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Here, for the first time (to our knowledge), we are able to demonstrate unambiguously that the impact at the Cretaceous–Paleogene boundary (K–Pg, ∼66 Mya) was followed by a so-called “impact winter.” This impact winter was the result of the injection of large amounts of dust and aerosols into the stratosphere and significantly reduced incoming solar radiation for decades. Therefore, this phase will have been a key contributory element in the extinctions of many biological clades, including the dinosaurs. The K–Pg boundary impact presents a unique event in Earth history because it caused global change at an unparalleled rate. This detailed...

Astronomers initially thought the object was an asteroid when they spotted it in early October, and named it Asteroid 2015 TB145. But using the US space agency's Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, experts "have determined that the celestial object is more than likely a dead comet that has shed its volatiles after numerous passes around the sun," NASA's Jet Propulsion Laboratory said in a statement late Friday. ... The space rock has already grabbed attention with its unusually high speed and big size, about as large as a football stadium at 2,000 feet (600 meters) in diameter....

Using a new process in planetary formation modeling, where planets grow from tiny bodies called "pebbles," Southwest Research Institute scientists can explain why Mars is so much smaller than Earth. This same process also explains the rapid formation of the gas giants Jupiter and Saturn, as reported earlier this year. "This numerical simulation actually reproduces the structure of the inner solar system, with Earth, Venus, and a smaller Mars," said Hal Levison, an Institute scientist at the SwRI Planetary Science Directorate. He is the first author of a new paper published in the Proceedings of the National Academy of Sciences...

Elizabeth Palermo September 15, 2015An artist's depiction of the dual meteor strike. (Don Dixon/Erik Sturkell/University of Gothenburg) It's not altogether uncommon to hear about double rainbows, but what about a double meteor strike? It's a rare event, but researchers in Sweden recently found evidence that two meteors smacked into Earth at the same time, about 458 million years ago. Researchers from the University of Gothenburg uncovered two craters in the county of Jämtland in central Sweden. The meteors that formed the craters landed just a few miles from each other at the same moment, according to Erik Sturkell, a professor...

A big asteroid sailed past Earth last month, and astronomers haven't yet totally excluded the possibility that it'll hit us when it comes around in 2032. If the past is any guide, we won't have to worry about asteroid 2013 TV135 — but it's a reminder that we'll have to fend off a killer space rock one of these days. Ukrainian astronomers discovered 2013 TV135 just 10 days ago, well after the asteroid had its close encounter with Earth on Sept. 16. Actually, it wasn't all that close: The distance was 4.2 million miles (6.7 million kilometers), or about 17...

On Monday, Jupiter took a massive hit from a meteor, which was spotted by amateur astronomers based in the US—and if previous evidence is anything to go by, it could have saved Earth from a massive collision in the process. Dan Peterson of Racine, Wisconsin, was gazing at Jupiter on Monday when he saw a bright, white flash on the surface of the planet. When he posted his observation online, another astrophotographer, George Hall, discovered he'd unknowingly captured the massive explosion on video. Turns out it was probably a meteor striking the surface of the planet—and you can watch the...

Without warning, a mystery object struck Jupiter on July 19, 2009, leaving a dark bruise the size of the Pacific Ocean. The spot first caught the eye of an amateur astronomer in Australia, and soon, observatories around the world, including NASA’s Hubble Space Telescope, were zeroing in on the unexpected blemish. Astronomers had witnessed this kind of cosmic event before. Similar scars had been left behind during the course of a week in July 1994, when more than 20 pieces of Comet P/Shoemaker-Levy 9 (SL9) plunged into Jupiter’s atmosphere. The 2009 impact occurred during the same week, 15 years later....

In breaking news, Anthony Wesley reports another impact on Jupiter, this morning. In his words: ".. at approximately 20:30utc this morning I recorded a large fireball on Jupiter, it lasted a couple of seconds and was very bright.This was a large fireball, but it doesn't seem to have left any mark, probably all gone in the upper atmosphere before it reached the clouds."His preliminary image (a raw frame from the video) is shown below. The fireball can be seen in the upper left of frame. A video and more details will follow soon.Stay tuned to IceInSpace for more, and for...

Amateur sightings prompt call for a network of backyard astronomers.On August 20, for the third time in about a year, amateur astronomers spotted a fireball above Jupiter's atmosphere. The discovery suggests the planet gets walloped more often than previously thought, say astronomers, some of whom are calling for a global "volunteer army" of backyard Jupiter watchers. The recent flash follows on the heels of July 2009 and June 2010 fireballs over the gas giant planet. (See "Bright Fireball Slams Into Jupiter" [June 2010] and "Jupiter Impact Creates Huge New Spot" [July 2009].) Astronomers speculate that the August 20 flash was...

Stephen Hawking believes that one of the major factors in the possible scarcity of intelligent life in our galaxy is the high probability of an asteroid or comet colliding with inhabited planets. We have observed, Hawking points out in Life in the Universe, the collision of a comet, Schumacher-Levi, with Jupiter (below), which produced a series of enormous fireballs, plumes many thousands of kilometers high, hot "bubbles" of gas in the atmosphere, and large dark "scars" on the atmosphere which had lifetimes on the order of weeks. It is thought the collision of a rather smaller body with the Earth,...

