched I think.
It looks melted.

Maybe volcanic activity under a large amount of ice? Or maybe there was a large caldera that was eroded by an ocean?

+1 for lava. Something smacked Mars and Mars filled it in with lava.

Notice how the ridges all connect.

Reminds me of an underground tunnel system.

It's a very interesting formation, what ever it is.

It's also appears to have already been posted a few days ago.

Mars becomes more interesting by the day.

a reply to: theantediluvian
Mars has a belly button, nice find, interesting.

originally posted by: cavtrooper7
Something launched I think.
It looks melted.

I think you are looking at it wrong -- you have your "innies and outies" mixed up. Here is what it should be:

It looks like something hot was boiling under the land, and it inflated. Somehow, it leaked its hotness in a non-explosive manner, and the land, stretched like a pregnant woman's belly gently fell back in place, but becoming rippled because it was so much stretched.

Best idea I could think of. Where is my prize now NASA? lol

But it probably happened that way.

Looks like my last attempt at cooking rice. For some reasons large bubbles formed then deflated over the surface of the water.

Perhaps whatever it was that hit the surface, melted underground layers of water and gas, these re-condensed onto the surface dust and dirt forming a bubble, which then collapsed on itself?

a reply to: Soylent Green Is People
Try it this way.

Mars has a belly button!

Seriously tho, how big is that thing and how is it so amazingly circular?
Looks stamped with a biscuit cutter, it's so round.

originally posted by: Phage
a reply to: Soylent Green Is People
Try it this way.

Yeah, that makes much more sense Phage. Thank you for the pic.

Looks a heck of a lot more natural.

a reply to: Phage

That definitely makes it easier to differentiate the higher areas from the lower ones. What I'm wondering about is the height of the raised (I assume them to be anyway) portions relative to the surrounding landscape. I've seen it described as a mound in some articles so I'm picturing it as a sort of blister with fissures running through it.

a reply to: Phage

Very good. I sometimes forget that trick (it also works for moon craters that people think are domes).

looks similar to an Icelandic sub-glacial volcano

a reply to: Phage

I couldn't, for love or money, see it 'inverted' until you rotated it. Now I can't see it the other way, lol. It's like an optical illusion.

Someone put a really large coffee cup down on the planet. That's why all the mounds formed within the inner ring like sand castles. If you look closely at the liquifaction around the rim you can clearly see it's just coffee stain.