sábado, 30 de junho de 2012

Oldest Impact Crater on Earth Discovered

The world's oldest meteorite crater —a giant impact zone more than 62 miles wide — has been found in Greenland, scientists say.

Scientists think it was formed 3 billion years ago by a meteorite 19 miles (30 kilometer) wide — which, if it hit Earth today, would wipe out all higher life. The crater is so wide that it would reach the edge of space 62 miles (100 km) above Earth if stood on end.

The crater was "discovered" at an office in Copenhagen by scientist Adam Garde as he pored over maps showing nickel and platinum abundance in the target region of West Greenland. Garde, a senior research scientist with the Geological Survey of Denmark and Greenland, saw a both simple and extreme explanation for several strange geological features in this region: an impact from a meteorite that may have contained valuable metals.

Fonte: Space.com

quarta-feira, 27 de junho de 2012

1969 meteorite yields material previously unknown to science

A new study of fragments of an ancient rock that fell to Earth in 1969 has yielded a new mineral. Dubbed 'panguite' the new mineral may hold secrets about the formation of our solar system.

A fireball that tears across the sky is not just a one-time skywatching event — it can reap scientific dividends long afterward. In fact, one that lit up Mexico's skies in 1969 scattered thousands of meteorite bits across the northern Mexico state of Chihuahua. And now, decades later, that meteorite, named Allende, has divulged a new mineral called panguite.
Panguite is believed to be among the oldest minerals in the solar system, which is about 4.5 billion years old. Panguite belongs to a class of refractory minerals that could have formed only under the extreme temperatures and conditions present in the infant solar system.
The name of the titanium dioxide mineral, which has been approved by the International Mineralogical Association, honors Pan Gu, said in Chinese mythology to be the first living being who created the world by separating yin from yang (forming the earth and sky). [Infographic: The Science of Meteorites]
"Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science," study researcher Chi Ma, a senior scientist at Caltech, said in a statement.
Until now, panguite had neither been seen in nature nor created in a lab. "It's brand-new to science," Ma told LiveScience in an interview.
'Panguite is an especially exciting discovery since it is not only a new mineral, but also a material previously unknown to science.'
- study researcher Chi Ma
The scientists used a scanning-electron microscope to view the panguite within a so-called ultra-refractory inclusion embedded within the meteorite. Inclusions are the minerals that get trapped inside meteorites as they are forming. The ultra-refractory type includes minerals that can resist high temperatures and other conditions in extreme environments, such as those thought to exist as our solar system was forming.
High-tech lab analyses revealed panguite's chemical composition and crystal structure, which Ma said is new, and as such, could be explored for novel engineering materials.
The Allende meteorite, where the mineral was hidden, is the largest of a class of carbonaceous chondrites found on Earth. Chondrites are primitive meteorites that scientists think were remnants shed from the original building blocks of planets. Most meteorites found on Earth fit into this group. (When meteors hit the ground they are called meteorites.)
Before they reach terra firma, most meteorites are fragments of asteroids (space rocks that travel through the solar system), while others are mere cosmic dust shed by comets. Rare meteorites are impact debris from the surfaces of the moon and Mars. The Allende meteorite likely came from the asteroid belt between Mars and Jupiter, scientists say.
Studying panguite and other components of the Allende meteorite are essential for understanding the origins of the solar system, Ma said. In fact, Ma's team has discovered nine new minerals, including panguite, in the Allende space rock.
The new mineral is detailed in the July issue of the journal American Mineralogist.

Fonte: Foxnews.com

terça-feira, 26 de junho de 2012

Martian meteorite to go on display from tomorrow in Vienna

The Natural History Museum in Vienna (NHM) is celebrating a spectacular new acquisition after spending almost half a million to acquire a rare martian meteorite from a private collector.

Martian meteorites differ from regular meteorites in that they were originally part of the red planet – but were jettisoned into space by the impact of another meteorite. These tiny fragments blasted into the martian atmosphere and then into space eventually ended up being trapped in earth's gravity and pulled down to the ground.

The meteorite acquired by the Natural History Museum has already attracted a lot of interest and has been named the "Tissint" meteorite.

It weighs about a kilo and will go on display in Saal V from tomorrow (Wed) – and then will be moved to its new permanent home in the renovated meteorite rooms of the museum in November.

Museum director Christian Köberl said they had learnt that they could make a bid in December and discovered in February that their offer had been accepted.

