Tissint meteorite helps build Museum Martian library

 Museum scientist Natasha Stephen gets ready to analyse a tiny sample of the Tissint Martian meteorite. © Diamond Light Source


It may sound like a place where Martians sit and read books, but the Natural History Museum's Martian library is in fact a database of Martian meteorites, which has had a huge boost with the arrival of the Tissint meteorite.


Rare meteorites

Meteorites from Mars are incredibly rare - there are only 65 known in the world. The Tissint Martian meteorite fell to Earth in Morocco last July.

Crucially, it landed in the dry conditions of a desert and was picked up soon afterwards, so scientists think its contamination levels are likely to be much lower than other meteorites, making it even more valuable than others.

Terrestrial rocks
Up until now, most Martian research has been done by studying non-Martian meteorites and rocks from Earth (terrestrial rocks).


The planet Mars. It's our closest neighbour and many of its rocks are similar to Earth's.
This is because no samples have been collected directly from Mars - it would be too expensive and Mars is too far away. Only electronic data is sent back.

Although they are non-Martian, terrestrial rocks are still very useful because Mars has canyons and once had active volcanoes, meaning many of its rocks are similar to Earth's.

And now Museum scientist Natasha Stephen and colleagues can add data from the important Tissint specimen to the Museum's Martian meteorite library.

Natasha says, 'Tissint provides us with a rare and exciting opportunity to study a potentially very fresh piece of the Martian surface, something that is invaluable to planetary scientists until we have an actual sample collected from Mars'.

Meteorite composition 

3D map of Infra Red data from the Tissint Martian meteorite, taken at Diamond Light Source.
Natasha is investigating the mineral and geochemical composition of Martian meteorites. As part of this, she is collecting Fourier Transform Infra Red (FTIR) spectral measurements, using state-of-the art analytical facilities at the Museum and at the Diamond Light Source in Oxfordshire, UK.

The FTIR readings give unique 'signatures' for each of the minerals in the rocks. These can identify what type of rock it is, and suggest where on Mars it may be from. This will be the first ever Martian-specific mineral database of IR data.

'Adding data from Tissint to our library gives a more complete view of the composition of these rocks and how weathering and alteration can affect them.

'Using "fresh" data alongside previous studies should allow for a more accurate interpretation of remotely acquired data without the need for any scientist to actually stand on the Martian surface, a feat that is still many years away from us.'

How do we know a meteorite is from Mars?

Martian meteorite named Los Angeles. Natasha Stephen is investigating the composition of different meteorite minerals, shown here with false colours.
The main way scientists know a meteorite is from Mars is by looking at the trapped gases in glass pockets inside a meteorite, which match almost exactly the composition of Mars' atmosphere. 'We know the composition of Mars' atmosphere from data collected by NASA Viking missions in the 1970s,' explains Natasha.

Another way to identify a Martian meteorite is to analyse its oxygen isotopes - they are specific to regions of the solar system so each has its own 'signature'. Oxygen isotopes from Mars have a unique Martian signature.

'Martian meteorites are also typically younger than other stony meteorites,' says Natasha. 'They have travelled a shorter distance since ejection off the host’s surface'.

Why is it important to understand Mars?

Mars is our closest neighbour and many of its rocks are similar to Earth's. It once had active volcanoes but at some point Mars stopped being geologically active. Scientists would like to know why, and whether this could be the future for Earth.

Also, we know that there was water on Mars and inactive volcanoes show there was once energy. Water and energy are two necessities for life. So, was there ever life on Mars? Or could there be in the future?

With Tissint and other Martian meteorites such as the 13 looked after at the Museum, as well as NASA's Curiosity rover that lands on the surface of Mars a week from today, scientists will be able to get much closer to answering these questions.



Fonte: Natural History Museum

Launton meteorite at Tate Britain

The meteorite fell into a labourer's garden in Oxfordshire on 15 February 1830

A meteorite that fell to earth in an Oxfordshire village in 1830 is being displayed at Tate Britain.

The cricket-ball sized rock is part of an exhibition by the Oxford-based artist and filmmaker Patrick Keiller.

His installation called The Robinson Institute represents the work of a fictional researcher called Robinson.

Through a series of objects found on his travels, Keiller's work examines the development of global capitalism.

