age of the Earth

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age of the Earth

The oldest rocks found in the Earth's crust have been assigned ages of 3.96 billion (109) years from radioisotope studies, but other properties of the rocks support the belief that the planet shares a common origin with the rest of the Solar System, about 4.57 billion years ago. The cycling of the crustal material by plate tectonics (see Earth) and the eroding effects of ice, water, and wind mean that none of the earliest rocks survive intact and that evidence of an early meteoritic bombardment, so apparent on the Moon, Mercury, and Mars, is absent. See Earth; Solar System, origin.
References in periodicals archive ?
The American public already has difficulty accepting scientific facts about climate, evolution, and the age of Earth.
In fact, chemical and biological conditions in this middle age of Earth history were sufficiently static to earn this interval an unflattering nickname-'the boring billion.
If Earth were compressed into 24 hours If the age of Earth compressed into then the first humans would appear just 40 seconds before midnight.
It is about four billion years old, just 500 million years younger than the estimated age of Earth.
That's the consensus of two independent research teams that used the same radioactive-dating technique to estimate the age of Earth and some of its neighbors.
Hugh Strawn, who works for the alliance's sister organization, the Property Loss Research Bureau, contends that the global-warming theory is based on data that is only 100 years old and that it is an infinitesimal period of time compared with the age of Earth.
Thoreau nurtured a passion for the wild age of Earth and gave it voice.
From that, he estimated the maximum age of Earth at about 5.