Huge Meteorite on Mars Discovered by NASA's Curiosity Rover
This photo by NASA's Curiosity Mars rover shows the huge iron meteorite "Lebanon" (7 feet wide) and its smaller companion "Lebanon B." The two meteorites were found by Curiosity on May 25, 2014. The circular insets are more detailed views by Curiosity's Chem-Cam instrument overlaid on an image by the rover's Remote Micro-Imager.
Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS

Talk about a speed bump. NASA's Mars rover Curiosity has discovered its first meteorite on the Red Planet, and it's no puny space rock.

The newfound Mars meteorite, which scientist have named "Lebanon," is nearly 7 feet (2 meters) wide and made of iron. Photos of the meteorite taken by Curiosity also revealed a smaller companion nearby, which is now dubbed "Lebanon B."

"That 'Lebanon' is huge, almost 7 feet," said NASA spokesman Guy Webster from the agency's Jet Propulsion Laboratory in California. While NASA released a detailed photo of the Lebanon meteorites Tuesday (July 15), the Curiosity rover actually discovered the space rocks on May 25. [Mars Meteorites Found on Earth (Photos)]

This photo by NASA's Curiosity rover on Mars shows three meteorites on the Martian surface, the rover's first space rock discoveries, found on May 25, 2014. The larger meteorite in the foreground is "Lebanon" (7 feet wide) and has a smaller companion, "Lebanon B". The third meteorite, seen behind and to the right of Lebanon, is also 7 feet wide.
This photo by NASA's Curiosity rover on Mars shows three meteorites on the Martian surface, the rover's first space rock discoveries, found on May 25, 2014. The larger meteorite in the foreground is "Lebanon" (7 feet wide) and has a smaller companion, "Lebanon B". The third meteorite, seen behind and to the right of Lebanon, is also 7 feet wide.
Credit: NASA/JPL-Caltech

Webster said Curiosity also found a third meteorite at the same time it spotted the Lebanon rocks. In a raw, unprocessed photo from Curiosity, the third meteorite — which is also about 7 feet wide — can be seen just beyond the closer Lebanon meteorites.

"Heavy Metal! I found an iron meteorite on Mars," Curiosity's handlers wrote on the mission's Twitter page.

Altogether, the three meteorites are the first space rocks on Mars discovered by the Curiosity rover since it landed on the Red Planet in August 2012, Webster added.

Curiosity snapped detailed photos of the main Lebanon meteorite using its high-resolution Chem-Cam and Remote Micro-Imager cameras. The images revealed strange angular cavities in the surface of the rock.

"One possible explanation is that they resulted from preferential erosion along crystalline boundaries within the metal of the rock," NASA officials wrote in a statement. "Another possibility is that these cavities once contained olivine crystals, which can be found in a rare type of stony-iron meteorites called pallasites, thought to have been formed near the core-mantle boundary within an asteroid."

NASA's Curiosity rover — the centerpiece of NASA's $2.5 billion Mars Science Laboratory (MSL) mission — landed on Mars Aug. 5. How much do you know about Curiosity and its mission?
Artist’s concept depicts the NASA Mars Science Laboratory Curiosity rover, a nuclear-powered mobile robot for investigating the Red Planet’s past or present ability to sustain microbial life.
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A 'Curiosity' Quiz: How Well Do You Know NASA's New...
NASA's Curiosity rover — the centerpiece of NASA's $2.5 billion Mars Science Laboratory (MSL) mission — landed on Mars Aug. 5. How much do you know about Curiosity and its mission?
Artist’s concept depicts the NASA Mars Science Laboratory Curiosity rover, a nuclear-powered mobile robot for investigating the Red Planet’s past or present ability to sustain microbial life.
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Meteorites have been discovered by Spirit and Opportunity, two smaller NASA rovers that landed on Mars in 2004. Opportunity is still active today, though its twin Spirit gave up the ghost in 2011.

On Aug. 5, Curiosity will celebrate its second Earth-year anniversary on Mars. Since landing in 2012, the rover has found evidence that Mars could have been habitable for primitive life — a major mission goal —and has been making its way toward the huge Mount Sharp, which rises from the center of its Gale Crater landing site.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original story on Space.com.