It’s not the first meteorite found on the Red Planet, but it’s sure the largest. A 6-foot-long (2 meters) iron meteorite named ‘Lebanon’ was spotted by Curiosity’s cameras poking its head out of the Martian soil on May 25th. NASA released the stunning portrait this afternoon.
With its gunmetal sheen and numerous ‘thumbprints’ it looks identical to many fresh iron meteorites found on Earth. Those Swiss cheese-like holes called regmaglypts form in a couple different ways. Softer, less heat resistant minerals like iron sulfide (troilite) riddle some iron meteorites.
During the plunge through a planet’s atmosphere, the surface of a meteoroid heats up, melts and gets sculpted by powerful, super-heated air. Softer materials melt away or ‘ablate’, giving the meteorite its classic thumbprint texture.
Martian winds and weather could also have eroded out the softer materials to create the cavities. Perhaps both processes were (and still are) at play. The circles are individual,high-resolution photos taken by Curiosity’s Remote Micro-Imager. When you click the image above, you’ll be able to explore the iron’s surface in great detail.
This is Curiosity’s first meteorite discovery and the 8th and largest found on the planet. The earlier generation Spirit Rover stumbled onto two potential meteorites – Allan Hills and Zhong Shan – inside Gusev Crater in 2006. They resembled those found by the rover’s twin, Opportunity, which uncovered five confirmed iron meteorites. Here’s Opportunity’s space rock booty to date:
* Heat Shield Rock – Found in 2005. Renamed Meridiani Planum meteorite for its location. Type: iron meteorite
* Block Island – 2009 / iron meteorite
* Mackinac Island – 2009 / iron meteorite
* Shelter Island – 2009 / iron meteorite
* Oileán Ruaidh - 2010 / iron meteorite
While irons aren’t the most common meteorite – stony meteorites are – they resist erosion better and stand out from the general rocks. That’s probably the reason all those found so far have been metallic.