Shortcut Navigation:
B.3.1. How do we know- determining the age of CAIs

How do we know? Determining the age of CAIs

How do we know? Determining the age of CAIs

  • Exhibition Text

    • How do we know that calcium-aluminum inclusions, or CAIs, are the oldest rocks that formed in our solar system? In a technique somewhat like the radiocarbon dating method used on fossils, researchers measure the amounts of certain forms, or isotopes, of the elements uranium and lead present in CAIs. Isotopes of uranium undergo radioactive decay to form lead at known rates, providing a clock that can be used to date material from the early solar system. These studies indicate that the oldest CAIs formed 4.568 billion years ago—less than one million years after our Sun first ignited.

      Show more
  • For Educators

    • Topic: Earth Science

      Subtopic: Meteorites

      Keywords: Astrogeology, Astrophysics, Chondrites (Meteorites), Radioactive dating, Solar System--Origin

      Audience: General

American Museum of Natural History

Central Park West at 79th Street
New York, NY 10024-5192
Phone: 212-769-5100

Open daily from 10 am - 5:45 pm
except on Thanksgiving and Christmas
Maps and Directions

Enlighten Your Inbox

Stay informed about Museum news and research, events, and more!