Can meteorites tell us how the Sun was born?
Yes. Isotopes in meteorites suggest the Sun formed in a cluster of stars, possibly near massive stars that added short-lived radioactive elements.
The Sun formed about 4.57 billion years ago, and no record of its birth survives on the Sun itself. Meteorites, however, preserve clues about its birth environment.
Short-lived isotopes. CAIs and other early materials contained aluminium-26, iron-60 and other short-lived radioactive isotopes. Aluminium-26 was relatively abundant. Because these isotopes decay quickly, they must have been made shortly before the Solar System formed, within a few million years. Possible sources include massive stars, which make aluminium-26 and release it in powerful winds, supernovae, or radiation from the young Sun itself. Many scientists think the Sun formed in a cluster of stars, possibly near massive stars that enriched the cloud.
Presolar grains. Grains formed around other stars before the Sun show that the Sun's birth cloud contained material from many earlier stars, including red giants and supernovae.
Isotopic variations. Small differences in isotopes between meteorite groups indicate that material from different stellar sources was not perfectly mixed, suggesting that new material may have been added as the Sun formed.
Oxygen isotopes. The Sun is rich in oxygen-16 compared with Earth and most meteorites, as measured by the Genesis mission. This suggests processes such as ultraviolet light from the young Sun or nearby stars altered oxygen isotopes in the disc.
Beryllium-10. Evidence of beryllium-10 in CAIs suggests that intense radiation from the young Sun bombarded nearby material.
Together, these clues paint a picture of the Sun forming in a busy stellar nursery rather than in isolation.