Mar. 17, 1998 214 million year-old event corresponds with mass
extinction A team of scientists working on two continents has
discovered that a series of five craters on Europe and North
America form a chain, indicating the breakup and subsequent
impact of a comet or asteroid that collided with Earth
approximately 214 million years ago. The impacts may have
contributed to a mass extinction that occurred at the end of the
Triassic period–one of the five greatest mass extinctions in
history. The work, by scientists at the University of Chicago,
the University of New Brunswick (Canada) and The Open University
(Milton Keynes, U.K.) is published in a paper in the Thursday,
March 12, issue of the journal Nature. “When scientists observed
the impacts of the pieces of Comet Shoemaker-Levy 9 on Jupiter
in July 1994, they said that the impact of a fragmented comet
could never happen here on Earth because the Earth’s
gravitational field is too weak to break a comet into pieces,”
said David Rowley, University of Chicago A