There are two meteorites in the exhibition, one fell in 1795 in Yorkshire and the other is the Launton meteorite which fell near the Oxfordshire village 35 years later - both years of major historical events accord to Mr Keiller.

He said: "1830 was a year of revolutions not just at Otmoor [where the meteorite was found] but also in France and Belgium.

"The first city-to-city passenger railway ran in 1830 and the book Principals of Geology was published in 1830, so it's a kind of key year."

'Three ordinary guns'
According to Oxford University astronomer, Dr Rob Simpson, meteorite falls of this size are rare events. In Britain there are thought to be a handful every century.

He said slightly bigger meteorites that could destroy a village occur globally every 100 years and ones that can create kilometre-sized creators are thought to occur every 1,000 but we have not had one for over 50,000.

No one has ever recorded a human death as a result of a fall but a dog was reputedly killed by the Nakhla Martian meteorite in Egypt in 1911.

The Launton meteorite is normally kept at the Natural History Museum in London as part of its scientific research collection but went on display in the Tate in March.

Its fall on 15 February 1830 was described in an account written by a doctor from Buckingham called Mr Stowe.

In the Magazine of Natural History, 1831 he wrote: "Its descent was accompanied with a most brilliant light, which was visible for many miles around, and attended with a triple explosion, which was described to me, by a person who heard it at the distance of four miles, as resembling the rapid discharge of three ordinary guns."

Patrick Keiller: The Robinson Institute is at Tate Britain 27 March - 14 October and is free to attend.


Fonte: BBC News

Meteorite crater discovered in Arctic

Keith Dewing, of the Geological Survey of Canada, stands on a met­eorite crater’s edge on the northwest of Victoria Island, in Northwest Territories in July 2010, after researchers discovered evidence of the crater from helicopter. (CP)

 Canadian researchers say they’ve discovered a 25-kilometre-wide meteorite crater in the western Arctic while they were updating maps.

University of Saskatchewan professor Brian Pratt and Keith Dewing of the Geological Survey of Canada made the discovery while exploring Victoria Island in a helicopter two years ago.

At the time, they were doing map work for a Natural Resources Canada energy and minerals program.

“It was one of the few parts of the Arctic that hasn’t been mapped in real detail. There was a map done in the 1960s but it was a very general map so we were going in to make it a more detailed map,” said Pratt.

“The chances of finding a new meteorite impact are a once-in-a-lifetime thing. So you can imagine that we were absolutely thrilled that we were the lucky ones.”

They say it took two years to properly confirm that it was a meteorite crater. They’ve produced a paper on the discovery that will now be open to peer review.

Pratt and Dewing say the crater is at least 130 million years old and could even be as old as 350 million years. They’ve named the new discovery the Prince Albert impact crater, after the name of the peninsula where it is located.

Pratt says it’s certainly a big crater, although it’s not the biggest.

According to the Geological Survey of Canada’s Earth Impact Database, operated by the University of New Brunswick, one of the largest meteorite craters in Canada is at Sudbury, Ont., at approximately 130 kilometres across. The database lists a crater in Chicxulub, Mexico, as one of the largest in the world at 150 kilometres across.

Beverly Elliott, data manager at the centre, says the Chicxulub crater is the one that’s thought to have wiped out the dinosaurs.

Elliott said the new crater on Victoria Island is still just a claim at this point as far as the centre is concerned. Peer review is still required before it gets on their list, she said, and it must also meet a certain number of other criteria.

“As soon as that publication comes out, we’ll have a look at it,” said Elliott, speaking from Fredericton.

There are at least 160 known meteorite features on Earth.


Fonte: http://thechronicleherald.ca/canada

Universal debris falls onto Al-Shifa Mountain near Al-Ajbel Village in KSA

The deputy chairman of the Astronomy Society in Jeddah and member of the Arab Federation for Space Science and Astrophysics, astrophysicist. Sharaf al-Sufiyani revealed that meteorite debris fell on Al-Shifa mountain last Sunday near the village of Al-Ajbel.


He pointed out in his statement to the daily Medina newspaper today that the meteorite debris comprises large rocky pieces which before landing disintegrated into smaller pieces and landed on various locations. One of the dwellers told him that there are two other locations similar debris has fallen.

