http://www.sciencedaily.com/news/earth_climate/near-earth_object_impacts/ Near-Earth Objects. Near Earth Asteroids. Meteorites have impacted planet Earth many times. Scientists review the geological records and make predictions of risks of near Earth object impacts. en-us Wed, 25 Nov 2009 16:05:01 EST Wed, 25 Nov 2009 16:05:01 EST 60 http://www.sciencedaily.com/images/logosmall.gif http://www.sciencedaily.com/news/earth_climate/near-earth_object_impacts/ For more science articles, visit ScienceDaily. http://www.sciencedaily.com/releases/2009/10/091018141608.htm According to a new study by geologists, the wealth of some minerals that lie in the rock beneath the Earth's surface may be extraterrestrial in origin. Mon, 19 Oct 2009 17:00:00 EDT http://www.sciencedaily.com/releases/2009/10/091018141608.htm http://www.sciencedaily.com/releases/2009/10/091015102246.htm A mysterious basin off the coast of India could be the largest, multi-ringed impact crater the world has ever seen. And if a new study is right, it may have been responsible for killing the dinosaurs off 65 million years ago. Thu, 15 Oct 2009 14:00:00 EDT http://www.sciencedaily.com/releases/2009/10/091015102246.htm http://www.sciencedaily.com/releases/2009/10/091007124411.htm Astronomers in Canada have released footage of a meteor that was approximately 100 times brighter than a full moon. The meteor lit up the skies of southern Ontario two weeks ago and Western astronomers are now hoping to enlist the help of local residents in recovering one or more possible meteorites that may have crashed in the area of Grimsby, Ontario. Thu, 08 Oct 2009 20:00:00 EDT http://www.sciencedaily.com/releases/2009/10/091007124411.htm http://www.sciencedaily.com/releases/2009/09/090917144123.htm Researchers have discovered an unusual kind of meteorite in the Western Australian desert and have uncovered where in the Solar System it came from, in a very rare finding. Sun, 20 Sep 2009 17:00:00 EDT http://www.sciencedaily.com/releases/2009/09/090917144123.htm http://www.sciencedaily.com/releases/2009/08/090806091014.htm NASA's LCROSS spacecraft has successfully completed its first Earth-look calibration of its science payload. During the Earth observations, the spacecraft's spectrometers were able to detect the signatures of the Earth's water, ozone, methane, oxygen, carbon dioxide and possibly vegetation. Mon, 10 Aug 2009 05:00:00 EDT http://www.sciencedaily.com/releases/2009/08/090806091014.htm http://www.sciencedaily.com/releases/2009/07/090731085813.htm A research program aimed at using platinum as an exploration guide for nickel has for the first time been able to put a time scale on the planet's large-scale convection processes. Sat, 01 Aug 2009 11:00:00 EDT http://www.sciencedaily.com/releases/2009/07/090731085813.htm http://www.sciencedaily.com/releases/2009/06/090601085930.htm Large bombardments of meteoroids approximately four billion years ago could have helped to make the early Earth and Mars more habitable for life by modifying their atmospheres, suggests a new article. Mon, 01 Jun 2009 14:00:00 EDT http://www.sciencedaily.com/releases/2009/06/090601085930.htm http://www.sciencedaily.com/releases/2009/05/090522081425.htm Scientists have studied the El'gygytgyn meteorite impact crater in Arctic Siberia. They found, from analyses of the drill cores, new information about the formation of the impact crater, as well as information they can use more fully to understand the climate history of the Arctic. Tue, 26 May 2009 08:00:00 EDT http://www.sciencedaily.com/releases/2009/05/090522081425.htm http://www.sciencedaily.com/releases/2009/05/090520140403.htm The bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas would not have had the firepower to extinguish potential early life on the planet and may even have given it a boost, according to a new study. Wed, 20 May 2009 17:00:00 EDT http://www.sciencedaily.com/releases/2009/05/090520140403.htm http://www.sciencedaily.com/releases/2009/05/090505072948.htm Nearly all meteorite impact craters on Earth are circular. Elongated crater structures are expected only at impacts at angles lower than 12 degrees from the horizontal. Geologists document the first elliptical crater on Earth that provides insights into the mechanisms of crater formation at low angles. Fri, 08 May 2009 23:00:00 EDT http://www.sciencedaily.com/releases/2009/05/090505072948.htm http://www.sciencedaily.com/releases/2009/04/090429091637.htm A geologist and tsunami expert debunks persistent idea that so-called "chevrons," large U- or V-shaped formations found in some of the world's coastal