The museum has the world's oldest meteorite collection which was started in 1748. One of the original meteorites that founded the collection was the so-called Hraschina meteorite that fell to Earth in 1751 landing at Zagreb in Croatia.

Of over 53,000 meteorites that have been found on Earth, 99 were identified as martian. These meteorites are thought to be from Mars because they have elemental and isotopic compositions that are similar to rocks and atmosphere gases analyzed by spacecraft on Mars.

Fonte: Austrianindependent.com

segunda-feira, 25 de junho de 2012

If aliens were found how would it influence religious beliefs

The discovery of life beyond Earth would shake up our view of humanity's place in the universe, but it probably wouldn't seriously threaten organized religion, experts say.

Religious faith remains strong in much of the world despite scientific advances showing that Earth is not the center of the universe, and that our planet's organisms were not created in their present form but rather evolved over billions of years. So it's likely that religion would also weather any storms caused by the detection of E.T., researchers say.

"I think there are reasons that we might initially think there are going to be some problems," said Doug Vakoch, director of Interstellar Message Composition at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif. "My own hunch is they're probably not going to be as severe as we might initially think."

Vakoch spoke Sunday (June 24) at the SETICon 2 conference, in a panel discussion called "Would Discovering ET Destroy Earth's Religions?" [5 Bold Claims of Alien Life]

We're not the center of the universe

The Bible, Koran and other sacred texts of the world's major religions stress God's special concern for humanity and for Earth. So the discovery of aliens — microbes on Mars, say, or signals from an intelligent civilization in another solar system — might seem threatening, by implying that we and our planet aren't all that special.

But our species has had plenty of time to get used to this idea. Nicolaus Copernicus made perhaps the first powerful case for it in 1543, when his seminal work "On the Revolutions of the Celestial Spheres" showed that Earth revolves around the sun, rather than the other way around.

"We haven't been the center of the universe for a while now — four centuries," said panelist Seth Shostak, a senior astronomer at the SETI Institute.

And recent alien planet discoveries continue to remind us of this fact. Scientists have already detected more than 700 planets beyond our solar system, and several thousand more await confirmation by follow-up observations. Some of these exoplanets are small and rocky, like Earth, and some orbit in their stars' habitable zone, that just-right range of distances where liquid water could exist on the planet.

We also have a few historical test runs that shed light on how people might react if we ever do discover E.T., Shostak added.

In the early 20th century, for example, many people regarded the so-called "canals" of Mars as strong evidence of an intelligent civilization on the Red Planet. And in the mid-1990s, scientists announced the discovery of possible microfossils in the Martian meteorite known as ALH 84001.

In neither case did the walls of churches, mosques and temples start to crumble.

"This experiment's been run many times, and people never go nuts," Shostak said. (The debate over ALH 84001 continues today, but most Mars scientists remain unconvinced that it contains strong indications of life.)

God's other children?

Further, the news that we're not alone in the universe likely wouldn't come as a huge shock, because large numbers of people in the United States and abroad already believe that E.T. is out there somewhere.

"If you ask most people whether there is alien life, most people say yes," said science-fiction author Robert Sawyer, who was also part of the panel discussion. "It's the prevalent opinion. At least, the last poll I saw in the United States was that most Americans believe that there's extraterrestrial life."

So rather than being shaken to its foundations by the confirmation of life on another planet or moon, organized religion may accept the news, adapt and move on.

Vakoch cited the example of Baptist theologian Hal Ostrander, who is an associate pastor at a church in Georgia.

"Dr. Ostrander is adamantly opposed to evolution, and yet he has no problem with the idea of there being extraterrestrials," Vakoch said. "He says it's as if a couple has one child, and then they decide to have a second child. Is that second child any less special? So too if God decides to have life on our planet, and then another planet, and another planet. It doesn't make us less special."

Fonte: today.msnbc.msn.com

quarta-feira, 20 de junho de 2012

Market for Martian Meteorites Heats Up

No mission to Mars has ever brought back rocks, but pieces of the Red Planet have turned up on Earth.

In late May, a Mars rock, small enough to fit easily into in an adult’s palm and covered in a glossy crust as black as space, sold for $43,750, a significant price, even for a piece of the fourth planet.

"It should be stated that Mars is among the rarest things on Earth," said Darryl Pitt, the dealer who sold this specimen at auction. [Latest Mars

This rock was a piece of the Tissint meteorite, which appeared as a fireball in the sky over the desert southwest of Tissint, Morocco, on July 18, 2011. Local people discovered the pieces of the Tissint meteorite in November, and a team of experts classified it, making the discovery official in January.

