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Keyword: comets

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  • NEOWISE Spots a “Weirdo” Comet

    04/10/2014 1:07:22 PM PDT · by SunkenCiv · 17 replies
    Universe Today ^ | February 28, 2014 | Jason Major
    NASA’s NEOWISE mission — formerly known as just WISE — has identified the first comet of its new near-Earth object hunting career… and, according to mission scientists, it’s a “weirdo.” To date several new asteroids have already been found by NEOWISE, and on February 14, 2014, it spotted its first comet. “We are so pleased to have discovered this frozen visitor from the outermost reaches of our solar system,” said Amy Mainzer, NEOWISE principal investigator at JPL. “This comet is a weirdo — it is in a retrograde orbit, meaning that it orbits the sun in the opposite sense from...
  • 'Cosmos' Recap: Halley's Comet History and 4 More Amazing Facts from Episode 3

    03/24/2014 9:36:36 PM PDT · by EveningStar · 12 replies
    Space.com ^ | March 24, 2014 | Miriam Kramer
    The newest episode of "Cosmos: A Spacetime Odyssey" dove into all things big and small including the history of modern science. Aired Sunday night (March 23), the third episode of the reboot of Carl Sagan's beloved TV show "Cosmos: A Personal Voyage" explains how knowledge of the workings of gravity, comets and the solar system changed the way that humans look at the stars and science.
  • Astronomy Picture of the Day -- Sungrazer

    10/27/2013 9:05:20 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 27, 2013 | (see photo credit)
    Explanation: Arcing toward a fiery fate, this Sungrazer comet was recorded by the SOHO spacecraft's Large Angle Spectrometric COronagraph(LASCO) on December 23, 1996. LASCO uses an occulting disk, partially visible at the lower right, to block out the otherwise overwhelming solar disk allowing it to image the inner 8 million kilometers of the relatively faint corona. The comet is seen as its coma enters the bright equatorial solar wind region (oriented vertically). Positioned in space to continuously observe the Sun, SOHO has now been used to discover over 1,500 comets, including numerous sungrazers. Based on their orbits, the vast majority...
  • Comet's water 'like that of Earth's oceans'

    10/05/2011 6:41:44 PM PDT · by decimon · 39 replies
    BBC ^ | October 5, 2011 | Jason Palmer
    Comet Hartley 2 contains water more like that found on Earth than prior comets seem to have, researchers say. A study using the Herschel space telescope aimed to measure the quantity of deuterium, a rare type of hydrogen, present in the comet's water. The comet had just half the amount of deuterium seen in comets. The result, published in Nature, hints at the idea that much of the Earth's water could have initially came from cometary impacts. Just a few million years after its formation, the early Earth was rocky and dry; something must have brought the water that covers...
  • Small Comets and Our Origins

    10/19/2004 11:13:25 PM PDT · by SunkenCiv · 80 replies · 1,857+ views
    University of Iowa ^ | circa 1999 | Louis A. Frank
    Given the reality of the dark spots, which soon became known as "atmospheric holes" because of their appearance in the images, there is only one explanation which has endured over all these years to present. That is, the holes are due to the shadowing of the atmospheric light by an object above the atmosphere. This object simply cannot be a stony or iron meteor because the holes are very large, tens of miles in diameter. A rock of this size would provide a disastrous impact on the Earth's surface. As it turns out, water vapor is very good at absorbing...
  • Did Comets Contain Key Ingredients For Life On Earth?

    06/06/2009 10:52:58 AM PDT · by SunkenCiv · 51 replies · 817+ views
    ScienceDaily ^ | April 29, 2009 | Adapted from materials provided by Tel Aviv University
    While investigating the chemical make-up of comets, Prof. Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv University found they were the source of missing ingredients needed for life in Earth's ancient primordial soup. "When comets slammed into the Earth through the atmosphere about four billion years ago, they delivered a payload of organic materials to the young Earth, adding materials that combined with Earth's own large reservoir of organics and led to the emergence of life," says Prof. Bar-Nun.
  • Clandestine comets found in main asteroid belt - Earth oceans origin

