Abbott's work is especially important because she is studying the oceans, not land. Most of what's known about past space-object strikes comes from the study of land craters. But three-quarters of Earth's surface is water; Abbott reasoned that three-quarters of space objects must crash into the seas. Her work suggests a lot of comets and large rocks have hit the seas, many recently in geologic terms. As recently as a decade ago, most scientists assumed that space-rock strikes powerful enough to cause general devastation happen only every million years or so. Now it looks like they are far more frequent. If a rock comparable to the one that struck the Indian Ocean 4,800 years ago struck today in Kansas, half the population of the United States might die. And as TMQ endlessly points out, what is NASA doing about this? Absolutely nothing.

NASA will fund this if the agency is assured it will be incredibly expensive and serve no purpose.

NASA continues to waste about 10 billion of your tax dollars annually on a space station project that had no scientific value, existing solely to justify money for aerospace contractors and staff budgets at NASA manned-flight centers. NASA plans to waste 200-500 billion of your tax dollars on return-to-the-Moon missions that don't even have a theoretical justification -- the sole purpose of return-to-the-Moon is money for NASA insiders. Yet if a comet or large meteor was spotted heading toward our world, NASA could do nothing. And NASA isn't even researching possible anti-space-rock technology. No agency of your government wastes taxpayers' money more cynically or systematically than the National Aeronautics and Space Agency. If a big space object strikes the Earth, sending humanity's survivors back into the Dark Ages, our descendents will consider the present Washington government history's worst collections of fools for doing nothing while there was time.

Subramanyan Chandrasekhar, one of the leading 20th-century astronomers, won a Nobel Prize for his 1930s studies that maintained the most common category of exploding stars, called the Type Ia supernova, could not exceed about 1.4 times the mass of our sun; this seemed to impose an upper boundary on the amount of destruction such a supernova explosion could cause. But the Toronto researchers observed a Type Ia supernova, dubbed SNLS-03D3bb, that reached about two solar masses before detonating, and thus released far more radiation than was thought possible. There's another implication. Partly owing to Chandrasekhar's arguments, it was assumed all Type Ia supernovae explode with about the same luminosity, meaning their light level could be used to estimate the expanse between the Milky Way and distant galaxies. (If they're all giving off approximately the same amount of light, relative measurements allow you to estimate how far away they are.) Current estimates of the size and age of the universe, and its rate of expansion, rely on the assumption that Type Ia supernovae obey the Chandrasekhar limit. If it turns out this class of exploding stars varies significantly, all bets might be off about how large and old the universe is, or its rate of expansion.

He thought there was a limit to the destructive power of nature. Umm, looks like he thought wrong.

Now consider this. Since Edwin Hubble's discovery in 1929 that the universe was not static but expanding, theorists have debated whether the expansion would continue forever, gradually slow down or eventually reverse as gravity overcame the outward momentum of the Big Bang and pulled the stuff of the firmament back to its starting point. (The latter conjecture is called the Big Crunch.) Researchers using Type Ia supernova as measuring sticks declared in 1998 that cosmic expansion was accelerating, which nobody's theory predicted. The galaxies could not be speeding up unless energy were somehow being added to them, which caused cosmologists to speculate that mysterious "dark energy" permeates the universe and functions as the mirror image of gravity. No physicist has offered even the vaguest explanation of where dark energy originates or what powers it. (General relativity theory does offer an explanation of how gravity derives its power to pull.) Yet even though the dark energy concept requires you to believe that most of the energy of the universe is undetectable and so far inexplicable, physicists rapidly have accepted the idea that dark energy exists and even might be the dominant force of the cosmos. What if it turns out the universe is not accelerating, that the apparent rising rate of expansion is a data error caused by the false assumption that all Type Ia supernovas have a standard brightness? Then physicists will have to announce that dark energy never existed in the first place. But trust us, we're experts!

ELEANOR HALL: Over the last two days, police and news organisations in South Australia and western Victoria have been inundated with reports of mysterious lights in the night sky.

Some have described a fireball shooting across the horizon just before sunset, while callers in north-west Victoria have reported seeing a bright object flying across the sky.

