Free Republic

When UC Santa Barbara geology professor emeritus James Kennett and colleagues set out years ago to examine signs of a major cosmic impact that occurred toward the end of the Pleistocene epoch, little did they know just how far-reaching the projected climatic effect would be... the Younger Dryas Impact Hypothesis, which postulates that a fragmented comet slammed into the Earth close to 12,800 years ago, causing rapid climatic changes, megafaunal extinctions, sudden human population decrease and cultural shifts and widespread wildfires (biomass burning)... suggests a possible triggering mechanism for the abrupt changes in climate at that time, in particular a...

Scientists from NASA and the Planetary Science Institute in Tucson, Ariz., have identified what could be a supervolcano on Mars—the first discovery of its kind. The volcano in question, a vast circular basin on the face of the Red Planet, previously had been classified as an impact crater. Researchers now suggest the basin is actually what remains of an ancient supervolcano eruption. Their assessment is based on images and topographic data from NASA's Mars Odyssey, Mars Global Surveyor and Mars Reconnaissance Orbiter spacecraft, as well as the European Space Agency's Mars Express orbiter.In the Oct. 3 issue of the journal...

It's well known that the dinosaurs were wiped out 66 million years ago when a meteor hit what is now southern Mexico but evidence is accumulating that the biggest extinction of all, 252.3m years ago, at the end of the Permian period, was also triggered by an impact that changed the climate. While the idea that an impact caused the Permian extinction has been around for a while, what's been missing is a suitable crater to confirm it. Associate Professor Eric Tohver of the University of Western Australia's School of Earth and Environment believes he has found the impact crater...

Portuguese scientists have found a depression on the Atlantic Ocean floor they think may be an impact crater. The roughly circular, 6km-wide hollow has a broad central dome and has been dubbed the "Fried Egg" because of its distinctive shape. It was detected to the south of the Azores Islands during a survey to map the continental shelf. If the Fried Egg was made by a space impactor, the collision probably took place within the past 17 million years... It lies under 2km of water about 150km from the Azores archipelago. The depressed ring sits roughly 110m below the...

On June 19, maritime treasure hunters -- who were looking for priceless submerged hooch in shipwrecks -- discovered a 60-meter-diameter circle 87 meters under the Baltic Sea. Are these the remains of an alien vessel or Cthulhu's personal pan pizza? Next to the circle is a 300 meter long slide track -- as if the circle has traveled across the seabed before it has settled [...] They rule out theories that there is a depth bomb or mine from the First World War -- or a symmetrical [algal] bloom [...] The most likely scenario is still that there is a...

Largest ever field of impact craters uncovered 10:00 07 November 04 The discovery of the largest field of impact craters ever uncovered on Earth is the first evidence that the planet suffered simultaneous meteor impacts in the recent past. The field has gone unnoticed until now because it is partially buried beneath the sands of the Sahara desert in south-west Egypt. Philippe Paillou of Bordeaux University Observatory in Floirac, France, first noticed circular geological structures in the Sahara last year, while analysing radar satellite pictures of the area. The structures turned out to be part of a huge field of...