areas, are evidence of megatsunamis caused by asteroids or comets slamming into the ocean. Thu, 30 Apr 2009 17:00:00 EDT http://www.sciencedaily.com/releases/2009/04/090429091637.htm http://www.sciencedaily.com/releases/2009/04/090427010803.htm The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a new article. A impact didn't lead to mass extinction 65 million years ago, geologists find. Tue, 28 Apr 2009 11:00:00 EDT http://www.sciencedaily.com/releases/2009/04/090427010803.htm http://www.sciencedaily.com/releases/2009/04/090409104134.htm Thirty-four-million years ago, Earth changed profoundly. What happened, and how were Earth's animals, plants, oceans, and climate affected? Focusing on the end of the Eocene epoch and the Eocene-Oligocene transition was a critical but very brief interval in Earth's history. Thu, 09 Apr 2009 23:00:00 EDT http://www.sciencedaily.com/releases/2009/04/090409104134.htm http://www.sciencedaily.com/releases/2009/03/090317153047.htm NASA scientists analyzing the dust of meteorites have discovered new clues to a long-standing mystery about how life works on its most basic, molecular level. Wed, 18 Mar 2009 20:00:00 EDT http://www.sciencedaily.com/releases/2009/03/090317153047.htm http://www.sciencedaily.com/releases/2009/01/090107134526.htm Asteroids are hunks of rock that orbit in the outer reaches of space, and scientists have generally assumed that their small size limited the types of rock that could form in their crusts. But two newly discovered meteorites may rewrite the book on how some asteroids form and evolve. Thu, 08 Jan 2009 23:00:00 EST http://www.sciencedaily.com/releases/2009/01/090107134526.htm http://www.sciencedaily.com/releases/2009/01/090107085320.htm Scientists have discovered only the second example of a meteorite impact that occurred at the same time as massive volcanic activity. The first time such a coincidence was observed, at the Cretaceous-Tertiary boundary, was the catastrophic event thought to be responsible for the extinction of the dinosaurs, 65 million years ago. Wed, 07 Jan 2009 20:00:00 EST http://www.sciencedaily.com/releases/2009/01/090107085320.htm http://www.sciencedaily.com/releases/2008/11/081128082939.htm The remains of a 10-tonne asteroid that exploded in the sky near the Alberta/Saskatchewan border on November 20, 2008 have been located in a rural area near the city of Lloydminster. Tue, 02 Dec 2008 02:00:00 EST http://www.sciencedaily.com/releases/2008/11/081128082939.htm http://www.sciencedaily.com/releases/2008/11/081126091541.htm Based on the amount and frequency of meteorite falls and the formation of impact craters on the Earth, there should be over 20 impact craters in the <100 m size range that formed within the past 10,000 years, yet only five such craters are known worldwide. Mon, 01 Dec 2008 11:00:00 EST http://www.sciencedaily.com/releases/2008/11/081126091541.htm http://www.sciencedaily.com/releases/2008/11/081125141600.htm Researchers have found a tool that could reveal possibly hundreds of undiscovered craters across Canada and around the world. As more craters are found and analyzed existing theories on how many meteorites have hit Earth in the past and the frequency of future impacts will change. Tue, 25 Nov 2008 00:00:00 EST http://www.sciencedaily.com/releases/2008/11/081125141600.htm http://www.sciencedaily.com/releases/2008/09/080922100455.htm Some of the world's rarest and most precious metals, including platinum and iridium, could owe their presence in the Earth's crust to iron and stony-iron meteorites, fragments of a large number of asteroids that underwent significant geological processing in the early Solar System. Sat, 04 Oct 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/09/080922100455.htm http://www.sciencedaily.com/releases/2008/08/080828171703.htm Eroded gullies on the flanks of Martian craters may have been formed by snowmelt as recently as a few hundred thousand years ago and in sites once occupied by glaciers. Similar conditions can be found in Antarctica's McMurdo Dry Valleys. Rather than being a dead planet, the new data are consistent with dynamic climate changes on Mars. Sat, 30 Aug 2008 08:00:00 EDT http://www.sciencedaily.com/releases/2008/08/080828171703.htm http://www.sciencedaily.com/releases/2008/07/080701105330.htm The year is 1908, and it's just after seven in the morning. A man is sitting on the front porch of a trading post at Vanavara in Siberia. Little does he know, in a few moments, he will be hurled from his chair and the heat will be so intense he will feel as though his shirt is on fire. That's how the Tunguska