Most of the Earth that we can see today is about two million years old. However, the formation of the planet is much older.
An American geochemist Clair Patterson was commissioned to measure lead from a type of rock on Earth and from an extraterrestrial meteorite. It was the 1940s. That meant much more than knowing the amount of lead hidden. His calculations would result in the geological age of the Earth. Patterson built a laboratory for the project, and the result gave it 4.55 billion years, with a margin of error of only seventy million years.
Patterson discovered something else. He observed that lead concentrations were higher at the sea surface than at the seafloor, and in snow than in the deeper icy layers.
The person responsible for all that extra lead came from gasoline. His fight against the oil companies led to the passage in 1970 of a landmark law, the Clean Air Act, which forced the withdrawal of leaded gasoline from the market.
NEW MEASUREMENTS OF THE AGE OF THE EARTH
Not all of the Earth is the same age. “It depends on what you mean by earth,” says Milan Pavich, a geologist with the United States Geological Survey. ‘The oldest sedimentary rocks are about 3.9 billion years old – they are in Greenland – and at one point they were land. That’s pretty close to the time the planet was formed. ‘ However, the one you have in the garden is much cooler.
“Most of the land that we can see today is about 2 million years old,” says Pacih. About 2 million years ago, there were two major changes on the planet, which caused the formation of new earth.
WHERE DID THE NEW EARTH COME FROM
Global cooling and drying made deserts larger, and sand storms distributed land across the globe. Meanwhile, glaciers began to spread out from the poles, crushing rocks, plants, and whatever else as they went.
Land is still being produced continuously, but in much smaller quantities. Beneath the soil surface, rocks react to rain and groundwater, slowly eroding and breaking up into smaller minerals.
“The earth and its origin are older than the stars”
So the earth is not that old. However, there is another way of looking at it. If we look for its origin, we must add many more years to our planet. As Pavich adds, much of what was left after the Big Bang was essentially dust, which then condensed to form stars and, later, planets. “If you think about it a bit,” he concludes, “the earth and its origin are older than the stars.”
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