NASA's Opportunity rover celebrated its 10th anniversary on Mars by finding an object unlike anything ever seen before on the Red Planet.

Scientists confirmed this week that a rock that looks like a jelly doughnut has been discovered on Mars and they're close to figuring out how it got there in the first place, according to AFP.

The object appeared in different locations in pictures taken 12 days apart by NASA's Opportunity rover. 

"It looks like a jelly doughnut, white around the outside, red in the middle," said Steve Squyres, the principal investigator of the Mars Exploration Rovers, according to AFP.

Squyres said the object has a "weird deep red color," but not a Martian red like the rest of Mars.

"We have looked at it with our microscope. It is clearly a rock," said Squyres to reporters during a briefing to celebrate 10 years since Opportunity landed on Mars.

The rock has been called "Pinnacle Island," according to Squyres.

Scientists have said the rock likely moved when the rover did a pirouette turn in the Martian soil and hit a chunk of bedrock that rolled downhill, according to AFP.

"We think that in the process of that wheel moving across the ground, we kind of flicked it, kind of tiddly winked it out of the ground and it moved to the location where we see it," Squyres said.

Opportunity landed on Mars on Jan. 24, 2004, and its counterpart, Spirit, landed on Jan. 3 on the other side of the Red Planet.

Missions designed for both rovers were supposed to last just 90 days, yet ten years later Opportunity is still providing NASA with data.

See Now: OnePlus 6: How Different Will It Be From OnePlus 5?