About 4.5 billion years ago, a large object struck the young Earth. Pieces of rock were thrown into space and later joined to form the Moon. Scientists call the destroyed object Theia.
A new study by researchers at several universities looked for clues in isotopes. Isotopes are small chemical differences that act like fingerprints for where material formed in the early solar system. The team measured iron and also used earlier isotope data from rocks and meteorites, including six lunar samples returned by the Apollo missions.
The researchers ran simple computer models and found that Theia most likely formed closer to the Sun than Earth did.
Difficult words
- isotope — a version of an element with different massisotopes
- fingerprint — a mark or signal that shows origin or identityfingerprints
- meteorite — a space rock that falls to Earth's surfacemeteorites
- sample — a small piece taken for study or testsamples
- model — a simple computer plan or simulationmodels
- measure — to find the size or amount of somethingmeasured
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Discussion questions
- Why do researchers study isotopes in rocks and meteorites?
- How can samples from the Moon help scientists learn about the past?
- Would you like to learn more about the Moon? Why or why not?
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