Tony Irving, a meteoriticist at the University of Washington, estimates the Tissint meteorite brought at least 33 pounds (15 kilograms) of Mars rock to Earth.

"It is going to be very hard to get an accurate tally because so many people have gotten involved," Irving said.

After its discovery, pieces of the Tissint entered a growing commercial market for meteorites. Demand, and prices, for meteorites increased dramatically as a result of publicity surrounding the first public auctions offering meteorites in the late 1990s, according to Pitt. The demand has, in turn, motivated meteorite hunters to find more of them.

Now a year after it fell, Tissint pieces have been snapped up by collectors and institutions, but some of it is still up for sale.

Pitt estimates about 5 pounds (2.3 kilograms) are still on the market, including the largest chunk or "main mass" that weighs 2.8 pounds (1.3 kg), for which he is seeking a buyer. Pitt also plans to sell another, smaller fragment at a meteorites-only auction offered by Heritage Auctions in October.

A natural history favorite

This smaller fragment, a 1.6-ounce (46-gram) coal-colored rock, was among a selection of meteorites that Heritage Auction offered for sale on May 20. Its company included a small slice of giant iron meteorite discovered in 1902 in Willamette, Ore., that is on display at the American Museum of Natural History; slices of meteorites from the moon; and pieces of pallasite meteorites dotted with the gem peridot, the August birthstone.

At a media preview before the May 20 auction, the museum's director, David Herskowitz, showed off the meteorites.

"For everyone who has every worldly possession, he can actually own something from out of this world," Herskowitz said. "Meteorites are the most popular, the most highly collectible of all natural history [items]. There are more people that collect meteorites than there are that collect fossils, dinosaurs, even minerals." [Up For Auction: A Natural History Gallery]

Meteoritic miracles

A meteorite is a chunk of stone or metal from space that lands on the planet's surface. Most meteorites originate from the asteroid belt between Mars and Jupiter, when collisions fling out bits of asteroid, which eventually find their way into Earth's gravitational field

These must then survive the journey through Earth's atmosphere before striking the ground. If humanity is ever to recover them, the meteorites must land somewhere they can be found.

"I find almost every meteorite fall miraculous," said Geoffrey Notkin, a writer, meteorite dealer and host of the Science Channel's "Meteorite Men."

Meteorites ejected from the moon and Mars by asteroid collisions are rarer. About 65 Martian meteorites, including Tissint, have been recovered, Irving estimates.

A question of interest

Collectors are interested in more than just a meteorite's origin, Notkin said. For instance, beautiful specimens — think of sparkling specks of yellow peridot gems or the way iron meteorites resemble abstract sculptures — fetch higher prices, as do those with back stories, such a history that includes being traded out of a famous museum collection. Over time, meteorite prices have been increasing, partly due to inflation, partly due to increased interest, Notkin said.

The nearly $1,000 per gram cost of the Tissint specimen sold on May 20 is fairly typical for a high-quality Martian meteorite, he said.

The commercial meteorite market isn't limited to the meteorites themselves. Items struck by meteorites — a Chevy Malibu and a mailbox, for instance, have also sold for handsome prices.

A Martian origin

While missions to the moon have returned with lunar rocks, no Mars rocks have been brought back. So, why do scientists think meteorites like Tissint came from Mars?

In roughly 10 of the Martian meteorites, researchers have studied the composition of pockets of gas trapped in veins of melted rock formed by the shock of the ejection, and matched it to the composition of the Martian atmosphere. The remaining Martian meteorites have chemical features similar to those found to contain gas matching Mars' air.

Tissint appears to be one of a group of Martian meteorites, approximately 10 in all, that likely have been ejected from Mars 1.1 million years ago. All, however, have arrived on Earth at different times, the first landing 400,000 years ago.

Discoveries of meteorites, including those from Mars, are increasing; well over half of Martian meteorites have turned up since 2000.

Meteorites are most easily found in deserts, both icy and rocky ones. Expeditions to Antarctica have contributed to the increase in finds, as has the emergence of a meteorite-prospecting enterprise in northwestern Africa, including Morocco, where nomads and others search the desert for valuable rocks.

"It must be concluded that future discoveries elsewhere are limited mainly by insufficient effort. Let's get going!" Irving writes on his website.

