Our Moon is at least 4.51 billion years old: study
- Moon is at least 4.51 billion years old — up to 140 million years older than previously thought, according to new study of minerals called zircons brought back from the lunar body to the Earth by the Apollo 14 mission in 1971.
- The Moon’s age has been a hotly debated topic.
- The Moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia.
- The new study would mean that Moon formed “only” about 60 million years after the birth of solar system, providing critical information for astronomers and planetary scientists who seek to understand the early evolution of the Earth and our solar system.
- It is usually difficult to determine the age of Moon rocks because most of them contain a patchwork of fragments of multiple other rocks.
- Zircons are nature’s best clocks. They are the best mineral in preserving geological history and revealing where they originated.
- The Earth’s collision with Theia created a liquefied Moon, which then solidified. Scientists believe most of the Moon’s surface was covered with magma right after its formation.
- The uranium-lead measurements reveal when the zircons first appeared in the Moon’s initial magma ocean, which later cooled down and formed the Moon’s mantle and crust; the lutetium-hafnium measurements reveal when its magma formed, which happened earlier.