    03/24/2006 2:26:05 AM PST · by S0122017 · 10 replies · 901+ views
    newscientist space ^ | 23 March 2006
    Clandestine comets found in main asteroid belt 19:00 23 March 2006 NewScientist.com news service Kimm Groshong You do not have to look to the outer edges of the solar system, or even out beyond Neptune to observe a reservoir of comets. A bevy of the ice-containing bodies lies disguised as main-belt asteroids between Mars and Jupiter, claim astronomers from the University of Hawaii, US. David Jewitt and Henry Hsieh have dubbed the new population "main belt comets". They describe three objects with near circular, flat orbits in the asteroid belt that stream volatile materials, producing an observable tail for weeks...
  • Kansas scientists probe mysterious possible comet strikes on Earth

    12/14/2009 5:27:46 AM PST · by decimon · 35 replies · 981+ views
    University of Kansas ^ | Dec 14, 2009 | Unknown
    An investigation by the University of Kansas' Adrian Melott and colleagues reveals a promising new method of detecting past comet strikes upon Earth and gauging their frequencyLAWRENCE, Kan. — It's the stuff of a Hollywood disaster epic: A comet plunges from outer space into the Earth's atmosphere, splitting the sky with a devastating shock wave that flattens forests and shakes the countryside. But this isn't a disaster movie plotline. "Comet impacts might be much more frequent than we expect," said Adrian Melott, professor of physics and astronomy at the University of Kansas. "There's a lot of interest in the rate...
  • We are all made of comet dust

    06/16/2013 12:50:32 AM PDT · by nickcarraway · 35 replies
    The National ^ | Jun 16, 2013
    Man owes a lot to chunks of rock and ice floating through space. From ancient jewellery to water and possibly even the beginnings of life itself, scientists are discovering that comets have contributed in many ways to the development of life on the planet, Robert Matthews writes Since their discovery in an Egyptian cemetery more than a century ago, a handful of metal beads have perplexed archaeologists. As jewellery, the beads seem decidedly downmarket, being made of nothing more glamorous than iron. Yet clearly their owner, dead for more than 5,000 years, held them in great esteem - as do...
  • Astronomy Picture of the Day -- Comets Lemmon and PanSTARRS Peaking

    03/05/2013 4:41:44 PM PST · by SunkenCiv · 8 replies
    NASA ^ | March 05, 2013 | (see photo credit)
    Explanation: Two impressive comets will both reach their peak brightness during the next two weeks. Taking advantage of a rare imaging opportunity, both of these comets were captured in the sky together last week over the Atacama desert in South America. Comet C/2012 F6 (Lemmon), visible on the upper left of the above image, is sporting a long tail dominated by glowing green ions. Comet C/2011 L4 (PanSTARRS), visible near the horizon on the lower right, is showing a bright tail dominated by dust reflecting sunlight. The tails of both comets point approximately toward the recently set Sun. Comet Lemmon...
  • Newly Discovered Comet May Hit Mars: Watch for Two Others Near Earth

    03/04/2013 9:03:58 PM PST · by Jack Hydrazine · 29 replies
    Science World Report ^ | 4MAR2013 | Catherine Griffin
    This year seems to be one for comets. In addition to the two projectiles that will zoom near Earth, a third one has recently been discovered. The newest one, though, won't fly by our planet. Instead, it will pass uncomfortably close to Mars in 2014. Named C/2013 A1, the comet will fly near the Red Planet on Oct. 19, 2014 according to preliminary orbital prediction models. The icy missile is thought to have first originated from the Oort Cloud, which is a hypothetical region containing billions of cometary nuclei located around our solar system. Comets have struck planets in the...
  • Approaching comet may outshine the moon

    12/31/2012 3:58:25 AM PST · by Olog-hai · 34 replies
    Reuters ^ | Fri Dec 28, 2012 5:28pm EST | Irene Klotz
    A comet blazing toward Earth could outshine the full moon when it passes by at the end of next year—if it survives its close encounter with the sun. The recently discovered object, known as comet ISON, is due to fly within 1.2 million miles (1.9 million km) from the center of the sun on Nov. 28, 2013 said astronomer Donald Yeomans, head of NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, Calif. As the comet approaches, heat from the sun will vaporize ices in its body, creating what could be a spectacular tail that is visible...
  • Newfound Comet Could Look Spectacular in 2013 ( Comet ISON )

