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The so-called ‘Tunguska Event’ refers to a major explosion that occurred on 30 June 1908 in the Tunguska region of Siberia, causing the destruction of over 2000 km2 of taiga, globally detected pressure and seismic waves, and bright luminescence in the night skies of Europe and Central Asia, combined with other unusual phenomena. The ‘Tunguska Event’ may be related to the impact with the Earth of a cosmic body that exploded about 5–10 km above ground, releasing in the atmosphere 10–15 Mton of energy. Fragments of the impacting body have never been found, and its nature (comet or asteroid) is...

It's bad enough when, every few million years, an asteroid rocks our planet. It's worse if the impact triggers regional or global volcanic activity, which is not only hazardous to nearby plants and animals but can choke Earth's atmosphere with deadly gases for months or years. But there's also a possible bright side, like the birth of nice places like Hawaii. For more than three decades, scientists have explored the question of whether an asteroid impact could cause significant volcanic eruptions, hot spots that spring up out of nowhere and create new landforms or rearrange old ones. The process might...

Nearly a quarter-billion years ago, life on Earth almost disappeared. Called the Great Dying, the precise cause of why 70-90% of all terrestrial species might become extinct, challenges geologists, paleontologists and climatologists. But according to a recent study published in Science, astrophysicists who predict meteor orbits have a say in the outcome too. -------- The "Great Dying," a time of earth's greatest number of extinctions, appears to have been caused by the impact of a large meteor, according to a research team that includes Luann Becker, a scientist with the Institute for Crustal Studies in the Department of Geology at...

In 1989, Edward Bryant climbed a point on the southeast coast of his native Australia with a colleague and found an odd jumble of boulders well above the surf. A big wave, he thought, maybe a tsunami from an earthquake, must have tossed them up there. Over the next few years, however, the University of Wollongong geologist explored hundreds of miles of coast and found more signs of wave action, hundreds of feet above the water--too high for any quake-spawned surge. An astonishing hypothesis of devastation from outer space formed in his mind. It gathered some praise, along with many...

Auckland - The dinosaurs were probably heading for extinction even before an asteroid strike wiped them out 65 million years ago, New Zealand scientists said on Monday. Palaeontologist Chris Hollis and a team of scientists from the government-owned Geological and Nuclear Sciences (GNS) have uncovered evidence of significant global climate change even before the meteor strike. "An unknown number of species may have been in sharp decline when the asteroid struck and the impact winter probably finished them off quite quickly," Hollis said in a statement. He added: "There's no scientific agreement on what caused this climatic instability, but it's...

<p>Massive tsunamis, miles of raging forest fires, a stratosphere clogged with enough debris to obscure the sun -- even a relatively small asteroid striking Earth would wreak enough havoc to end civilization.</p> <p>"It's not whether it's going to happen," said Bruce Weaver, director of Monterey Institute for Research in Astronomy (MIRA). "The question is how long it will be (until one hits)."</p>

The headline read: "Massive tsunami sweeps Atlantic Coast in asteroid impact...." It was at that point that I wished that I had taken a speed-reading course, because the rest of the headline read: "...scenario for March 16, 2880." I'm really thankful for all those folks who spend countless hours each week with their eyeballs glued to the small end of a telescope as they search the skies, keeping constant vigil for anything heading toward Earth that's larger than a frozen turkey. The men and women of NASA and the Jet Propulsion Lab, college professors and their student assistants and even...

It's the stuff of science fiction movies. Bruce Willis, by a mighty effort, saving the world from extinction by a huge meteor. But Bruce Willis won't do it, and in our current state of readiness, neither will anyone else (sic!). That is why LSU geophysicist Brooks Ellwood is plumbing the geologic record, trying to correlate known mass extinctions to meteor strikes. "When we think about the human race and life in general, what do we worry about? We worry about nuclear holocaust and major glaciation. Then we worry about the giant chunks of rock that fly past Earth all the...

Rock from space might have hit life hard 380 million years ago. 13 June 2003 JOHN WHITFIELD About 380 million years ago, a rock from space smashed into the Earth, say geologists. They believe that the impact wiped out a large fraction of life. The idea could strengthen the controversial connection between mass extinctions and impacts. Up to now, the only candidate for a link is the meteor 65 million years ago that some believe helped exterminate the dinosaurs. Signs of an earlier catastrophe coincide with a disappearance of many animals, says Brooks Ellwood of Louisiana State University, Baton Rouge:...

NEW STUDY: SOME ASTEROIDS MAY BE LAYERED LIKE ONIONS A new study of several meteorites collected on Earth and thought to have come from the same large asteroid reveal the structure of the parent space rock to have been something like an onion, with layer upon layer of differing structure. The asteroid, long ago destroyed in a collision, was once hot enough to have a molten core and cooled from the outside inward, the research shows, confirming a long-held expectation that had eluded supporting research. Asteroids are leftovers of planet formation. While some rocks got together to build planets about...