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Sun's Movement Through Milky Way Regularly Sends Comets Hurtling, Coinciding With Mass Life ExtinctionsA large body of scientific evidence now exists that support the hypothesis that a major asteroid or comet impact occurred in the Caribbean region at the boundary of the Cretaceous and Tertiary periods in Earth's geologic history. Such an impact is suspected to be responsible for the mass extinction of many floral and faunal species, including the large dinosaurs, that marked the end of the Cretaceous period. (Credit: Art by Don Davis / Courtesy of NASA) ScienceDaily (May 2, 2008) — The sun's movement through the Milky...

Had you searched the sky with a telescope just a few hundred thousand years ago, you would have struggled to find a red planet. Instead, you would have seen a gleaming-white ice ball where Mars should be. A team of astronomers led by Isaac Smith, an astrophysicist at the Southwest Research Institute in Boulder, Colorado, has collected the first concrete evidence that Mars has just exited an extreme ice age, one so intense it would have put Earth's recent frosty foray to shame. Using cameras and a radar-pinging device on board NASA's Mars Reconnaissance Orbiter, Smith's team deduced this history...

Space impact 'saved Christianity' By Dr David Whitehouse BBC News Online science editor Did a meteor over central Italy in AD 312 change the course of Roman and Christian history? About the size of a football field: The impact crater left behind A team of geologists believes it has found the incoming space rock's impact crater, and dating suggests its formation coincided with the celestial vision said to have converted a future Roman emperor to Christianity. It was just before a decisive battle for control of Rome and the empire that Constantine saw a blazing light cross the sky and...

A metallic asteroid may have coincided with the fall of Rome, says Duncan Steel Thursday February 6, 2003 The Guardian In the early fifth century, rampaging Goths swept through Italy. Inviolate for 1,100 years, Rome was sacked by the hordes in 410 AD. St Augustine's apologia, the City of God, set the tone for Christians for the next 16 centuries. But the Rome of that era came close to suffering a far worse calamity. A small metallic asteroid descended from the sky, making a hypervelocity impact in an Apennine valley just 60 miles east of the city. This bus-sized lump...

A volcano on Mars half the size of France spewed so much lava 3.5 billion years ago that the weight displaced the Red Planet's outer layers, according to a study released Wednesday. Mars' original north and south poles, in other words, are no longer where they once were. The findings explain the unexpected location of dry river beds and underground reservoirs of water ice, as well as other Martian mysteries that have long perplexed scientists, the lead researcher told AFP. "If a similar shift happened on Earth, Paris would be in the Polar Circle," said Sylvain Bouley, a geomorphologist at...

Jafar Arkani-Hamed of McGill University discovered that five impact basins--dubbed Argyre, Hellas, Isidis, Thaumasia and Utopia--form an arclike pattern on the Martian surface. Three of the basins are well-preserved and remain visible today. The locations of the other two, in contrast, were inferred from measurements of anomalies in the planet's gravitational field... a single source--most likely an asteroid that was initially circling the sun in the same plane as Mars--created all five craters. At one point the asteroid passed close to the Red Planet... and was broken apart by the force of the planet's gravity. The resulting five pieces subsequently...

New Theory: Catastrophe Created Mars' Moons By Leonard David Senior Space Writer posted: 07:00 am ET 29 July 2003 PASADENA, California – The two moons of Mars – Phobos and Deimos – could be the byproducts of a breakup of a huge moon that once circled the red planet, according to a new theory. The capture of a large Martian satellite may have taken place during or shortly after the formation of the planet, with Phobos and Deimos now the surviving remnants. Origin of the two moons presents a longstanding puzzle to which one researcher proposed the new solution at...

Antarctica is known by meteorite specialists as a fruitful hunting ground, because the rocks are collected from their landing sites by glacial flows and transported to concentrated dumping-grounds. ... Among this Antarctic haul, however, researchers have noticed that iron-rich meteorites - whether partly or wholly made of the metal - are surprisingly scarce, compared to the percentage collected in other places around the world. Dr Joy and her colleagues think they may have discovered why. They froze two small meteorites of similar size and shape, one made of iron and the other rocky and non-metallic, inside blocks of ice. A...

Impact cratering is one of the most fundamental geological processes. On many planets, impact craters are the dominant geological landform. On Earth, erosion, plate tectonics, and volcanic resurfacing continually destroy the impact cratering record, but even here, the geological, biological, and environmental effects of impact cratering are apparent. Impact events are destructive and have been linked to at least one of the 'big five' mass extinctions over the past 540 million years. Intriguingly, impact craters can also have beneficial effects. Many impact craters are associated with economic metalliferous ore deposits and hydrocarbon reservoirs. This Special Paper from The Geological...

In 1996 in the Egyptian Museum in Cairo, Italian mineralogist Vincenzo de Michele spotted an unusual yellow-green gem in the middle of one of Tutankhamun's necklaces. The jewel was tested and found to be glass, but intriguingly it is older than the earliest Egyptian civilisation. Working with Egyptian geologist Aly Barakat, they traced its origins to unexplained chunks of glass found scattered in the sand in a remote region of the Sahara Desert. But the glass is itself a scientific enigma. How did it get to be there and who or what made it? Thursday's BBC Horizon programme reports an...

Two billion years ago a meteorite 10km in diameter hit the earth about 100km southwest of Johannesburg, creating an enormous impact crater. This area, near Vredefort in the Free State, is now known as the Vredefort Dome... The meteorite, larger than Table Mountain, caused a thousand-megaton blast of energy. The impact would have vaporised about 70 cubic kilometres of rock - and may have increased the earth's oxygen levels to a degree that made the development of multicellular life possible... The original crater, now eroded away, was probably 250 to 300 kilometres in diameter. It was larger than the Sudbury...

Supervolcanoes, massive eruptions with potential global consequences, appear not to follow the conventional volcano mechanics of internal pressure building until the volcano blows. Instead, a new study finds, such massive magma chambers might erupt when the roof above them cracks or collapses. Knowledge of triggering mechanisms is crucial for monitoring supervolcano systems, including ones that lie beneath Yellowstone National Park and Long Valley, California, according to the study led by Patricia Gregg, University of Illinois professor of geology, in collaboration with professor Eric Grosfils of Pomona College and professor Shan de Silva of Oregon State University. The study was published...

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...

A color composite image of the June 3, 2010, Jupiter impact flash. Credit: Anthony Wesley observing from Broken Hill, Australia. In a paper published Thursday in the Astrophysical Journal Letters, a group of professional and amateur astronomers announced that Jupiter is getting hit surprisingly often by small asteroids, lighting up the giant planet's atmosphere with frequent fireballs. "Jupiter is a big gravitational vacuum cleaner," said co-author and JPL astronomer Glenn Orton. "It is clear now that relatively small objects left over from the formation of the solar system 4.5 billion years ago still hit Jupiter frequently." The impacts are...

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,...

Crater patterns on Vesta and Ceres could help pinpoint when Jupiter began to form during the evolution of the early Solar System. A study modelling the cratering history of the largest two objects in the asteroid belt, which are believed to be among the oldest in the Solar System, indicates that the type and distribution of craters would show marked changes at different stages of Jupiter’s development. Results will be presented by Dr Diego Turrini at the European Planetary Science Congress in Potsdam, Germany, on Monday 14 September. The study, carried out by scientists at the Italian National Institute for...