    12/27/2012 6:32:20 AM PST · by Las Vegas Dave · 16 replies
    space.com ^ | 25 September 2012 | Joe Rao
    A newly discovered comet has the potential to put on a dazzling celestial display late next year, when it will be so bright you may be able to see it briefly in the daytime sky. The discovery of the object named Comet ISON was announced Monday (Sept. 24) by Russians Vitali Nevski and Artyom Novichonok, who detected it in photographs taken three days earlier using a 15.7-inch (0.4-meter) reflecting telescope of the International Scientific Optical Network (ISON), near Kislovodsk. The new comet is officially known as C/2012 S1. When first sighted, Comet ISON was 625 million miles (1 billion kilometers)...
  • New Comet Discovered—May Become "One of Brightest in History" (outshine the moon)

    09/28/2012 1:20:52 PM PDT · by NYer · 24 replies
    National Geographic ^ | September 27, 2012 | Andrew Fazekas
    Sky-watchers in Australia ogle comet Lovejoy late last year. If astronomers' early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a superbright comet, just discovered streaking near Saturn.Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say.The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What's more, 2012...
  • Newly spotted comet may outshine the full moon

    09/26/2012 6:29:10 PM PDT · by SunkenCiv · 89 replies
    New Scientist ^ | Tuesday, September 25, 2012 | Jeff Hecht
    Vitali Nevski and Artyom Novichonok, of the International Scientific Optical Network (ISON) in Russia, discovered comet C/2012 S1 (ISON) on 21 September via images taken with a 40-centimetre reflecting telescope. Other sky-watchers soon spotted it, and the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts, announced the find yesterday. From the combined observations, astronomers were able to trace the comet's recent path and find images of it dating back to late December 2011. From there they calculated a near-parabolic orbit that has comet ISON headed almost straight towards the sun. Astronomers at the Remanzacco Observatory in Italy think that...
  • Comet May Have Collided With Earth 13,000 Years Ago(MEXICO)

    07/15/2012 5:03:34 PM PDT · by ForGod'sSake · 49 replies
    Spacedotcom ^ | March 6, 2012 | Clara Moskowitz
    Central Mexico’s Lake Cuitzeo contains melted rock formations and nanodiamonds that suggest a comet impacted Earth around 12,900 years ago, scientists say. CREDIT: Israde et al. (2012) New evidence supports the idea that a huge space rock collided with our planet about 13,000 years ago and broke up in Earth's atmosphere, a new study suggests. This impact would have been powerful enough to melt the ground, and could have killed off many large mammals and humans. It may even have set off a period of unusual cold called the Younger Dryas that began at that time, researchers say. The...
  • Many Solar System Comets May Be Sun's Stolen Goods

    03/17/2012 11:10:14 PM PDT · by SunkenCiv · 17 replies
    Space dot com ^ | February 28, 2012 | Clara Moskowitz
    At least 5 percent of the comets orbiting our sun may have been stolen from other stars, scientists say. Our solar system is thought to include trillions of comets -- small chunks of rock and ice -- that circle the sun in a spherical swarm called the Oort cloud, a region that extendsabout 100,000 times the distance from the Earth to the sun in any direction. The average distance between the Earth and sun is 93 million miles (150 million kilometers). Now scientists suggest that many of these bodies may actually have originated around other stars and were snatched up...
  • Comet Lovejoy survives a brush with Sol ( Videos )

    12/16/2011 10:14:54 PM PST · by Ernest_at_the_Beach · 15 replies
    Watts Up With That? ^ | December 16, 2011 | Anthony Watts
    From Physorg.com Comet Lovejoy was only discovered a couple of weeks ago. It was supposed to melt as it came so close to the sun that the temperatures would hit several million degrees.But astronomers watching live with NASA telescopes were shocked when a bright spot emerged on the sun’s other side. Lovejoy lived.
  • Astronomy Picture of the Day -- Leonid Fireball over Tenerife

    11/23/2011 4:43:39 AM PST · by SunkenCiv · 8 replies
    NASA ^ | November 22, 2011 | (see photo credit)
    Explanation: Historically active, this year's Leonid meteor shower was diminished by bright moonlight. Still, faithful night sky watchers did see the shower peak on November 18 and even the glare of moonlight didn't come close to masking this brilliant fireball meteor. The colorful meteor trail and final flare was captured early that morning in western skies over the Canary Island Observatorio del Teide on Tenerife. Particles of dust swept up when planet Earth passes near the orbit of periodic comet Tempel-Tuttle, Leonid meteors typically enter the atmosphere at nearly 70 kilometers per second. Looking away from the Moon, the wide...
  • Astronomy Picture of the Day -- Comet and CME on the Sun