event felt 40 miles from ground zero. Tue, 01 Jul 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/07/080701105330.htm http://www.sciencedaily.com/releases/2008/06/080619102553.htm The movements in the liquid part of the Earth's core are changing surprisingly quickly, and this affects the Earth's magnetic field, according to new research. Fri, 20 Jun 2008 17:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080619102553.htm http://www.sciencedaily.com/releases/2008/06/080619142106.htm Hikers visiting the Kilauea Iki crater in Hawaii today walk along a mostly flat surface of sparsely vegetated basalt. It looks like parking lot asphalt, but in November and December 1959, it emitted the orange glow of newly erupted lava. Now, a precision analysis of lava samples taken from the crater is giving scientists a new tool for reconstructing planetary origins. Thu, 19 Jun 2008 17:00:00 EDT http://www.sciencedaily.com/releases/2008/06/080619142106.htm http://www.sciencedaily.com/releases/2008/05/080505120702.htm The asteroid presumed to have wiped out the dinosaurs struck the Earth with such force that carbon deep in the Earth's crust liquefied, rocketed skyward, and formed tiny airborne beads that blanketed the planet, say scientists from the US, UK, Italy, and New Zealand in this month's Geology. Mon, 05 May 2008 17:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080505120702.htm http://www.sciencedaily.com/releases/2008/05/080501093513.htm Geologists call into question three decades of conventional wisdom regarding some of the physical processes that helped shape the Earth as we know it today. New research provides a direct challenge to the popular "late veneer hypothesis," a theory which suggests that all of our water, as well as several so-called "iron-loving" elements, were added to the Earth late in its formation by impacts with icy comets, meteorites and other passing objects. Sat, 03 May 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080501093513.htm http://www.sciencedaily.com/releases/2008/05/080502092145.htm A new study suggests the solar system passes through the plane of the galaxy every 35 to 40 million years. The period coincides with evidence of crater impact and mass extinctions on Earth. The paper suggests gravitational forces from gas and dust clouds in the galactic plane send comets into the inner solar system and into the path of the Earth. The periods of comet bombardment also coincide with mass extinctions, such as that of the dinosaurs 65 million years ago. Our present position in the galaxy suggests we are now very close to another such period. Fri, 02 May 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/05/080502092145.htm http://www.sciencedaily.com/releases/2008/04/080428081732.htm Chondritic meteorites have a similar chemical composition to the sun and are therefore reliable witnesses as to what the solar nebula, from which the planets formed, was composed of. This can be used to deduce what the Earth consists of chemically. However, researchers have now discovered that strictly speaking this fundamental geological assumption is not true. Tue, 29 Apr 2008 20:00:00 EDT http://www.sciencedaily.com/releases/2008/04/080428081732.htm http://www.sciencedaily.com/releases/2008/03/080327171053.htm Explosive eruptions and noxious gas emissions at Kilauea Volcano in Hawaii this week have prompted scientists to work around the clock to understand what will happen next. Scientists are monitoring gas emissions and seismic activity at Kilauea, which on March 19 experienced its first explosive eruption since 1924. The volcano is also emitting sulfur dioxide at toxic levels. Sat, 29 Mar 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080327171053.htm http://www.sciencedaily.com/releases/2008/03/080314110406.htm Meteorite impacts are often associated with huge disasters, mass extinction and why the dinosaurs disappeared from the face of the Earth some 65 million years ago. However, the opposite may also occur -- that new and more varied animal life arises following such a catastrophe, is shown by new research. In prehistoric times, the Earth was hit by a hailstorm of meteorites with a belt of dust that subsequently covered the planet. At this time new and more varied animal life arose. Fri, 14 Mar 2008 14:00:00 EDT http://www.sciencedaily.com/releases/2008/03/080314110406.htm http://www.sciencedaily.com/releases/2008/01/080123125543.htm The most detailed 3-D seismic images yet of the Chicxulub impact crater may modify a theory explaining the "KT Extinction Event" that wiped out most life on Earth, including the