The meteorites studied were 'carbonaceous chondrites
' - space rocks that originated from asteroids that are as old as our Solar System.
We're pretty sure we have plenty of meteorites from these types of primitive asteroids--the carbonaceous chondrites
. But meteorites we collect here on Earth have complicated pasts and don't usually come with "Made in X" labels on them.
Wang, "Short-lived chlorine-36 in a Ca- and Al-rich inclusion from the Ningqiang carbonaceous chondrite
," Proceedings of the National Academy of Sciences of the United States of America, vol.
, which are thought to have delivered lots of water to the early Earth, make up less than 3 percent of known meteorites.
"Hydrogen Isotopse in Lunar Volcanic Glasses and Melt Inclusions Reveal a Carbonaceous Chondrite
Heritage." Science published online 9 May 2013.
Meteorite hunters eventually recovered between 5 and 10 kilograms of a carbonaceous chondrite
The Allende meteorite is the largest carbonaceous chondrite
, a diverse class of primitive meteorites, ever found on our planet and is considered by many the best-studied meteorite in history.
The forms of oxygen in the sample, described earlier this year in the Proceedings of the National Academy of Sciences, clearly identified the rock fragment as a CV3 carbonaceous chondrite
, coming from an asteroid born during the earliest days of the solar system, 4.5 billion years ago.
It was however closer to that sometimes found in a type of meteorite known as a carbonaceous chondrite
Like the other C-type asteroids, Hygiea's surface material is similar to ancient, relatively unaltered carbonaceous chondrite
The 'carbonaceous chondrite
meteorite' was originally formed in the early solar system when microscopic dust particles gathered around larger grain particles called chondrules, which were around one mm in size.
Sediments from the crater indicate that the impactor must have been a carbonaceous chondrite
, an especially primitive meteorite.