The Astronomical Society of South Australia's Dr Tony Beresford has told Nance Haxton that while the sightings have sparked some UFO speculation, the cosmic mystery is most likely a meteor.

TONY BERESFORD: It was just one particular meteor which was widely observed. It was observed from around the metropolitan area to, I suspect, over in the border regions of Victoria and New South Wales.

NANCE HAXTON: And how do we know that it was a meteor?

TONY BERESFORD: Well, it was a short time, it was moving quite fast, faster than a satellite would've and there were no satellites due to come in.

NANCE HAXTON: And are there any reports of what happened to that meteor? I mean, does it burn up before landing or...

TONY BERESFORD: This one almost certainly did. It's... in fact, I have several reports which indicated at the end it more or less exploded.

NANCE HAXTON: How common is it for meteors such as this to be seen so brightly and be reported by people?

TONY BERESFORD: Well, about once a year or so, maybe twice.

NANCE HAXTON: So meteors are really falling from the sky all the time, it's just sometimes we see them?

TONY BERESFORD: Some, yes. We're in a cosmic shooting gallery. There are several moderately recent craters in the Australian continent, but the most recent appreciable-sized one is of course the very famous meteor crater in Arizona, only about 50,000 years ago.

NANCE HAXTON: 50,000 years ago? So hopefully our number's not coming up for a while yet?

TONY BERESFORD: Well, you don't... you never know. I'm one of these people who think we should do proper surveys for an asteroid that could possibly impact the earth, because we... if we did find one then we could probably divert it enough. You don't have to change its orbit very much.

The Australian Government doesn't believe in it, but the Americans are spending money employing two people up at Siding Spring looking for it.

NANCE HAXTON: You think that the risk of an asteroid hitting earth is enough that Australia should really look at taking more note of the risk?

TONY BERESFORD: Yes, yes they should. The risk is very small, but the number... the possible global consequences are enormous.

ELEANOR HALL: That's the Astronomical Society of South Australia's Dr Tony Beresford speaking to Nance Haxton.

"An investigative group of the department of interior affairs of
the Krasnoyarsk territory and representatives of the transport
prosecutor's office and Rosavianadzor were sent to the scene of the
crash," the department said.

The Siberian regional center of the Russian Emergency Situations
Ministry told Interfax it cannot confirm the crash. A Mil Mi-8
helicopter flew over the scene and no traces of any crash were detected,
it said.

The mountain of rubble swept into the sea at more than 200 mph, pulverized the sea bed and changed thick layers of soft marine sediment into jelly. It also started an underwater mudslide that flowed for hundreds of miles.

Researchers at the National Institute of Geology and Volcanolgy in Italy have also linked the tsunami with the mysterious abandonment of Atlit-Yam, a Neolithic village located along the coast of present-day Israel.

When archeologists discovered the village about 20 years ago, they found evidence of a sudden evacuation, including a pile of fish that had been gutted and sorted but then left to rot.

"A tsunami was not suspected before," said lead researcher Maria Pareschi.

To create their computer simulation, researchers used sonar-equipped boats to survey seafloor sediment displaced by the Mt. Etna avalanche.

Their recreation suggests the tsunami's waves reached heights of up to 130 feet and maximum speeds of up to 450 mph, making it more powerful than the Indonesian tsunami that killed more than 180,000 people in 2004.

According to Pareschi, if the same tsunami struck today, Southern Italy would be covered with water within the first 15 minutes. An hour later the waves would reach Greece's western coasts. After an hour and a half, the city of Benghazi in Northern Africa would be hit. At the three and a half hour mark, the waves would have traversed the entire Mediterranean to reach the coasts of Israel, Lebanon and Syria.

"Should the Neolithic Etna tsunami have occurred today, the impact is tremendous because the Eastern Mediterranean coasts are very inhabited ones," Pereschi said.

Avalanches and minor eruptions still occur on Mt. Etna today, but so far, nothing approaching the magnitude of the ancient event.