dinosaurs. According to new research the asteroid landed in deeper water than previously assumed and therefore released about 6.5 times more water vapor into the atmosphere, possibly making it deadlier by altering climate and generating acid rain. Thu, 24 Jan 2008 11:00:00 EST http://www.sciencedaily.com/releases/2008/01/080123125543.htm http://www.sciencedaily.com/releases/2007/12/071218122415.htm The stunning amount of forest devastation at Tunguska a century ago in Siberia may have been caused by an asteroid only a fraction as large as those postulated in previously published estimates, Sandia supercomputer simulations suggest. Because there are more smaller asteroids than larger ones, the need to guard against such impacts may be greater than previously thought. Wed, 19 Dec 2007 23:00:00 EST http://www.sciencedaily.com/releases/2007/12/071218122415.htm http://www.sciencedaily.com/releases/2007/12/071205131152.htm Observations about the early formation of Earth may answer an age-old question about why the planet's mantle is missing some of the matter that should be present. Earth is made from chondrite, very primitive rocks of meteorites that date from the earliest time of the solar system before the Earth was formed. However, scientists have been puzzled why the composition of Earth's mantle and core differed from that of chondrite. Sun, 09 Dec 2007 14:00:00 EST http://www.sciencedaily.com/releases/2007/12/071205131152.htm http://www.sciencedaily.com/releases/2007/11/071113085735.htm The Japan Aerospace Exploration Agency (JAXA) and NHK (Japan Broadcasting Corporation) have successfully performed the world's first high-definition image taking of an Earth-rise by the lunar explorer "KAGUYA" (SELENE), which was injected into a lunar orbit at an altitude of about 100 km on October 18, 2007. Wed, 14 Nov 2007 02:00:00 EST http://www.sciencedaily.com/releases/2007/11/071113085735.htm http://www.sciencedaily.com/releases/2007/10/071021143653.htm In research that could aid decisions about future asteroids on a collision course with Earth, scientists have for the first time determined the composition of a near-Earth asteroid that has a very slight possibility of someday hitting our planet. That information could be useful in planning any future space mission to explore the asteroid, called Apophis. And if the time ever were to come when this object or another turned out to be on its way toward an impact on Earth, knowing what it's made of could be one important factor in deciding what to do about it. Mon, 22 Oct 2007 02:00:00 EDT http://www.sciencedaily.com/releases/2007/10/071021143653.htm http://www.sciencedaily.com/releases/2007/07/070713131217.htm Volcanologist Sarah Fagents from the School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa had an amazing opportunity to study volcanic hazards first hand, when a volcanic mudflow broke through the banks of a volcanic lake at Mount Ruapehu in New Zealand. Mon, 16 Jul 2007 20:00:00 EDT http://www.sciencedaily.com/releases/2007/07/070713131217.htm http://www.sciencedaily.com/releases/2007/07/070706115006.htm Researchers have developed a software package for modelling asteroid impacts that enables them to assess the potential human and economic consequences across the globe. Early results indicate that the ten countries most at risk are China, Indonesia, India, Japan, the United States, the Philippines, Italy, the United Kingdom, Brazil and Nigeria. Mon, 09 Jul 2007 17:00:00 EDT http://www.sciencedaily.com/releases/2007/07/070706115006.htm http://www.sciencedaily.com/releases/2007/06/070628162400.htm Research comparing silicon samples from Earth, meteorites and planetary materials, published in Nature (June 28, 2007) provides new evidence that the Earth's core formed under very different conditions from those that existed on Mars. It also shows that the Earth and the moon have the same silicon isotopic composition, supporting the theory that atoms from the two mixed in the early stages of their development. Tue, 03 Jul 2007 14:00:00 EDT http://www.sciencedaily.com/releases/2007/06/070628162400.htm http://www.sciencedaily.com/releases/2007/04/070418141027.htm A fender-bender between two celestial bodies that left a 200 mile-wide metallic chunk to cool in space was the likely source of a group of meteorites known as the IVA iron meteorites, suggests new research by University of Massachusetts Amherst scientists. Their findings help explain conflicting meteorite data that has long puzzled scientists, and sheds new light on how and when asteroids form. Thu, 19 Apr 2007 11:00:00 EDT http://www.sciencedaily.com/releases/2007/04/070418141027.htm