NASA’s Opportunity Rover Sends Mysterious Spherical Rock Images From Mars

NASA's Opportunity rover has sent an image of spherical rock formations on Mars that do not resemble the Martian blueberries.

Opportunity rover is one of the two rovers that landed on Mars (the other being Spirit) in 2003. While the researchers expected the rovers to function for just 90 days until April 2004 after completing their mission, both the rovers have worked for years. Spirit stopped sending signals in 2010, but Opportunity is still amazingly in good working condition and sending out images of the Mars surface, according to NASA.

Opportunity is currently probing an outcrop known as Kirkwood located in Cape York segment of the western rim of crater called Endeavour. It beamed back a photo of spherical rocks of about one-eighth of an inch (3 millimeters) in diameter that were taken by a microscope-like imager on its robotic arm. The rover sent four different images of the mosaic which were later joined by the scientists to study and analyze.

This is not the first time that the rover is sending images of spherical rocks. Earlier in 2004, it sent images of concretions that were formed when minerals in water precipitate and settle in sedimentary rocks.

Scientists named the rocks as Martian blueberries at many sites on Martian soil. At first, the new image sent by Opportunity resembled the blueberries, but experts noticed that the rocks have a different structure and composition. Their preliminary analysis indicated that the rocks do not have iron content that are found in Martian blueberries.

"This is one of the most extraordinary pictures from the whole mission," Opportunity's principal investigator, Steve Squyres of Cornell University in Ithaca, N.Y., said in a statement from NASA.

"Kirkwood is chock full of a dense accumulation of these small spherical objects. Of course, we immediately thought of the blueberries, but this is something different. We never have seen such a dense accumulation of spherules in a rock outcrop on Mars," he said.

While the experts are still analyzing the rocks, they have already chosen the next stop for Opportunity rover to perform its science operations. After completing its mission on Endeavour crater, the rover will head to a pale-toned outcrop nearby Kirkwood to detect any signs of clay minerals.

The Martian conditions will also be favorable for the rover as spring equinox will come to Mars this month that could provide more sunshine for Opportunity's solar power.

As Opportunity continues its work, another Mars rover Curiosity that landed on the Red planet on Aug. 5 will perform scientific operations while on its journey to a site known as Glenelg to find out if it could possibly support microbial life.