Fonte: livescience.com

quinta-feira, 14 de junho de 2012

You Can Thank A Meteorite For The Red Color Of Tomatoes

More than 60 million years ago, a meteorite slammed into Earth, wiping out the dinosaurs, and, on a less morbid note, giving tomatoes their distinct red color. 

According new research published in Nature, the crash and resulting solar eclipse created extremely stressful conditions.

As a method of survival, a distant relative of the crop grew three times in size, while producing the fleshy red fruit we enjoy in salads and mozzarella sandwiches today.

So it all worked out! Well, except for the dinosaurs.

Fonte: Businessinsider.com

terça-feira, 12 de junho de 2012

Meteorite storm 'smashed the Earth 12,000 years ago and killed off a prehistoric people'

Scientists find 'melt-glass' in 12,000-year-old rock
Melt glass forms at 1,700 degrees - equal to atomic bomb
Meteorites thought to have triggered a cold snap that killed off early civilisation and giant animals

Scientists have found compelling evidence that a meteorite storm hit the earth more than 12,000 years ago, and is likely to have been responsible for the extinction of a prehistoric people and giant animals including mammoths.

Evidence of the meteorite’s intense heat was found on two continents. The researchers believe the huge cosmic impact triggered a vicious cold snap, which caused widespread destruction.

The international team found a substance known as melt glass, which forms at temperatures of 1,7000 to 2,200 degrees Celcius and can result from a ‘cosmic body’ hitting the earth.

Extreme heat: The meteorite impact caused the 13,000-year-old quartz found in Syria to melt and boil, creating features including burst bubbles and flow textures

The material was found in a thin layer of rock in Pennsylvania and South Carolina in the US, along with Syria. Tests confirmed the material was not of cosmic, volcanic or human-made origin.


Police inundated by terrified callers as meteor lights up the sky across Britain

'Mega meteor that crashed off Indian coast' may have wiped out dinosaurs

‘The extreme temperatures required are equal to those of an atomic bomb blast, high enough to make sand melt and boil,’ said James Kennett, professor of earth science at UC Santa Barbara.

The melt-glass appears identical to other material found in Meteor Crater in Arizona, and the Australasian tektite field, and also matches melt-glass produced by the 1945 Trinity nuclear airburst in New Mexico in the US, Professor Kennett said.

Gone forever: The meteor storm is thought to have caused the mass extinction of megafauna including the woolly mammoth
The team's findings support the controversial theory that an asteroid impact occurred 12,900 years ago and triggered the start of an unusual cold period on Earth, leading to widespread extinction of human and animal life.
In the cold period, known as the Younger Dryas, North American megafauna including mammoths and giant ground sloths disappeared forever, along with a prehistoric civilisation called the Clovis culture.
The Clovis people used distinctive bone and ivory tools and are regarded as the first human inhabitants of the New World.

Match: Melt glass, known as trinitite, formed during the Trinity nuclear airburst in New Mexico in 1945 when rocks melted. The scientists say the melt-glass is similar to that found in the 12,800-year-old rock
Evidence supporting the theory has now been found on three continents, covering nearly one-third of the planet, from California to Western Europe, and into the Middle East.
Syria is the easternmost site yet identified in the northern hemisphere, but the researchers have yet to find a limit to debris field of the impact. Melt-glass has been found in rock layers of the same age in Arizona and Venezuela.

Scientists found the melt glass - evidence of the meteorite's intense heat - in Pennsylvania and South Carolina in the US along with Syria

The three sites found in the latest study were separated by 1,000 to 10,000 kilometers, suggesting that ‘a swarm of cosmic objects,’ either fragments of a meteorite or comet, had hit the earth, Professor Kennett said.

Proof: Earth scientist James Kennett says evidence for the meteorite has been found over one third of the planet----------------->>>>>

Professor Kennett added that the archaeological site in Syria where the melt-glass material was found –– Abu Hureyra, in the Euphrates Valley –– is one of the few sites of its kind that record the transition from nomadic hunter-gatherers to farmer-hunters who live in permanent villages.

‘Archeologists and anthropologists consider this area the “birthplace of agriculture,” which occurred close to 12,900 years ago,’ Professor Kennett said.

‘The presence of a thick charcoal layer in the ancient village in Syria indicates a major fire associated with the melt-glass and impact spherules 12,900 years ago,’ he continued.

‘Evidence suggests that the effects on that settlement and its inhabitants would have been severe.’