http://www.sciencedaily.com/releases/2007/01/070118094039.htm About 65 million years ago, a massive disruption led to worldwide extinction of dinosaurs. The impact of a giant asteroid created massive tsunamis and spewed forth a global cloud of carbon gases that altered Earth's atmosphere and blocked the light for weeks, possibly years. In recent years, that impact event has been linked to a 112-mile-wide crater, dubbed Chicxulub, on the coast of Mexico's Yucatan Peninsula. Mon, 22 Jan 2007 05:00:00 EST http://www.sciencedaily.com/releases/2007/01/070118094039.htm http://www.sciencedaily.com/releases/2006/12/061223092706.htm Scientists at the Naval Research Laboratory have analyzed samples from Comet Wild 2, as part of NASA's Stardust mission, the first solid sample return mission since Apollo. Over 100 scientists at various institutions participated in the preliminary analysis. NRL contributed to the Mineralogy and Petrology, Crater, Bulk Chemistry and Isotope analysis teams by studying the structure and composition of the comet samples using transmission electron microscopy (TEM). Sun, 24 Dec 2006 11:00:00 EST http://www.sciencedaily.com/releases/2006/12/061223092706.htm http://www.sciencedaily.com/releases/2006/12/061204195843.htm NASA researchers at Johnson Space Center, Houston have found organic materials that formed in the most distant reaches of the early Solar System preserved in a unique meteorite. The study was performed on the Tagish Lake carbonaceous chondrite, a rare type of meteorite that is rich in organic (carbon-bearing) compounds. Tue, 05 Dec 2006 11:00:00 EST http://www.sciencedaily.com/releases/2006/12/061204195843.htm http://www.sciencedaily.com/releases/2006/10/061023192530.htm There's growing evidence that the dinosaurs and most their contemporaries were not wiped out by the famed Chicxulub meteor impact, according to a paleontologist who says multiple meteor impacts, massive volcanism in India and climate changes culminated in the end of the Cretaceous Period. Tue, 24 Oct 2006 02:00:00 EDT http://www.sciencedaily.com/releases/2006/10/061023192530.htm http://www.sciencedaily.com/releases/2006/10/061021115722.htm The Permian-Triassic extinction is the largest recorded, more disastrous for life forms than the extinction that killed the dinosaurs. Its cause continues to be debated. USC earth scientists say their latest research points to gradual deterioration in the environment due in part to ocean warming. Sat, 21 Oct 2006 08:00:00 EDT http://www.sciencedaily.com/releases/2006/10/061021115722.htm http://www.sciencedaily.com/releases/2006/09/060926104410.htm Ilya Usoskin (Sodankylä Geophysical Observatory, University of Oulu, Finland) and his colleagues have investigated the solar activity over the past centuries. Their study is to be published this week in Astronomy & Astrophysics Letters. They compare the amount of Titanium 44 in 19 meteorites that have fallen to the Earth over the past 240 years. Their work confirms that the solar activity has increased strongly during the 20th century. They also find that the Sun has been particularly active in the past few decades. Wed, 27 Sep 2006 17:00:00 EDT http://www.sciencedaily.com/releases/2006/09/060926104410.htm http://www.sciencedaily.com/releases/2006/09/060914181246.htm Although last year's inclement weather resulted in fewer Antarctic meteorite recoveries than usual, scientists have recently discovered that one of the specimens is a rare breed -- a type of lunar meteorite seen only once before. Fri, 15 Sep 2006 11:00:00 EDT http://www.sciencedaily.com/releases/2006/09/060914181246.htm http://www.sciencedaily.com/releases/2006/06/060601174729.htm Planetary scientists have found evidence of a meteor impact much larger and earlier than the one that killed the dinosaurs -- an impact that they believe caused the biggest mass extinction in Earth's history. The 300-mile-wide crater lies hidden more than a mile beneath the East Antarctic Ice Sheet. And the gravity measurements that reveal its existence suggest that it could date back about 250 million years -- the time of the Permian-Triassic extinction, when almost all animal life on Earth died out. Thu, 01 Jun 2006 08:00:00 EDT http://www.sciencedaily.com/releases/2006/06/060601174729.htm http://www.sciencedaily.com/releases/2006/04/060421234604.htm The depths of space are much closer to home following the University of Alberta's acquisition of a meteorite that is the only one of its kind known to exist on Earth! Fri, 21 Apr 2006 11:00:00 EDT http://www.sciencedaily.com/releases/2006/04/060421234604.htm