If it was a real pie, it'd be the largest in the universe. But alas, it's composed of cold iron-rich rock -- not flour, butter, fruit and sugar. The 1.2-mile wide circle of rumpled Martian crust was likely created by lava flows thousands of years ago.

Captured by the HiRISE camera -- one of six instruments on NASA's Mars Reconnaissance Orbiter -- the strange landform is located in the Athabasca region, an area known for possessing some of the youngest Martian lava flows.

"Perhaps lava has intruded underneath this mound and pushed it up from beneath," NASA officials at the Jet Propulsion Laboratory, in California, wrote in a statement last week. "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."

Scientists say the Athabasca region is populated by a number of puzzling geologic features. A few of them have compelled researchers to suggest Mars may still be volcanically active.

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