Ca-Al-rich_inclusions
Calcium–aluminium-rich inclusion
Asteroid with an inclusion with high quantities of calcium and aluminium
A calcium–aluminium-rich inclusion or Ca–Al-rich inclusion (CAI) is a submillimeter- to centimeter-sized light-colored calcium- and aluminium-rich inclusion found in carbonaceous chondrite meteorites. The four CAIs that have been dated using the Pb-Pb chronometer yield a weighted mean age of 4567.30 ± 0.16 Myr.[1][2] As CAIs are the oldest dated solids, this age is commonly used to define the age of the Solar System.