Regarding the timing of the meteorite's falling, Al-Sufiyani said that it would be too difficult to determine the exact timing which requires specialized laboratories, but it looks not too old because parts of the debris are still scattered on the surface and if it is old then it would have been buried under the ground and would have been too difficult to find.

He also said that should this meteorite have fallen on a house or heavily populated region it would have inflicted gross damage.

However, thanks to divine providence , our planet earth is surrounded by an atmospheric layer which prevents the landing of lots of meteorite debris onto mother earth otherwise it would have caused a great disaster that is many folds of its weight.

Meteorites are universal rocky formations orbiting outer space and whenever these pass through the stratosphere the earth attracts them and so they fall onto earth. Such meteorites burnout as a result of friction against air and if burned before arrival onto earth, scientists call them meteorites however should they land on earth they are called universal debris. (IY)


Fonte: Bahrain News Agency

Ancient meteorites shed light on Earth’s birth

 Scientists are studying meteorites to understand Earth’s earliest history--its formation from Solar System material into the present-day layering of metal core and mantle, and crust. 

New research from a team including Carnegie’s Doug Rumble and Liping Qin focuses on one particularly old type of meteorite called diogenites. 

These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the Solar System’s earliest chemical processing. 


At some point after terrestrial planets or large bodies accreted from surrounding Solar System material, they differentiate into a metallic core, asilicate mantle, and a crust. This involved a great deal of heating. The sources of this heat are the decay of short-lived radioisotopes, the energy conversion that occurs when dense metals are physically separated from lighter silicate, and the impact of large objects. 

Studies indicate that the Earth’s and Moon’s mantles may have formed more than 4.4 billion years ago, and Mars’s more than 4.5 billion years ago. 

Theoretically, when a planet or large body differentiates enough to form a core, certain elements including osmium, iridium, ruthenium, platinum, palladium, and rhenium—known as highly siderophile elements—are segregated into the core. 

But studies show that mantles of the Earth, Moon and Mars contain more of these elements than they should. Scientists have several theories about why this is the case and the research team—which included lead author James Day of Scripps Institution of Oceanography and Richard Walker of the University of Maryland—set out to explore these theories by looking at diogenite meteorites. 

Diogenites are a kind of meteorite that may have come from the asteroid Vesta, or a similar body. They represent some of the Solar System’s oldest existing examples of heat-related chemical processing. What’s more, Vesta or their other parent bodies were large enough to have undergone a similar degree of differentiation to Earth, thus forming a kind of scale model of a terrestrial planet.

The team examined seven diogenites from Antarctica and two that landed in the African desert. They were able to confirm that these samples came from no fewer than two parent bodies and that the crystallization of their minerals occurred about 4.6 billion years ago, only 2 million years after condensation of the oldest solids in the Solar System. 

Examination of the samples determined that the highly siderophile elements present in the diogenite meteorites were present during formation of the rocks, which could only occur if late addition or ‘accretion’ of these elements after core formation had taken place. This timing of late accretion is earlier than previously thought, and much earlier than similar processes are thought to have occurred on Earth, Mars, or the Moon. 

Remarkably, these results demonstrate that accretion, core formation, primary differentiation, and late accretion were all accomplished in just over 2 to 3 million years on some parent bodies. In the case of Earth, there followed crust formation, the development of an atmosphere, and plate tectonics, among other geologic processes, so the evidence for this early period is no longer preserved. 

“This new understanding of diogenites gives us a better picture of the earliest days of our Solar System and will help us understand the Earth’s birth and infancy,” Rumble said. 

“Clearly we can now see that early events in planetary formation set the stage very quickly for protracted subsequent histories,” he added. 

Their work has been just published online by Nature Geoscience. 




Fonte: zeenews.india.com

New clues to the early Solar System from ancient meteorites

In order to understand Earth's earliest history--its formation from Solar System material into the present-day layering of metal core and mantle, and crust--scientists look to meteorites. New research from a team including Carnegie's Doug Rumble and Liping Qin focuses on one particularly old type of meteorite called diogenites. These samples were examined using an array of techniques, including precise analysis of certain elements for important clues to some of the Solar System's earliest chemical processing. Their work is published online July 22 by Nature Geoscience.


