Two independent scientific teams have found what may be the first direct evidence of water ice on the surface of an asteroid, a discovery that lends support to the idea that asteroids could have helped deliver water to the early Earth.
Asteroids are generally considered to be rocky, and comets icy. That's because ice in the early solar system is thought to have formed beyond a "snow line" lying somewhere between Mars and Jupiter.
Asteroids forming beyond that boundary could contain ice.
But, it is not clear how common ice might be in the main asteroid belt, because sunlight is expected to quickly vaporise ice on the surfaces of airless bodies that fly closer to the sun than Jupiter.
In 2008, however, Andrew Rivkin of Johns Hopkins University in Laurel, Maryland, and Joshua Emery of the SETI Institute in Mountain View, California, found hints that the asteroid 24 Themis, which sits in the main asteroid belt between Mars and Jupiter, could have water ice on its surface.
Science & Technology
© Vladimir Rubtsov
The Tunguska Mystery
The Tunguska Mystery
In The Tunguska Mystery by Vladimir Rubtsov, the efforts put forth by generations of Russian scientists, technicians, and others are documented. What did they find? Was it a meteorite, as had first been thought? Was it an asteroid? Was it a comet? Some support the idea that this was not a "natural" event at all but one caused by the explosion of an alien spaceship trying to land on Earth. Is there any evidence for this? How did the Russian scientific and world community react to this theory?
The mystery has been very difficult to solve, but it is important - perhaps even urgent - to solve it. We live in a very violent universe, and we are extremely vulnerable to its vagaries. How can we prevent another "Tunguska" if we don't even know what it was? And next time, the event might not occur in a remote, barely inhabited region of Earth. It may take many thousands of lives and destroy whole cities.
An archaeologist has found ancient tool fragments and other artifacts at the site of a suburban New York sewer construction project.
The find was made around Peach Lake, in the Putnam County town of Southeast.
Archaeologist Michael Pappalardo says the artifacts also include pottery shards; a 2 1/2-inch blade; tips for arrows or darts; and stone flakes that show tools were made there.
It's believed the artifacts are about 1,000 years old. They're being donated to the Southeast Museum in Brewster.
The dig was required by state and federal historic preservation acts.
The find was made around Peach Lake, in the Putnam County town of Southeast.
Archaeologist Michael Pappalardo says the artifacts also include pottery shards; a 2 1/2-inch blade; tips for arrows or darts; and stone flakes that show tools were made there.
It's believed the artifacts are about 1,000 years old. They're being donated to the Southeast Museum in Brewster.
The dig was required by state and federal historic preservation acts.
© AP Photo/HO/Lumiere Technology
This undated photo provided by Lumiere Technology in Paris shows the site of the fingerprint on a painting that art experts believe they have identified as a new Leonardo da Vinci.
This undated photo provided by Lumiere Technology in Paris shows the site of the fingerprint on a painting that art experts believe they have identified as a new Leonardo da Vinci.
Peter Paul Biro, a Montreal-based forensic art expert, said that a fingerprint on what was presumed to be a 19th-century German drawing of a young woman has convinced art experts that it's actually a Leonardo.
Canadian-born art collector Peter Silverman bought "Profile of the Bella Principessa" at the Ganz gallery in New York on behalf of an anonymous Swiss collector in 2007 for about $19,000. New York art dealer Kate Ganz had owned it for about 11 years after buying it at auction for a similar price.
One London art dealer now says it could be worth more than $150 million. If experts are correct, it will be the first major work by Leonardo to be identified in 100 years.
Ganz doesn't believe it is.
© Vance Holliday
Sediments at the San Jon site, in eastern New Mexico, contained very low abundances of magnetic spherules said to be evidence of an impact.
Sediments at the San Jon site, in eastern New Mexico, contained very low abundances of magnetic spherules said to be evidence of an impact.
An independent study has cast more doubt on a controversial theory that a comet exploded over icy North America nearly 13,000 years ago, wiping out the Clovis people and many of the continent's large animals.
Archaeologists have examined sediments at seven Clovis-age sites across the United States, and did not find enough magnetic cosmic debris to confirm that an extraterrestrial impact happened at that time, says the report in the Proceedings of the National Academy of Sciences (PNAS). It is the latest of several studies unable to support aspects of the impact hypothesis.
In 2007, a team led by Californian researchers announced a theory that a comet or asteroid had exploded over the North American ice sheet, creating widespread fire and an atmospheric soot burst followed by a cooling period known as the Younger Dryas.
Sometime after this, the Clovis people, sophisticated large-animal hunters known for their spear points, mysteriously disappeared; the team linked their vanishing to the environmental effects of the proposed impact.
© Mark Witton/UP
The new 160-million-year-old pterosaur, named Darwinopterus in honor of the famed 19th-century naturalist, has emerged as an important middle specimen between early, long-tailed pterosaurs - also known as pterodactyls - and later short-tailed ones.
"We had always expected a gap-filler with typically intermediate features," David Unwin, of the University of Leicester's School of Museum Studies and a member of the research team that analyzed the fossils, said in a prepared statement. "Darwinopterus came as quite a shock to us." The new findings were published online today in the Proceedings of the Royal Society B.
© Christian Lichtenberg/Getty
Peculiar experiences
Peculiar experiences
What this 21-year-old had just experienced was an out-of-body experience, one of the most peculiar states of consciousness. It was probably triggered by his epilepsy (Journal of Neurology, Neurosurgery and Psychiatry, vol 57, p 838). "He didn't want to commit suicide," says Peter Brugger, the young man's neuropsychologist at University Hospital Zurich in Switzerland. "He jumped to find a match between body and self. He must have been having a seizure."
In the 15 years since that dramatic incident, Brugger and others have come a long way towards understanding out-of-body experiences. They have narrowed down the cause to malfunctions in a specific brain area and are now working out how these lead to the almost supernatural experience of leaving your own body and observing it from afar. They are also using out-of-body experiences to tackle a long-standing problem: how we create and maintain a sense of self.
Patrick McGovern had just emerged from the ancient burial chamber in one of the most extensively excavated archaeological sites in China when a local scientist presented him with what he calls "the real treasure."
It was a sealed bronze drinking vessel that resembled a teapot from 1200 B.C.
With liquid still inside.
"I just about dropped over - a liquid sample from 3,000 years ago," said McGovern, a researcher at the University of Pennsylvania.
It was a sealed bronze drinking vessel that resembled a teapot from 1200 B.C.
With liquid still inside.
"I just about dropped over - a liquid sample from 3,000 years ago," said McGovern, a researcher at the University of Pennsylvania.
© Unknown
La Hougue Bie has stood for 6,000 years
La Hougue Bie has stood for 6,000 years
Every spring and autumn crowds of people gather to watch the equinox from inside the chamber.
Archaeologists can make educated guesses about what went on there, but much is shrouded in mystery.
The name is Norse in origin, coming from hougue meaning man made and bie meaning Homestead.
A statue of Alexander the Great has been discovered in the Egyptian coastal city of Alexandria, Governor Adel Labib said on Wednesday 7/10/2009.
Archeologists have suggested the statue was of Alexander the Great and it was uncovered during excavations at el-Shalalat Park in the city, he said.
The discovery was made by a Greek mission working in the city.
Archeologists have suggested the statue was of Alexander the Great and it was uncovered during excavations at el-Shalalat Park in the city, he said.
The discovery was made by a Greek mission working in the city.
Comment: For a more in-depth view, read: The Younger Dryas Impact Event and the Cycles of Cosmic Catastrophes - Climate Scientists Awakening