    10/05/2011 3:24:00 AM PDT · by SunkenCiv · 12 replies
    NASA ^ | October 05, 2011 | (see photo credit)
    Explanation: Did a sun-diving comet just cause a solar explosion? Probably not. This past weekend a comet dove toward the Sun and was followed very quickly by a Coronal Mass Ejection (CMEs) from the other side of the Sun. The first two sequences in the above video shows the spectacular unfolding of events as seen by the Sun-orbiting SOHO satellite, while the same events were also captured by both Sun-orbiting STEREO satellites. Now sungrazer comets that break up as they pass near the Sun are not all that rare -- hundreds have been cataloged over the past few years. CMEs...
  • Comet Theory Comes Crashing to Earth

    05/23/2011 5:43:19 PM PDT · by Renfield · 33 replies · 1+ views
    Miller-McCune ^ | 5-14-2011 | Rex Dalton
    It seemed like such an elegant answer to an age-old mystery: the disappearance of what are arguably North America’s first people. A speeding comet nearly 13,000 years ago was the culprit, the theory goes, spraying ice and rocks across the continent, killing the Clovis people and the mammoths they fed on, and plunging the region into a deep chill. The idea so captivated the public that three movies describing the catastrophe were produced. But now, four years after the purportedly supportive evidence was reported, a host of scientific authorities systematically have made the case that the comet theory is “bogus.”...
  • The Origin of Sunspots -- A New Hypothesis

    05/17/2011 2:33:40 PM PDT · by SunkenCiv · 19 replies
    American Geophysical Union ^ | December 2003 | J. Ackerman
    Recent observations of sunspots, the high temperature of the corona and CMEs strongly suggest that they are all caused by highly energetic solid bodies falling into the Sun. This hypothesis is consistent with the rapid (3000 mph) downward flow of gases in sunspot interiors observed by SOHO, their lower temperatures, and the presence of large quantities of water in their spectra. The high velocity of the incoming body entrains the surface gases, carrying them rapidly downward. The vaporization of the bodies cools the local gases and the water released from the bodies produces the observed spectra. Solar flares and CMEs...
  • Brian Marsden dies at 73; astronomer who tracked comets and asteroids

    11/20/2010 7:53:58 PM PST · by LibWhacker · 9 replies
    LATimes ^ | 11/20/10 | Thomas H. Maugh
    Astronomer Brian G. Marsden, a comet and asteroid tracker who stood sentinel to protect the Earth from collisions with interplanetary rocks and other remnants of the solar system's creation, died Thursday of cancer at Lahey Clinic Medical Center in Burlington, Mass. He was 73. Director emeritus of the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., Marsden was perhaps best known for his 1998 announcement that an asteroid known as 1997 XF11 might strike the Earth in 2028, causing untold damage. The announcement sparked additional studies which quickly showed that such an impact was unlikely. Marsden,...
  • Humans to Asteroids: Watch Out! (Russell Schweickart, former astronaut)

    10/27/2010 3:28:53 PM PDT · by neverdem · 14 replies
    NY Times ^ | October 25, 2010 | Russell Schweickart
    A FEW weeks ago, an asteroid almost 30 feet across and zipping along at 38,000 miles per hour flew 28,000 miles above Singapore. Why, you might reasonably ask, should non-astronomy buffs care about a near miss from such a tiny rock? Well, I can give you one very good reason: asteroids don’t always miss. If even a relatively little object was to strike a city, millions of people could be wiped out. Thanks to telescopes that can see ever smaller objects at ever greater distances, we can now predict dangerous asteroid impacts decades ahead of time. We can even use...
  • Perseid meteor shower is here - Tonight best after midnight

    08/12/2010 12:32:59 AM PDT · by Fred · 1 replies
    Seattle PI blog ^ | 081210 | Amy Rolph
    Showers are expected Thursday, but not the wet kind that have plagued Seattle all summer. The Perseid meteor shower will be visible Thursday night, and viewing conditions should be optimal. The meteor shower appears every year as the Earth enters a band of dust that trails the comet Swift-Tuttle. It's one of of the more reliable night-sky events for stargazers in Seattle, and this year's show could be easier to watch because of clear skies and limited moonlight.
  • Amateur photo of Comet McNaught passing by distant galaxy

