How do scientists know how old a meteorite is?

Meteorites can be dated because they contain minerals with radioactive isotopes that decay at known rates. By measuring parent and daughter isotopes, scientists can calculate when the rock solidified. Many primitive meteorites give ages around 4.56 billion years, making them among the oldest materials in the Solar System. These ages help scientists estimate when the first solid bodies formed after the Sun began shining. Meteorites are especially valuable because they preserve early Solar System chemistry better than most Earth rocks do.