At some point after terrestrial planets or large bodies accreted from surrounding Solar System material, they differentiate into a metallic core, asilicate mantle, and a crust. This involved a great deal of heating. The sources of this heat are the decay of short-lived radioisotopes, the energy conversion that occurs when dense metals are physically separated from lighter silicate, and the impact of large objects. Studies indicate that the Earth's and Moon's mantles may have formed more than 4.4 billion years ago, and Mars's more than 4.5 billion years ago. Theoretically, when a planet or large body differentiates enough to form a core, certain elements including osmium, iridium, ruthenium, platinum, palladium, and rhenium—known as highly siderophile elements—are segregated into the core. But studies show that mantles of the Earth, Moon and Mars contain more of these elements than they should. Scientists have several theories about why this is the case and the research team—which included lead author James Day of Scripps Institution of Oceanography and Richard Walker of the University of Maryland—set out to explore these theories by looking at diogenite meteorites. Diogenites are a kind of meteorite that may have come from the asteroid Vesta, or a similar body. They represent some of the Solar System's oldest existing examples of heat-related chemical processing. What's more, Vesta or their other parent bodies were large enough to have undergone a similar degree of differentiation to Earth, thus forming a kind of scale model of a terrestrial planet. The team examined seven diogenites from Antarctica and two that landed in the African desert. They were able to confirm that these samples came from no fewer than two parent bodies and that the crystallization of their minerals occurred about 4.6 billion years ago, only 2 million years after condensation of the oldest solids in the Solar System. Examination of the samples determined that the highly siderophile elements present in the diogenite meteorites were present during formation of the rocks, which could only occur if late addition or 'accretion' of these elements after core formation had taken place. This timing of late accretion is earlier than previously thought, and much earlier than similar processes are thought to have occurred on Earth, Mars, or the Moon. Remarkably, these results demonstrate that accretion, core formation, primary differentiation, and late accretion were all accomplished in just over 2 to 3 million years on some parent bodies. In the case of Earth, there followed crust formation, the development of an atmosphere, and plate tectonics, among other geologic processes, so the evidence for this early period is no longer preserved. "This new understanding of diogenites gives us a better picture of the earliest days of our Solar System and will help us understand the Earth's birth and infancy," Rumble said. "Clearly we can now see that early events in planetary formation set the stage very quickly for protracted subsequent histories."

Fonte: Phys.org

New answers found to Tunguska meteorite mystery

The mysterious explosion that occurred in the early morning on June 30, 1908 near the Stony Tunguska River, has been haunting the researchers for over a hundred years. Recently, a group of experts from the University of Bologna found a strange anomaly in the center of Lake Cheko, located eight kilometers from the epicenter of the explosion that may be a fragment of a celestial body.

Tunguska is the common name of the three major tributaries of the Yenisei: The Upper (Angara), Medium (Stony) and Lower. In the area near the village of Stony Tunguska near the village of Vanavara on June 30, 1908 around 7:00 am a big fireball was seen, overflying the territory of the Yenisei River basin from the southeast to the northwest (on an alternative testimony, the body was cylindrical in shape). The flight ended with a deafening booming explosion over the taiga at seven to ten kilometers above the ground.

A powerful blast wave was recorded by observatories around the world. A flash of light was observed at a great distance - the ball has become a pillar of fire at about 20 kilometers altitude. On the territory of more than two thousand kilometers trees were knocked down and in houses, located hundreds of kilometers from the epicenter of the explosion, windows were blown out.


Ironically, within 13 years no one dared to carry out studies on the site of the explosion. Only in 1921, a romantic enthusiast, a member of the Mineralogical Museum in Moscow, Leonid A. Kulik, accidentally learned about the Tunguska mystery from an old sheet tear-off calendar, and his interest was sparked. With the support of Academicians Vernadsky and Fersman, he organized the first expedition to the area of ​​Stony Tunguska.

Kulik and his companions gathered over 230 fragments weighing over 200 pounds. But these were the fragments of meteorites that fell earlier in the taiga. In addition, the expedition found microscopic silicate and magnetite pellets and fragments of rock with a high content of elements, indicating a possible cosmic origin of the substance. However, it has not been established whether they were remnants of the above events.

Today there are about 120 scientific, pseudo-scientific and pseudoscientific hypotheses explaining the nature of the Tunguska phenomenon. The most common of them is the fall of the meteorite (presumably iron) or passing meteor swarm - was quickly called into question because meteorite fragments have not been found.