The study was published today in the Proceedings of the National Academy of Sciences.

Fonte: Dailymail.co.uk

domingo, 10 de junho de 2012

The black market for meteorites

Meteors are ethereal and heavenly as they zip across the night sky—but what happens when they fall to Earth is something else entirely. Writing at the website of the excellent BBC Radio program “The Naked Scientists,” Audrey Tempelsman looks at the global trade in meteorites, and finds a shadowy, globe-spanning gray market.

The price for a meteorite can reach $1,000 per gram, and the laws governing their ownership are as varied as the countries where they land. “If a meteorite crash-lands into your rental home in the U.S. or U.K.,” Tempelsman explains, “it’s considered the landlord’s property. If you stumble upon a space rock in Japan, however, finders-keepers applies.” In other countries, meteorites must be handed over to government-run museums.

Many meteorite resellers, Tempelsman writes, close their eyes to the legal aspects of the merchandise. As Ralph Harvey, a geologist at Case Western Reserve University, tells Tempelsman,“The skill level that some collectors have to get stones out of Africa rivals that of drug dealers.” Scientists and museums can find themselves negotiating with multiple dealers, each selling a fragment of the same rock; often, they must raise money to outbid deep-pocketed private collectors. It’s a very worldly process in pursuit of an otherworldly object.

Fonte: Boston Globe

segunda-feira, 4 de junho de 2012

Inside the International Meteorite Market

Writing at The Naked Scientists, Amy Tempelsman offers up an overview of the market in meteorites. Apparently, when a meteorite falls to earth, it sets off a "feeding frenzy": According to Ralph Harvey, a geologist at Case Western Reserve University, "There is a market out there that treats these [meteorites] as collectibles and curios, almost as though they were fine art or ancient artifacts," and scientists and museums must negotiate a bewildering network of middlemen to obtain a meteorite.

Twelker purchases meteorites from dealers in Morocco, Russia, Canada and Nigeria, among other countries. When asked how he determines the legality of the specimens he purchases, Twelker paused. “There’s some degree of concern,” he said. “To a large extent -- and I would say this is for dealers and institutions, as well -- the question [of legality] isn’t asked or it isn’t pursued.”.... Making sure that meteorites are acquired legally has proven particularly difficult in North Africa, where it’s often difficult to determine the provenance of specimens for sale. “The skill level that some collectors have to get stones out of Africa rivals that of drug dealers,” says Dr. Harvey. “It’s clear that meteorites are so valuable to these collectors that they’re more than happy to get them and worry about the cost in terms of legality later on."

It's not all cloak-and-dagger, though -- the laws governing meteorite finds are also just plain confusing:

Every country has its own way of determining meteorite ownership -- that is, if such laws exist at all. If a meteorite crash-lands into your rental home in the U.S. or U.K., it’s considered the landlord’s property. If you stumble upon a space rock in Japan, however, finders-keepers applies. In Switzerland, meteorites belong to the government -- but the finder is compensated with a sum suitable to the value of the object. In India, Denmark, and most Australian states, meteorites must be handed over to specific, government-owned museums.

Typical price for a Martian meteorite: about $1,000 per gram.

Fonte: Boston.com

sábado, 2 de junho de 2012

Meteorite fragment donated to UCD prof

UC Davis alumnus Gregory Jorgensen presented UC Davis geologist Qing-Zhu Yin with a donation Wednesday, of a meteorite piece that fell beside his driveway.
The meteorite, a rare carbonaceous chondrite, contains the dust and grains that helped form the Earth and other planets more than four and a half billion years ago.

Yin calls it "invaluable" to science and has asked others to come forth with donations. His lab is one of the few in the nation with the equipment needed to analyze and date the meteorite.

Jorgensen is a chemistry professor at American River College in Sacramento. His donation is one of two meteorite pieces he stumbled upon. The first was found while taking a casual walk with his wife, Alice, and 7-month-old daughter, Abriela at Marshall Gold Discovery State Historic Park in Coloma.

Jorgensen hadn't heard the fireball that indicated the meteorite's fall on April 22, and his wife was in Los Angeles at the time. When they saw people at the park looking for something on the ground, they thought they were mushroom hunters. Then they learned of the meteorite.

"When we got back to the car, I looked down and saw a rock that looked a little different," said Jorgensen. "I put it in my pocket. Over the course of the days, I figured out it was a meteorite."

Fonte: dailydemocrat.com