    06/11/2010 6:41:53 AM PDT · by ETL · 14 replies · 947+ views
    SpaceWeather.com ^ | June 11, 2010
    One wonders... Did the inhabitants of galaxy NGC 891 duck when Comet McNaught flew past the edge-on spiral on the morning of June 8th? Mike O'Connor and Tristan Dilapo took this picture of the cosmic close encounter from Colden, New York: (click on photo to enlarge) "The comet was only 10 degrees above the horizon," says O'Connor. "Nevertheless, we got a good picture using a 12-inch telescope and an SBIG ST9-E camera."And, no, the denizens of that distant galaxy did not flinch, flee, duck or take notice in any way. NGC 891 is 30 million light years away, far removed...
  • Comets 'not cause of extinctions'

    08/04/2009 10:30:30 AM PDT · by BGHater · 8 replies · 643+ views
    BBC ^ | 02 Aug 2009 | Griet Scheldeman
    Comet strikes are an unlikely cause of past mass extinctions on Earth, according to computer simulations. Scientists used the simulations to model the paths of long-period comets, to determine the likelihood of these "dirty snowballs" striking our planet. The University of Washington, Seattle, research appears in Science journal. How many mass extinctions in Earth's history were caused by these icy bodies crashing into our planet has been a subject of considerable debate. Many scientists agree that an asteroid strike 65 million years ago wiped out the dinosaurs. But there is uncertainty about how many other such events were triggered by...
  • Jupiter: Our Cosmic Protector? (How the planet protects us from cosmic disaster)

    07/26/2009 7:02:22 PM PDT · by SeekAndFind · 13 replies · 593+ views
    New York Times ^ | 7/26/2009 | Dennis Overbye
    Jupiter took a bullet for us last weekend. An object, probably a comet that nobody saw coming, plowed into the giant planet’s colorful cloud tops sometime Sunday, splashing up debris and leaving a black eye the size of the Pacific Ocean. This was the second time in 15 years that this had happened. The whole world was watching when Comet Shoemaker-Levy 9 fell apart and its pieces crashed into Jupiter in 1994, leaving Earth-size marks that persisted up to a year. That’s Jupiter doing its cosmic job, astronomers like to say. Better it than us. Part of what makes the...
  • Jupiter Hit by an Astronomical Object

    07/21/2009 10:05:28 AM PDT · by Osnome · 26 replies · 1,160+ views
    MINA ^ | Tuesday, 21 July 2009 | MINA
    Scientists have found evidence that another object has bombarded Jupiter, exactly 15 years after the first impacts by the comet Shoemaker-Levy 9. Following up on a tip by an amateur astronomer, Anthony Wesley of Australia, that a new dark "scar" had suddenly appeared on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and noon EDT) scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., using NASA's Infrared Telescope Facility at the summit of Mauna Kea, Hawaii, gathered evidence indicating an impact.
  • When Comets Attack: Solving the Mystery of the Biggest Natural Explosion in Modern History

    05/07/2009 8:47:49 AM PDT · by JoeProBono · 19 replies · 1,192+ views
    popularmechanics ^ | May 7, 2009 | Mark Anderson
    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...
  • Comets may be spawned when mum breaks up [circling the wagons cont'd]

    07/27/2008 9:57:14 AM PDT · by SunkenCiv · 4 replies · 159+ views
    New Scientist ^ | Saturday, July 26, 2008 | David Shiga
    Are comets born in great swarms? The puzzling abundance of comets in short solar orbits has led a pair of astronomers to suggest that they are fragments of larger bodies that crumbled as they entered the inner solar system. Short-period comets take less than 200 years to circle the sun and are thought to originate in the Kuiper belt of icy objects beyond Neptune. Some Kuiper-belt objects (KBOs) are in vulnerable orbits that allow the gravity of the outer planets to tug them inwards, where the sun's heat turns them into comets. However, there seem to be too few KBOs...
  • Did Comets Cause Ancient American Extinctions?

