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The destructive space rock was somewhere between 12.4 and 15.5 miles wide. The largest asteroid ever to hit Earth, which slammed into the planet around 2 billion years ago, may have been even more massive than scientists previously thought. Based on the size of the Vredefort crater, the enormous impact scar left by the gargantuan space rock in what is now South Africa, researchers recently estimated that the epic impactor could have been around twice as wide as the asteroid that wiped out the nonavian dinosaurs. The Vredefort crater, which is located around 75 miles (120 kilometers) southwest of Johannesburg,...

A newly discovered, "potentially hazardous" asteroid almost the size of the world's tallest skyscraper is set to tumble past Earth just in time for Halloween, according to NASA. The asteroid, called 2022 RM4, has an estimated diameter of between 1,083 and 2,428 feet (330 and 740 meters) — just under the height of Dubai's 2,716-foot-tall (828 m) Burj Khalifa, the tallest building in the world. It will zoom past our planet at around 52,500 mph (84,500 km/h), or roughly 68 times the speed of sound. At its closest approach on Nov. 1, the asteroid will come within about 1.43 million...

The space agency estimates there are about 25,000 asteroids of at least 140m in diameter near Earth's orbit. While the odds of them crashing into our planet at any given time are minuscule, Congress directed Nasa to find 90 per cent of them by 2020. Scientists have found fewer than half. But for reasons it has not publicly explained, the administration has proposed delaying by two years, until 2028, the launch of an infrared space telescope meant to find those threatening asteroids and sharply cutting its budget for next year. About 500 times a year, researchers identify asteroids of at...

Explanation: Imaged on July 15 2022, comet C/2017 K2 (PanSTARRS) had a Messier moment, sharing this wide telescopic field of view with globular star cluster Messier 10. Of course M10 was cataloged by 18th century comet hunter Charles Messier as the 10th object on his list of things that were definitely not comets. While M10 is about 14 thousand light-years distant, this comet PanSTARRS was about 15 light-minutes from our fair planet following its July 14 closest approach. Its greenish coma and dust tail entertaining 21st century comet watchers, C/2017 K2 is expected to remain a fine telescopic comet in...

Rather, the comet's behavior is probably typical for comets making their first trip toward the sun — we just haven't been able to observe it before. "What makes this comet special is that it was discovered early," Jewitt said. "We've been able to follow the way the comet changes with distance from the sun over a much larger range than has ever been done before." Comet K2 comes from even farther away than the Kuiper Belt, Jewitt said. The comet's original home was most likely the Oort Cloud, the repository of comets and planetary fragments that extends from 2,000 to...

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,...

Near-Earth Objects Pose Threat, General Says Washington - Sep 17, 2002 This summer, much of the world watched as India and Pakistan faced-off over the disputed Kashmir region, worried that the showdown could escalate into a nuclear war. Coincidentally, U.S. early warning satellites detected an explosion in the Earth's atmosphere June 6, at the height of the tension, with an energy release estimated to be 12 kilotons. Fortunately the detonation, equivalent to the blast that destroyed Hiroshima, occurred over the Mediterranean Sea. However, if it had occurred at the same latitude a few hours earlier, the result on human...

Smaller asteroids may pose greater danger than previously believed INCINERATION POSSIBLE - Fine points of the "fireball" that might be expected from an asteroid exploding in Earth's atmosphere are indicated in a supercomputer simulation devised by a team led by Sandia researcher Mark Boslough. (Photo by Randy Montoya ) Download 300dpi JPEG image (Media are welcome to download/publish this image with related news stories.)ALBUQUERQUE, N.M. — 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 previously published estimates, Sandia National Laboratories supercomputer simulations...

'Asteroid impact could have prompted Constantine's conversion' An asteroid which exploded like a nuclear bomb may have converted the Roman emperor Constantine to Christianity it is now being claimed. Scientists have discovered an impact crater dating from the fourth of fifth century in the Italian Apennine mountains. They believe the crater in the Sirente mountains, which is larger than a football field, could explain the legend of Constantine's conversion. Accounts from the 4th century describe how barbarians stood at the gates of the Roman empire while a Christian movement threatened its stability from within. It is said the emperor saw...

Startling evidence has been found which shows mammoth and other great beasts from the last ice age were blasted with material that came from space.Eight tusks dating to some 35,000 years ago all show signs of having being peppered with meteorite fragments. The ancient remains come from Alaska, but researchers also have a Siberian bison skull with the same pockmarks. The scientists released details of the discovery at a meeting of the American Geophysical Union in San Francisco, US. They painted a picture of a calamitous event over North America that may have severely knocked back the populations of some...

