The most common rocks that fall to Earth are called chondritic meteorites, or chondrites. In fact, the Earth is probably made of them. These are some of the oldest rocks in the Solar System, some dating to its very origin at just over four and a half billion years old. And some of their internal material has remained largely untouched since that time.
That makes them extraordinary time capsules, since the Solar System underwent churning differentiation and other processes to reach its current form. It’s a bit like finding a still-living velociraptor: an opportunity to study a bygone era, largely uncontaminated by exposure to the interceding time.
But the amount of information the rocks provide really depends on whether their composition was typical of that of the early Solar System. In a new study, a group of researchers has found that the composition of the chondrites is probably a match for the cloud of gas and dust that condensed to create the Solar System.