Researchers have been conducting a study on a mysterious meteorite that exploded over Sudan in 2008. The meteor was estimated by NASA to weigh about nine tons and to be nearly 13-foot in diameter when it was spotted before impact. After the meteorite entered the atmosphere and impacted the planet’s surface, researchers went to the Sudanese desert to collect its remains for study. One of those fragments suggests that the meteor likely broke off from a massive asteroid approximately the size of the dwarf planet Ceres.
Ceres is the largest object in the asteroid belt. The meteorite is known as Almahata Sitta (AhS) and is made of a material known as carbonaceous chondrite. The image above is of a section of the meteorite in false color. The makeup of the space rock provides researchers clues about the parent asteroid that birthed a given meteor.
An asteroid’s makeup can tell scientists how an asteroid was formed. In this study, the team analyzed a 50 milligrams sample of AhS under a microscope and discovered that it had a unique mineral makeup. Minerals in the asteroid were discovered to have formed at intermediate temperatures and pressures, higher than what you’d expect to find in a typical asteroid but lower than what you would find inside of a planet.
One of the minerals was particularly puzzling and is known as amphibole and requires prolonged exposure to water to form. That particular mineral has only been discovered once in another meteorite. The high content of amphibole suggests that the fragment researchers are studying broke off from a parent asteroid that has never deposited meteorites on Earth before.
Many more fragile minerals are unable to survive the entry into Earth’s atmosphere. Researchers on the study also mentioned they expect the asteroid samples bought back from Ryugu by JAXA will reveal minerals that rarely turn up in meteorites on Earth.