[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
June 5, 2003
Home - Site Index - Site Search/Archive - Help
Welcome, dinogeorge - Member Center - Log Out
Go to Another Section ----------------------- CLASSIFIEDS Job Market Real
Estate Automobiles ----------------------- NEWS International National
Washington Business Technology Science - Environment - Space & Cosmos - Columns
Sports New York Region Education Weather Obituaries NYT Front Page
Corrections ----------------------- OPINION Editorials/Op-Ed Readers' Opinions
----------------------- FEATURES Arts Books Movies Travel NYC Guide Dining &
& Garden Fashion & Style Crossword/Games Cartoons Magazine Week in Review
Multimedia/Photos Learning Network ----------------------- SERVICES Archive
Classifieds College Book a Trip Personals Theater Tickets NYT Store NYT Mobile
NYTDigital Jobs at NYTDigital Online Media Kit Our Advertisers
NYTimes.com > Science
E-Mail This Article
Most E-Mailed Articles
TIMES NEWS TRACKER
Track news that interests you.
Researchers Change Opinion on Earth's Age
By THE ASSOCIATED PRESS
Filed at 4:46 p.m. ET
WASHINGTON (AP) -- The Earth became a major planetary body much earlier than
previously believed, just 10 million years after the birth of the sun,
Experts now believe that the inner solar system planets -- Mercury, Venus,
Earth and Mars -- actually began forming within 10,000 years after the nuclear
fires of the sun were ignited about 4.5 billion years ago, says Stein B.
Jacobsen, author of an analysis appearing Friday in the journal Science.
Early in its life, the sun was surrounded by clouds of dust and gas. This
material slowly clumped together into larger and larger pieces. Eventually,
enough was concentrated in four bodies to form the inner solar system planets.
Within 10 million years, the Earth had reached about 64 percent of its
present size and was the dominant planetary body within 93 million miles of the
Mercury and Venus orbit closer to the sun and Mars is farther out.
The final major event in the formation of the Earth, says Jacobsen, was
probably the collision with a Mars-sized planetary body. This huge smashup
many millions of tons of material to the Earth. Some material also went into
orbit of the Earth and evolved into the moon.
This massive collision, the final major event in the Earth's formation, is
thought to have happened about 30 million years after the sun was born.
An earlier analysis of some chemical isotopes in the Earth's crust had
concluded that the planet formed about 50 million years after the sun. But
said a reinterpretation of the data, along with new measurements of chemicals
in some types of meteorites, supports the conclusion that Earth's basic
formation came much earlier.
On the Net:
It's easy to follow the top stories with home delivery of The New York Times
newspaper. Get seven days of The Times from $2.90 a week.
That's 50% off the regular home delivery rate.
TOP NYTIMES.COM ARTICLES
Hamas Halts Truce Talks With Abbas
Unemployment Rate Rises to 9-Year High
Manila Rules Out Bases as U.S. Shifts Forces in Asia
French Troops Arrive in Congo War Zone
U.S. Agrees to Redeploy Troops Far From North Korea Border
TOP SCIENCE ARTICLES
Chinese Shipwrecks Yield Treasures and a Dispute
Scientists Say Flooding of Old Mine Will Derail Plan for Lab
Repair Plan for Reactor With Leaks
Senate Adds Rule to Energy Bill to Double Ethanol in Gasoline
New I.B.M. Supercomputer to Begin Its Weather Work
Corrections | Help | Back to Top