In late June of 1908, a fireball exploded above the remote Russian forests of Tunguska, Siberia, flattening more than 800 square miles of trees. Researchers think a meteor was responsible for the devastation, but neither its fragments nor any impact craters have been discovered. Astronomers have been left to guess whether the object was an asteroid or a comet, and figuring out what it was would allow better modeling of potential future calamities. Italian researchers now think they've found a smoking gun: The 164-foot-deep Lake Cheko, located just 5 miles northwest of the epicenter of destruction. "When we looked at...

By Deborah Zabarenko WASHINGTON (Reuters) - Even small asteroids that never hit Earth could have deadly consequences, because they might be mistaken for nuclear blasts by nations that lack the equipment to tell the difference, scientists said on Thursday. One such asteroid event occurred June 6, when U.S. early warning satellites detected a flash over the Mediterranean that indicated an energy release comparable to the atomic bomb dropped on Hiroshima, U.S. Brig. Gen. Simon Worden told a congressional hearing. The flash occurred when an asteroid perhaps 10 yards in diameter slammed into Earth's atmosphere, producing a shock wave that would...

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...

On the morning of June 30, 1908, the sky exploded over a remote region of central Siberia. A fireball powerful as hundreds of Hiroshima atomic blasts scorched through the upper atmosphere "as if there was a second sun," according to one eyewitness. Scientists today think a small fragment of a comet or asteroid caused the "Tunguska event," so named for the Tunguska river nearby. No one knows for certain, however, because no fragment of the meteoroid has ever been found. The explosion was so vast—flattening and incinerating over an 800 square-mile swath of trees—that generations of amateur sleuths have put...

HOW - 1. "actually you will not be able to see it ... " Spotting ToutatisToutatis will not be visible to the unaided eye. Experienced telescope users can see it now from the Southern Hemisphere, and in early October it will be visible from the north. Finding Toutatis will be challenging, Harris said, due to a combination of the asteroid's position in the sky and interfering moonlight. Because the asteroid is so close, its location in the sky will vary significantly for skywatchers in different places on Earth at any given moment. And because it moves quickly, the location changes...

Rather than look for the light reflected directly by these objects (as is customary astronomy practice), this project will search for those very rare moments when one of these objects passes between the telescopes and a nearby background star. This brief "eclipse" lasts less than a second, but will allow the scientists to study objects that are much too faint to be seen in reflected sunlight, even with the largest telescopes.

Comet C/2017 K2 will be at its closest point to us for the next few million years this week. Hubble caught sight of comet K2 when it was out between the orbits of Saturn and Uranus. NASA, ESA, and A. Feild (STScI) One of the largest comets known is about to zip by our planet on the only trip through the inner solar system it will make during our lifetimes. Five years ago, the Hubble Space Telescope spotted a large comet at the farthest distance ever, as it was approaching the sun from way out between the orbits of Saturn...

In a new study, researchers analyzed some of the tiny fragments of space rock that were left behind after the meteor exploded, known as meteorite dust. Normally, meteors produce a small amount of dust as they burn up, but the tiny grains are lost to scientists because they are either too small to find, scattered by the wind, fall into water or are contaminated by the environment. However, after the Chelyabinsk meteor exploded, a massive plume of dust hung in the atmosphere for more than four days before eventually raining down on Earth's surface, according to NASA. And luckily, layers...

You can see it now, and the view could be getting better in the next two weeks. The comet is called Comet C/2017 K2 and was discovered using the telescope called PanSTARRS. The comet was spotted just five years ago in May 2017... C/2017 K2 is heading toward the sun, and coming closer to Earth. The comet will make its closest approach to Earth on July 14. The comet can now be seen with binoculars in the southern sky after dark. The best viewing is done out in the countryside, away from city lights. NASA adds that C/2017 K2, “is...

Over 100 participants from 18 countries – including NASA scientists and the agency’s NEOWISE mission – took part in the international exercise. Watching the skies for large asteroids that could pose a hazard to the Earth is a global endeavor. So, to test their operational readiness, the international planetary defense community will sometimes use a real asteroid’s close approach as a mock encounter with a “new” potentially hazardous asteroid. The lessons learned could limit, or even prevent, global devastation should the scenario play out for real in the future. To that end, more than 100 astronomers from around the world...