One thing about the archer was strange. He was missing a kneecap, requiring him to walk with one leg rigid. Bone deterioration suggested that the deformity took place years before his death. He was an improbable warrior, more likely a rich trader. Besides, near him lay a younger male revealed (such being the wonders of science) as a close relative brought up in south-east England. So what was this wealthy but disabled man doing in the shadow of Stonehenge, far from his and his putative son's birthplace?

Cut to the hallowed meeting room of the Society of Antiquaries in London last October. It was packed with excited Stonehenge pundits (the serious ones), gathered to hear news from the front. The origin of Stonehenge is British archaeology's oldest unsolved mystery, its Fermat's last theorem. How the four-ton bluestones were brought to Salisbury Plain from the Preseli hills of south Wales has been answered by engineers, but nobody has found out why.

Why go to the colossal expense of such transportation, when Stonehenge's sandstone monoliths were dragged from down the road at Marlborough? What was so special about the bluestones? To this the Gog and Magog of Stonehenge studies, Professors Geoff Wainwright and Timothy Darvill, were to give their answer. Theirs was archaeology's noblest endeavour, to pull the sword of meaning from the stone of time.

Darvill teased his audience by asking it to vote on half a dozen Stonehenge theories, many of them beloved by colleagues in the hall. Was it perhaps a fortress, a temple, an astronomical device, or a ring of ancestors turned to stone? None of these explained the need for such a gargantuan effort of trans-shipment. What was it about Wales that Wiltshire could not offer?

The answer had to lie in Preseli itself, in the hills of Carn Menyn and Carn Goedog where Stonehenge's dolerite and rhyolite bluestones were quarried. (They are still littered with the prehistoric quarrymen's discarded monoliths.) This rolling landscape has become intensive archaeological hunting ground. Wainwright, Darvill and Bournemouth University have crawled every inch. Somewhere in these wild moors and rocky outcrops must be the key to Stonehenge.

What is most remarkable about Preseli is the plethora of springs on the hillside. Many "holy wells" have been ascribed miraculous healing powers throughout history. But Preseli's are remarkable for their number and for the dolmens, enclosures and barrows surrounding the area. More remarkable still, in front of each are bluestones, rearranged and decorated as if to create an altar and a pool. This was clearly a place of prehistoric pilgrimage, and the bluestones were thought to hold its magic.

By the agrarian revolution of the third millennium BC Stonehenge was already an important site, but its extension about 2300BC was clearly intended by its guardians to make it a major pilgrimage attraction. This needed some sensational draw, and what could be more sensational than a henge composed of the fabled Preseli bluestones, fount of a hundred holy wells? It was worth any Olympian expense.

The medieval historian Geoffrey of Monmouth told of a belief in the healing power of Stonehenge's stones, brought by Arthur's magician, Merlin, "from Ireland", where stones have long had magic properties. Geoffrey's stories are ridiculed, but his folk memory might contain a grain of truth. Could the appeal of the bluestones lie not in ancestor worship or astronomical ritual but in the power these objects were thought to hold back in Preseli? In his new book, Stonehenge: Biography of a Landscape, Darvill points out that the arrangement of the stones at Stonehenge even reflects their geological location back in Wales.

Stonehenge was distinct among British henges - in its scale and spacious setting, and in the exceptional number of burial mounds round it. As Darvill says, it was "constantly being remodelled and changed over a period of perhaps a thousand years ... getting larger, more grand and more complicated". True its architecture is dominated by astronomical calculations, implying a priesthood and time-related rituals. But this would have meant nothing to ordinary mortals. What drew them to Stonehenge from across Europe must have been specific, a reputation for relief from disease and disability.

Throughout history religion has sold itself as offering salvation in this life as well as the next. The mass appeal of the early church lay in the quackery of relics and miracles. In many cultures priests are still medicine men. This may embarrass theologians, but it rarely embarrassed monks or missionaries. Monasteries were the teaching hospitals of their day and reliquaries their medicine chests. Miraculous relics changed hands for vast sums (and vast wars). Pretending to save bodies was as profitable as pretending to save souls, if more vulnerable to disproof.