    05/07/2008 6:40:10 PM PDT · by blam · 29 replies · 475+ views
    National Geographic News ^ | 5-6-2008 | Anne Casselman
    Did Comets Cause Ancient American Extinctions?Anne Casselman for National Geographic NewsMay 6, 2008 Debate has heated up over a controversial theory that suggests huge comet impacts wiped out North America's large mammals nearly 13,000 years ago. The hypothesis, first presented in May 2007, proposes that an onslaught of extraterrestrial bodies caused the mass extinction known as the Younger Dryas event and triggered a period of climatic cooling. The theory has been debated widely since it was introduced, but it drew new scrutiny in March at the annual meeting of the Society for American Archaeology annual meeting in Vancouver, Canada. Stuart...
  • Dust samples prompt rethink about comets (rock dust retrieved from a comet called Wild 2)

    01/25/2008 4:13:52 PM PST · by NormsRevenge · 3 replies · 86+ views
    Reuters on Yahoo ^ | 1/25/08 | Will Dunham
    WASHINGTON (Reuters) - Samples of rock dust retrieved from a comet called Wild 2 are forcing scientists to alter they way they think about these intriguing objects that streak through our solar system. A chemical analysis of the samples brought back to Earth by NASA's Stardust spacecraft showed that the comet is much more like an asteroid than scientists had expected. Comets are celestial bodies made of rock, dust and ice with characteristic tails of gas and dust streams that are formed in the solar system's distant, frigid reaches. A long-standing notion had been they were sort of a frozen...
  • The 1 September 2007 Aurigid outburst. [Meteor shower alert!]

    08/28/2007 6:17:36 PM PDT · by IonImplantGuru · 40 replies · 1,454+ views
    For FReepers in the western US (& Hawaii), I have a heads-up for - potentially - a really nice meteor display early this coming Saturday morning. Points east will not be able to see the peak of the display because - at 4:36 AM PDT - twilight or daytime will already have occurred. The best show will be looking to the northeast. There will be a 3/4 full waning moon high in the sky, so if the observer can shield oneself from the moon behind an obstacle (phone pole, house, car, tree, etc.) the viewing will be improved. I was...
  • Comet Theory Collides With Clovis Research, May Explain Disappearance of Ancient People

    08/03/2007 11:29:34 PM PDT · by ForGod'sSake · 121 replies · 4,803+ views
    June 28, 2007 Comet theory collides with Clovis research, may explain disappearance of ancient people A theory put forth by a group of 25 geo-scientists suggests that a massive comet exploded over Canada, possibly wiping out both beast and man around 12,900 years ago, and pushing the earth into another ice age. University of South Carolina archaeologist Dr. Albert Goodyear said the theory may not be such "out-of-this-world" thinking based on his study of ancient stone-tool artifacts he and his team have excavated from the Topper dig site in Allendale, as well as ones found in Georgia, North Carolina and...
  • A possible impact crater for the 1908 Tunguska Event

    06/22/2007 11:46:00 AM PDT · by Mike Darancette · 25 replies · 7,696+ views
    Terra Nova ^ | 7/01/2007 | Terra Nova
    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...
  • Comet May Have Doomed Mammoths

    05/26/2007 6:12:53 AM PDT · by Renfield · 32 replies · 1,982+ views
    Red Orbit ^ | 5-26-07 | Betsy Mason
    mammoth some 12,900 years ago. A team of two dozen scientists say the culprit was likely a comet that exploded in the atmosphere above North America. The explosions sent a heat and shock wave across the continent, pelted the ground with a layer of telltale debris, ignited massive wildfires and triggered a major cooling of the climate, said nuclear analytic chemist Richard Firestone of Lawrence Berkeley Laboratory, one of the scientists who presented the controversial new theory Thursday at a conference of the American Geophysical Union in Acapulco. At least 15 species, mostly large mammals including mammoths, mastadons, giant ground...
  • Comets And Disaster In The Bronze Age

    04/30/2007 4:38:09 PM PDT · by blam · 63 replies · 2,021+ views
    British Archaeology ^ | December 1997 | Benny Peiser
    Comets and disaster in the Bronze AgeCosmic impact is gaining ground as an explanation of the collapse of civilisations, writes Benny Peiser At some time around 2300BC, give or take a century or two, a large number of the major civilisations of the world collapsed. The Akkadian Empire in Mesopotamia, the Old Kingdom in Egypt, the Early Bronze Age societies in Israel, Anatolia and Greece, as well as the Indus Valley civilisation in India, the Hilmand civilisation in Afghanistan and the Hongshan Culture in China - the first urban civilisations in the world - all fell into ruin at more...
  • Comet's course hints at mystery planet [ from 2001 ]

