An achondrite which exploded over the Egyptian town of El-Nakhla (31° 19' N, 30° 21' E, on Jun. 28, 1911, breaking into about 40 fragments, one of which allegedly (though this has never been proved) killed a dog. The Nakhla meteorite was later identified as belonging to an exclusive group of objects, known as SNC meteorites, a subgroup of which is the nakhlites, which are believed to have come from the surface of Mars.
The igneous rock of which the Nakhla is largely composed has been dated at 1.3 billion years. However, based on the age of clay found inside the specimens examined, it is thought that this rock was exposed to water about 600 million years ago.
One of the fragments, a well-preserved 12-centimeter-wide specimen, in 1999 joined ALH 84001 at the center of an intense debate concerning the nature of structures said by a team of NASA researchers to be the remains of microscopic martian life.
Update
Carbon-rich dendritic material in the Nakhla meteorite
Feb. 8, 2006: New evidence emerged that the Nakhla meteorite might contain evidence of past martian life. In a sample of the meteorite held by London's Natural History Museum, researchers found a carbon-rich substance filling cracks within the rock. The material resembles that found in veins apparently etched by microbes in volcanic glass from the Earth's ocean floor. Initial measurements suggest that the carbonaceous material did come from Mars and is not contamination from Earth. The research team includes members who brought evidence for microbial life in ALH84001. Details were presented at the 37th Lunar and Planetary Science Conference in March 2006 in Houston, Texas.