That is why the 10th-century monks of Ely stole the remains of St Withburga from her church at East Dereham, eager for its large pilgrim income. That is why the canons of Windsor in 1478 robbed the tomb of "Doctor" Schorne of North Marston in Buckinghamshire. Schorne was a quack rector who invented a cure for gout (getting his patients to wash in his hugely profitable well). He was even revered as a saint. By relocating his corpse to Windsor the canons hoped to raise funds for their new St George's Chapel - and did. They were even forced to pay compensation to North Marston. The shrine of Holywell in Clwyd is still visited by devout Catholics, who change into swimming costumes to plunge into the holy waters. The line between faith healing and alternative medicine has always been a fine one.

The curative properties in wells relate, if at all, to their cleanliness and chemical composition. To the best of my knowledge there has been no analysis of Preseli's water to see if it has any "spa" components such as iron salts. Either way, moving the bluestones was a massive leap of medical faith. But it was one that clearly worked. As Darvill points out, the burial mounds round Stonehenge are not just unprecedented in their number but also in the deformities of their inmates.

I find this theory convincing. The joy of archaeology is that it licenses wild conjecture by subjecting it to the relentless test of science. Here it cries, plus ça change ... In the third millennium BC - as in the third AD - the rich would go anywhere and believe any nonsense if they thought it might win them health and longevity. The Amesbury archer was a Swiss migrant taken by his son to Europe's most famous faith healers, with their magic stones and astronomical mumbo-jumbo. Stonehenge's appeal was not religious. It answered to the simplest of human cravings, the relief of pain and the postponement of death. The Great Cursus points not to heaven but to Harley Street.

The stones, say the historians and archeologists, were all carved from nearby quarries, heaved up huge ramps and set in place by armies of workers. Some dissenters say that levers or pulleys were used, even though the wheel had not been invented at that time, the paper reported.

Until recently it was hard for geologists to distinguish between natural limestone and the kind that would have been made by reconstituting liquefied lime. But according to Professor Gilles Hug, of the French National Aerospace Research Agency (Onera), and Professor Michel Barsoum, of Drexel University in Philadelphia, the covering of the great Pyramids at Giza consists of two types of stone: one from the quarries and one man-made.

"There's no way around it. The chemistry is well and truly different," Professor Hug told Science et Vie magazine. Their study is being published this month in the Journal of the American Ceramic Society. The pair used X-rays, a plasma torch and electron microscopes to compare small fragments from pyramids with stone from the Toura and Maadi quarries. They found "traces of a rapid chemical reaction which did not allow natural crystalisation. The reaction would be inexplicable if the stones were quarried, but perfectly comprehensible if one accepts that they were cast like concrete."

The pair believe that the concrete method was used only for the stones on the higher levels of the Pyramids. There are some 2.5 million stone blocks on the Cheops Pyramid. The 10-tonne granite blocks at their heart were also natural, they say. The professors agree with the "Davidovits theory" that soft limestone was quarried on the damp south side of the Giza Plateau. This was then dissolved in large, Nile-fed pools until it became a watery slurry.

Lime from fireplace ash and salt were mixed in with it. The water evaporated, leaving a moist, clay-like mixture. This wet "concrete" would have been carried to the site and packed into wooden moulds where it would set hard in a few days. Davidovits and his team at the Geopolymer Institute at Saint-Quentin tested the method recently, producing a large block of concrete limestone in ten days.

The concrete theorists also point out differences in density of the pyramid stones, which have a higher mass near the bottom and bubbles near the top, like old-style cement blocks. Opponents of the theory dispute the scientific evidence. They also say that the diverse shapes of the stones show that moulds were not used. They add that a huge amount of limestone chalk and burnt wood would have been needed to make the concrete, while the Egyptians had the manpower to hoist all the natural stone they wanted, the paper said.

The chunk came from a meteorite that scored an arc of fire across the skies before slamming into Lake Tagish in British Columbia in 2000. It has been pored over by scientists ever since, and is today revealed to contain particles that predate the birth of our nearest star, the sun.