Hubble has trained its new camera on the atmospheric disturbance on Jupiter believed to have been caused by a comet or asteroid impact. The telescope used the Wide Field Camera 3 fitted on the recent shuttle servicing mission to capture ultra-sharp visible-light images of the scar. The dark spot near the gas giant's southern pole was noticed first by an amateur Australian astronomer.

PASADENA, California — A large comet or asteroid has slammed into Jupiter, creating an impact site the size of Earth, pictures by an Australian amateur astronomer show. NASA's Jet Propulsion Laboratory confirmed the discovery using its large infrared telescope at the summit of Mauna Kea in Hawaii, said computer programer Anthony Wesley, 44, who discovered the impact zone while stargazing at home. News of Wesley's find on a backyard 14.5-inch reflecting telescope has stunned the astronomy world, with scientists saying the impact will last only days more. Wesley said it took him 30 minutes to realize a dark spot rotating...

Without Jupiter acting as a "cosmic vacuum cleaner" sucking up these dangerous objects, there would be so many catastrophic impacts that life probably wouldn't have evolved on the Earth and we wouldn't be here today... "This vacuum cleaner idea goes back to when the long-period comets coming in from the Oort Cloud were viewed as being the only significant impact risk," says Horner. "In the 1950s there were only one or two near-Earth asteroids known, so they were viewed as oddities." ...Since the 1950s, scientists have discovered more objects in the solar system, and they say many of them could...

Jupiter increases risk of comet strike on Earth 11:53 24 August 2007 NewScientist.com news service David Shiga Earth experienced an especially heavy bombardment of asteroids and comets early in the solar system's history (Illustration: Julian Baum) Contrary to prevailing wisdom, Jupiter does not protect Earth from comet strikes. In fact, Earth would suffer fewer impacts without the influence of Jupiter's gravity, a new study says. It could have implications for determining which solar systems are most hospitable to life. A 1994 study showed that replacing Jupiter with a much smaller planet like Uranus or Neptune would lead to 1000 times...

A mini asteroid collided safely with Sudan this week, but mega disaster looms with nearly 1000 hazardous near-Earth objects roaming our universe—plus even more dangerous ones we haven't spotted yet. With no response plan for the worst-case scenario in place anywhere on Earth, four-time shuttle astronaut Thomas D. Jones offers a call to arms against the coming cosmic storm. Early last Monday, Richard Kowalski, a University of Arizona astronomer at the Catalina Sky Survey team's 60-in. search telescope atop Mt. Lemmon near Tucson, flashed word to NASA of the discovery of a new Near Earth Object (NEO). The small asteroid,...

Just before dawn on Oct. 7, 2008, an SUV-sized asteroid entered Earth's atmosphere and exploded harmlessly over the Nubian Desert of northern Sudan. Scientists expected the asteroid, called 2008 TC3, had blown to dust in the resulting high-altitude fireball. What happened next excited the scientific community. Peter Jenniskens, a meteor astronomer with the SETI Institute in Mountain View, Calif., who works at NASA's Ames Research Center in Moffett Field, Calif., joined Muawia Shaddad of the University of Khartoum in Sudan to search for possible extraterrestrial remnants from the asteroid. A paper, featured as the cover story in the March 26...

When an asteroid was spotted heading towards our planet last October, researchers rushed to document a cosmic impact from start to finish for the first time. Roberta Kwok tells the tale.Around midnight on 6 October 2008, a white dot flitted across the screen of Richard Kowalski's computer at an observatory atop Mount Lemmon in Arizona. Kowalski had seen hundreds of such dots during three and a half years of scanning telescope images for asteroids that might hit Earth or come close. He followed the object through the night and submitted the coordinates, as usual, to the Minor Planet Center in...

STRANGE ASTEROID: Newly-discovered asteroid 2009 BD is slowly passing by Earth today only 400,000 miles away. The small 10m-wide space rock poses no threat, but it merits attention anyway. The orbit of 2009 BD appears to be almost identical to the orbit of Earth. 2009 BD may be a rare co-orbital asteroid, circling the sun in near-tandem with our planet. Extrapolating the motion of 2009 BD into the future, we see that it remains in the vicinity of Earth for many months to come, never receding farther than 0.1 AU (9.3 million miles) until Nov. 2010. Future observations may reveal...

A space rock a few metres across exploded over northern Sudan early in the morning of Tuesday 7 October. The small asteroid mostly disintegrated when it collided with Earth's atmosphere, but fragments may have reached the surface. Such an event happens roughly every three months. But this is "the first time we were able to discover and predict an impact before the event", says Donald Yeomans, manager of NASA's Near-Earth Object (NEO) programme at the Jet Propulsion Laboratory (JPL) in Pasadena, California. Incoming! The story began on Sunday evening, when astronomers with the Catalina Sky Survey near Tucson, Arizona, discovered...

WASHINGTON – Astronomers say a small asteroid is about to make a fiery but harmless dive into Earth's atmosphere early Tuesday morning over Africa. Harvard scientists announced late Monday afternoon that the unnamed asteroid will burn up in the sky, making a fireball that people in northern Africa should be able to see. The rock is between 3 feet and 15 feet in diameter. It's expected to enter Earth's atmosphere above Sudan at 10:46 p.m. EDT Monday, which is just before dawn in Africa.