Science and Space

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Oldest known piece of Earth

For the first time ever, the public have a chance to see at the University of Wisconsin-Madison a tiny speck of zircon crystal that is barely visible to the eye is believed to be the oldest known piece of Earth at about 4.4 billion years old. With the aid of a microscope, anyone has a chance to check out the tiny grain, which measures less than two human hairs in diameter.

Analysis of the object in 2001 by John Valley, a UW-Madison professor of geology and geophysics, startled researchers around the world by concluding that the early Earth, instead of being a roiling ocean of magma, was cool enough to have oceans and continents — key conditions for life.

Valley found that the planet had cooled to about 212 degrees Fahrenheit (100 degrees Celsius) less than 200 million years after it was formed. Before the research, the oldest evidence for liquid water on the planet was from a rock estimated to be much younger — 3.8 billion years old.

After the festivities the object will return to its native Australia with Simon Wilde, professor at Curtin University of Technology in Perth, Western Australia, who made its discovery in 1984. The sample will eventually be put on display at a natural history museum in that country.

posted by: kyawoo at 22:16 | link | comments (1) |
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#1  09 April 2005 - 23:09

 

It is interesting that the early Earth could have been cool enough to form oceans and continents. If it is true, a lot of rethinking will need to be done on the state of the early solar system, and the formation of the other planets. Wonder what the state of Mars and Venus would have been like?

Anonymous

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