The Tagish Lake meteorite was already regarded as exceptional because its mineral composition linked it to the earliest days of the formation of the solar system, more than 4.5bn years ago. The fragments of meteorite that still exist are among the most pristine in the world, as they were protected from contamination when they became wedged in blocks of lake ice.

The latest research shows that peppered throughout the meteorite are grains that formed even earlier, in a frigid cloud of molecules, possibly at the edge of the swirling disc of dust that ultimately collapsed to form the sun and all the planets of the solar system.

The discovery suggests that while the first light from the sun fell on the fledgling Earth, as the dinosaurs rose and died out and humans gained dominance, the meteorite was hurtling around the heavens on a billions-of-years-long journey destined to terminate with a thud in Yukon territory.

Researchers at Nasa's Johnson Space Centre in Houston examined a two gram fragment of the meteorite and focused on tiny, hollow, carbon spheres embedded within it. Each "globule" measured just a few thousandths of a millimetre across.

Using electron microscopy and isotope tests, the scientists looked at the chemical make-up of the grains and discovered they had unusual ratios of different forms of nitrogen and hydrogen. Ratios of the isotope nitrogen-15 to nitrogen-14 were nearly twice those on Earth, while the ratio of deuterium, a heavy form of hydrogen, to normal hydrogen, was between 2.5 and nine times higher than usual.

Reporting in the journal Science today, a team lead by Keiko Nakamura-Messenger and Michael Zolensky show the levels of the isotopes in the meteorite could only arise from chemical reactions taking place in an extremely cold climate, where temperatures were as low as -260C. Those conditions would only be found in remote molecular clouds before the formation of the solar system, or at the very edge of what is known as the protosolar disc that was later to coalesce into the celestial bodies of the solar system. "These little particles within the meteorite seem to predate everything else. We don't know exactly how old they are, but they could be billions of years older than the rest of the meteorite," said Dr Zolensky.

Between 40,000 and 60,000 tonnes of meteorite matter is believed to land on Earth every year, and around 90% of this rains down steadily as fine particles that are rarely even identified.

Much of the material immediately disappears beneath the waves, and significant amounts are lost in the world's deserts and forests. Only a few tens of kilograms, in larger chunks, are usually recovered from any year's fallout.

Fragments of the Tagish Lake meteorite were recovered after locals spotted the fireball it created as it tore through the atmosphere at 20 miles per second. Large clumps of the meteorite were collected from the surface of the frozen lake, but other chunks were removed later embedded in blocks of ice, and transported to research labs. Around one tonne of fragments from the meteorite is now held in the Natural History Museum in London and at other sites in the US, Canada and Germany.

"These are the real time machines, the material that goes back to the earliest formation of the solar system," said Caroline Smith, meteorite curator at the Natural History Museum.

The meteorite is known as a carbonaceous chondrite and contains what many scientists regard as the building blocks for life: carbon, myriad clay minerals and even amino acids. Scientists say the clay layers, principally silicates, can form protective pockets around the organic chemicals and act as reaction chambers where more complex molecules can form. The possible role of these pockets in the ultimate emergence of life has lead some scientists to refer to them as "wombs".

"These things tell us what kind of chemicals are out there in interstellar space. They could have been the original seeds for life to get started," said Dr Zolensky.

The discovery was published in the Finnish astronomy magazine Tähdet ja avaruus ("Stars and Space") on Wednesday. Moilanen's article was written with the help of NASA meteor expert Peter Jenniskens, who is considered one of the world's leading authorities in the field.

The comet itself has not yet been pinpointed, but it is believed to have an orbit around the sun that is about 4,000 years long. It comes closest to Earth just inside this planet's orbit, and is considered one of the five most potentially dangerous comets for Earth in the long term.

Nevertheless, experts say that the likelihood of a collision with Earth in the coming millennia is vary small.

"It could be coming, or then the meteor shower could be material that it has left behind, such as dust or grains of sand. There is no sense in being too frightened by it", Moilanen says.

It was confirmed this autumn that the shower can be seen each year in October. The name that was proposed for the the event is the October Camelopardalis, because the meteor showers linked with the comet appear in the sky near the constellation Camelopardalis, or giraffe.