Sexe local cam4 - Dating on the earth

Since the planet Earth doesn't have a birth certificate to record its formation, scientists have spent hundreds of years struggling to determine the age of the planet.

The nearest body to Earth, the moon, does not suffer from the resurfacing problems that cover Earth's landscape.

As such, rocks from early lunar history should be present on the moon.

The oldest rocks on Earth found to date are the Acasta Gneisses in northwestern Canada near the Great Slave Lake, which are 4.03 billion years old.

Rocks older than 3.5 billion years can be found on all continents.

Samples returned from the Apollo and Luna missions revealed ages between 4.4 and 4.5 billion years, helping to constrain the age of Earth.

In addition to the large bodies of the solar system, scientists have also studied smaller rocky visitors to that fell to Earth. Some are cast off from other planets after violent collisions, while others are leftover chunks from the early solar system that never grew large enough to form a cohesive body.In 1953, Clair Cameron Patterson measured ratios of lead isotopes in samples that put tight constraints on Earth's age.The Canyon Diablo meteorite is important because it represents a class of meteorites with components that allow for more precise dating.Research groups in Australia found the oldest mineral grains on Earth.These tiny zirconium silicate crystals have ages that reach 4.3 billion years, making them the oldest materials found on Earth so far. The rocks and zircons set a lower limit on the age of Earth of 4.3 billion years, because the planet itself must be older than anything that lies on its surface.Samples of the meteorite show a spread from 4.53 to 4.58 billion years.

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