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More than 3.8 billion years ago, in a time period called the Hadean eon, our planet Earth was constantly bombarded by asteroids, which caused the large-scale melting of its surface rocks. Most of these surface rocks were basalts, and the asteroid impacts produced large pools of superheated impact melt of such composition. These basaltic pools were tens of kilometres thick, and thousands of kilometres in diameter. “If you want to get an idea of what the surface of Earth looked like at that time, you can just look at the surface of the Moon which is covered by a vast...

GRAND MARAIS, Minn. - A forest fire has led to a chance discovery of debris from the impact of a meteorite 1.85 billion years ago, more than 450 miles away at Sudbury, Ontario. Geologists had scheduled a field trip in May along the Gunflint Trail in northeastern Minnesota, but most areas they wanted to explore were closed because of a wildfire that charred more than 118 square miles. Geologist Mark Jirsa of the Minnesota Geological Survey went up the trail to scout new locations and, in a spot he had never visited before, stumbled across debris now linked to the...

Heavenly bodies stir up routine catastrophes March 18 2003 at 01:30PM By Graeme Addison Legend has it that when two people get together and er... bond, the Earth will move – at least in a metaphorical sense. Likewise, it takes two heavenly bodies, an impactor and a target, to come together with Earth-shattering force to form a crater. There’s nothing dreamlike about this: it happens, frequently, throughout the solar system. Impact catastrophes are routine. Just over two-billion years ago, a chunk of asteroid at least the size of Table Mountain struck the landmass that is now South Africa. It hurtled...

"Through field studies, we determined that Chicxulub has about 18,000 cubic kilometers of impact melt, approximately four times the volume of water in Lake Michigan," Pope said. "Sudbury has about 31,000 cubic kilometers of impact melt, approximately six times the volume of lakes Huron and Ontario combined, and nearly 70 percent more than the melt at Chicxulub." ...The researchers then used an analytical cratering model to examine possible causes for the huge difference in melt. According to the simulation results, the difference in melt volume could be readily explained if Chicxulub -- the impact crater that doomed the dinosaurs --...

Whilst discussing the merits of the newly-proposed Bush space plan on another site, this subject came up. Is it: a. an asteroid impact site? b. one of the largest nickel mines in the world? c. formerly one of the largest sources of sulfur dioxide in North America? d. an indication of where our resources in space exploration really should be going? or e. all of the above? For me, the answer is (e). Aerial radar image of the Sudbury complex, Ontario, Canada.