NASA image shows bizarre circular mound on Mars

We've seen quite a few pictures snapped beyond our own world — there's the recent Europa image, for example — and the newest shot from Mars is no different. What is unique is the natural structure it shows: a circular mound in an otherwise smooth landscape. NASA posted the image yesterday with a statement pondering what the feature might be, and it is leaning toward volcanism as being the cause. As always, we've the rest of the details available after the jump.

The image was posted by the NASA Jet Propulsion Laboratory, and it features a 1.2 miles wide circular island around what the space agency says is a smooth landscape of lava flows in the Athabasca region. Given the surrounding region, NASA speculates that volcanism might have had a role in forming the "island".

This isn't the only natural structure in the area like this, and NASA says they so far "continue to puzzle scientists". The particular one featured above was possibly made from lava beneath the ground's surface causing it to be pushed upward and extruded.

The exact answer isn't known yet at this point, however, and so the space agency says it will continue to investigate. The image was taken with the HiRISE instrument on the Mars Reconnaissance Orbiter, says NASA, one of six instruments available on the device.