    08/18/2006 2:36:59 PM PDT · by SunkenCiv · 32 replies · 421+ views
    Govert Schilling ^ | last updated February 5th, 2002 | Govert Schilling
    The giant comet, known as 2000 CR105, measures some 400 kilometers across... Brett Gladman of the Observatoire de la Côte d'Azur in Nice, France, and his colleagues have discovered... that 2000 CR105 orbits the sun in 3175 years and never comes closer than 6.6 billion kilometers--well beyond Neptune's orbit. The farthest point of the highly eccentric orbit lies 58.2 billion kilometers from the sun--13 times as far as Neptune... One possibility is that 2000 CR105's orbit evolved into its freakish shape gradually, due to small, periodic gravitational nudges from Neptune. Computer simulations imply that such a "diffusive chaos" scenario is...
  • Sizzling Comets Circle a Dying Star

    03/15/2006 7:51:58 AM PST · by SunkenCiv · 14 replies · 436+ views
    NASA press release ^ | July 11, 2001 | Dr. Tony Phillips
    IRC+10216, also known as CW Leonis, was once a well-behaved main-sequence star as our own Sun is now... When astronomers turned the satellite toward IRC+10216 they discovered a substantial cloud of water vapor about 100 AU across. ("AU" --short for Astronomical Unit-- is a unit of length used by astronomers. One AU equals the mean distance between Earth and the Sun.) "There must be about four Earth-masses of frozen water around IRC+10216 to produce the vapor cloud we see," says Melnick. The water vapor probably does not come from the vaporization of oceans on an Earth-like planet, because there wouldn't...
  • Elated Scientists Say Space-Dust Mission Exceeded Expectations

    01/19/2006 10:36:07 PM PST · by neverdem · 39 replies · 812+ views
    NY Times ^ | January 20, 2006 | WARREN E. LEARY
    The Stardust mission to bring back samples of comet and interstellar dust was more successful than they had hoped, scientists said yesterday. The 100-pound sample container from the seven-year mission, which landed on the salt flats of Utah on Sunday, captured thousands of particles, perhaps even a million, that originated at the edge of the solar system or from distant stars, they said. While they had expected mostly microscopic samples, the researchers said, a surprising number of the particles were large enough to be seen with the naked eye. "It exceeded all of our grandest expectations," Donald Brownlee of the...
  • Scientist: Comets Blasted Early Americans

    10/28/2005 6:33:11 PM PDT · by NormsRevenge · 48 replies · 1,824+ views
    ap on Yahoo ^ | 10/28/05 | Meg Kinnard - ap
    COLUMBIA, S.C. - A supernova could be the "quick and dirty" explanation for what may have happened to an early North American culture, a nuclear scientist here said Thursday. Richard Firestone said at the "Clovis in the Southeast" conference that he thinks "impact regions" on mammoth tusks found in Gainey, Mich., were caused by magnetic particles rich in elements like titanium and uranium. This composition, the Lawrence Berkeley National Laboratory scientist said, resembles rocks that were discovered on the moon and have also been found in lunar meteorites that fell to Earth about 10,000 years ago. Firestone said that, based...
  • (WNBA)Comets' Sheryl Swoopes opens up about being gay ("Do I think I was born this way? No")

    10/26/2005 5:40:43 AM PDT · by truthandlife · 109 replies · 5,919+ views
    Houston Comets forward Sheryl Swoopes is opening up about being a lesbian, telling a magazine that she's "tired of having to hide my feelings about the person I care about." Swoopes, honored last month as the WNBA's Most Valuable Player, told ESPN The Magazine for a story on newsstands today that she didn't always know she was gay and fears that coming out could jeopardize her status as a role model. "Do I think I was born this way? No," Swoopes said. "And that's probably confusing to some, because I know a lot of people believe that you are." Swoopes,...
  • Composition of a Comet Poses a Puzzle for Scientists

    09/07/2005 12:10:01 PM PDT · by neverdem · 47 replies · 1,289+ views
    NY Times ^ | September 7, 2005 | KENNETH CHANG
    Although comets form at the frigid edges of the solar system, they appear somehow to contain minerals that form only in the presence of liquid water, and at much warmer temperatures, scientists are reporting today. On July 4, as planned, part of the Deep Impact spacecraft - essentially an 820-pound, washing machine-size bullet - slammed into the comet Tempel 1 at 23,000 miles an hour. The collision tossed up thousands of tons of ice and dust from the comet that were observed by telescopes on Earth as well as small flotilla of spacecraft. One of the observers was the Spitzer...
  • Deep Impact - First Impressions - Electric Universe Theorists response

    07/06/2005 2:32:43 AM PDT · by Swordmaker · 10 replies · 933+ views
    THUNDERBOLTS PICTURE OF THE DAYExploring the electric universe From ancient mythology to cosmic plasma discharge   homethe book quotes picture of the day picture archive subject index the film(video clips) products Contact usElectric Universe: Holoscience Electric Cosmos The Universe Dragon Science Plasma Cosmology Society for Interdisciplinary Studies     Jul 05, 2005Deep Impact?First ImpressionsThe Deep Impact was an amazing show, and there will be much more information to come.In advance of the event we set forth our expectations as explicitly as possible. Therefore, we urge readers of this page to refer to our previous Picture of the Day.We also...
  • For the First Time a Spacecraft Impacts With Comet

    07/04/2005 11:03:46 AM PDT · by neverdem · 36 replies · 1,107+ views
    NY Times ^ | July 4, 2005 | WARREN E. LEARY
    WASHINGTON, July 4 -- NASA's Deep Impact spacecraft lived up to its name early Monday when it slammed into a comet with such force that the resulting blast of icy debris stunned scientists with its size and brightness. With the flyby stage of the two-part spacecraft watching from a safe distance, an 820-pound, copper-core "impactor" craft smashed into the nucleus of comet Tempel 1 at 23,000 miles per hour, sending a huge, bright spray of debris into space. "The impact was spectacular," said Dr. Michael A'Hearn of the University of Maryland, the projects principal scientist. "It was much brighter than...
  • Predictions on ?Deep Impact?

    07/03/2005 7:06:44 PM PDT · by Swordmaker · 70 replies · 2,127+ views
    THUNDERBOLTS PICTURE OF THE DAYExploring the electric universe From ancient mythology to cosmic plasma discharge Credit: NASA/JPL/UMD Artwork by Pat Rawlings the book quotes picture of the day picture archive subject index the film(video clips) products Contact usElectric Universe: Holoscience Electric Cosmos The Universe Dragon Science Plasma Cosmology Society for Interdisciplinary Studies     Jul 04, 2005Predictions on "Deep Impact"With the imminent arrival of the "Deep Impact" spacecraft at the comet Tempel 1, it is time to test competing theories on the nature of comets. The predictions and lines of reasoning offered here will set the stage for future...
  • Spacecraft Is on a Collision Course With a Comet, Intentionally (Happy 4th of July!)

    06/28/2005 4:43:23 PM PDT · by neverdem · 24 replies · 968+ views
    NY Times ^ | June 28, 2005 | WARREN E. LEARY
    WASHINGTON, June 27 - A two-stage spacecraft called Deep Impact is about to make an ambitious attempt to dissect a comet by slamming into it and blowing some of its innards into space for all to see. Launched from Florida on Jan. 12, NASA's Deep Impact is nearing the end of a finely calibrated 268-million-mile journey that puts comet Tempel 1 within its sights. An 820-pound copper-core "impactor" is to smash into the comet's nucleus at 23,000 miles an hour in the early hours of July 4, an unprecedented event that will, if all goes well, be witnessed by its...
  • Comet put on list of potential Earth impactors

    06/02/2005 9:04:31 AM PDT · by SunkenCiv · 46 replies · 3,184+ views
    New Scientist ^ | 1 June 2005 | David L Chandler
    On 26 May, JPL's unique orbital calculation software determined that Comet Catalina was on what could possibly be a collision course with Earth, though the odds of such an impact were small: just 1 chance in 300,000 of a strike on June 11, 2085. Based on the 980-metre size estimate, that would produce a 6-gigaton impact - equivalent to 6 billion tonnes of TNT. Astronomers expected the addition of further observations to the calculations to rule out any possibility of a collision, as happens with most newly-seen objects. But that did not quite happen. The comet's predicted pathway actually drew...
  • Spacecraft launched on mission to smash comet

    01/12/2005 7:52:25 PM PST · by bayourod · 16 replies · 590+ views
    CAPE CANAVERAL, Fla. — A NASA spacecraft with a Hollywood name — Deep Impact — blasted off today on a mission to smash a hole in a comet and give scientists a glimpse of the frozen primordial ingredients of the solar system. With a launch window only one second long, Deep Impact rocketed away at the designated moment on a six-month, 268-million-mile journey to Comet Tempel 1. It will be a one-way trip that NASA hopes will reach a cataclysmic end on the Fourth of July. "We are on our way," an excited Michael A'Hearn of the University of Maryland,...