Despite the doubts in meteorite nature of the explosion, the enthusiasts continued to search for a crater (or craters) in the area of the suggested epicenter, and not without success.

For example, in 1994 participants of the research association "Kosmopoisk" Romeiko managed to make a successful aerial Stony Tunguska region. The pictures clearly show the outlines of a mysterious lake, located a few dozens of kilometers from the epicenter of the alleged explosion.

The lake is of round shape, and its area is 200 to 250 meters. The shores of the reservoir are covered by forest, where some trees are felled. Since Taiga is difficult to pass in that area, the place had previously been virtually unknown. According to the hypothesis of Romeiko, it is a water-filled crater of meteoritic origin.

Researchers from Bologna led by a specialist in marine geology Luca Gasperini ran into another "crater" in 2007. The Italians drew attention to the taiga Lake Cheko that lies eight kilometers north-west of the alleged epicenter of the explosion. The location of the reservoir coincides with the flight path of a giant body that later without good grounds became known as the Tunguska meteorite. It is interesting that Lake Cheko is not observed on any map made before 1929, and according to the testimony of local residents, prior to the crash in 1908 it simply did not exist.

Under The project "Tunguska 99," Gasperini and his colleagues conducted a study of the lake on the ground. First of all, they were struck by its nearly hemispherical form. It was also found that the bottom of the reservoir has the shape of a cone, and its maximum depth is about 50 meters. This may indicate that something huge had struck the tunnel at this point and sank into the ground. Indeed, the ground penetrating radar recorded a large object at a depth of 10 meters below the bottom of the lake.

The Italian scientists suggest that the "culprit" was a fragment of an exploded cosmic body. The weight of the "fragment" is about 1,5 × 106 kilograms.

Yet, the discovered "craters" are still just a speculation. To date, no object was found in the Stony Tunguska that would clearly indicate that they are relevant to the old events.

Irina Shlionskaya

Fonte: Pravda.Ru

Meteorite lights up Ostrobothnia sky

An exceptional bright light phenomenon was observed in many parts of Ostobothnia, western Finland, just after 5pm on Tuesday. According to the Ursa astronomical association, this was a meteorite which had passed through the Earth’s upper atmosphere before hitting the ground.


According to Esko Lyytinen of Ursa, the object definitely made it to the ground. He speculated it could be as heavy as dozens of kilograms. The object’s final explosion occurred probably between the towns of Kalajoki and Ylivieska.  

Several observations of the object were made by Ursa at locations across Ostrobothnia. The subsonic blast was heard over a wide area.

Amateur astronomers are now eager to find the heavenly body which lies somewhere in the area of Ylivieska and Kalajoki.

Meteorites are a rare occurrence whereas meteors, objects that fail to reach the Earth’s surface, are more common. For example, during the course of the year, the Earth passes through dust clouds which give rise to a phenomenon known as a “meteor shower.”  During such an event, streaks of light caused by small rocky particles are visible at regular intervals in the night sky.


Fonte: yle.fi

Egypt’s extraterrestrial heritage

Some sites are beyond the traditional classification of heritage, yet are worthy of attention and protection, such as Egypt's Kamil Crater which was only even noticed using Google Earth



A few years ago, New Zealand called on the UNESCO to put one of its sites, Aoraki Mackenzie, on the World Heritage List. The site is a Dark Sky Park, known as one of the best spots on earth for stargazing. The call was rejected because there were no categories under which the site could be listed. Moreover, the ‘sky’ in itself does not belong to anyone and is not an ‘earthly’ heritage. In Egypt, it is not the sky that raises the debate; it is actually things falling from the sky!


Vagabonds from outer space

“Subject to the mercy of wind, a grain of sand is an eternal vagabond” – Cassandra Vivian, Islands of the Blest

And subject to the mercy of gravity, a meteoroid is a vagabond, too, until it hits another body in space. When this ‘body’ is our planet Earth, the consequences can be apocalyptic. One look at the moon is enough to understand why: Theories hold that it was formed following a catastrophic impact involving a body from space colliding with our planet. The debris eventually cooled off and, attracted by gravity, gave birth to the moon. But such impacts are not always that grand, and we do not have to go as far as the moon to imagine the possible outcome: Egypt has quite a track record of such collisions, and Nakhla village in Beheira is a good place to start.

In 1911, something happened in Nakhla that the little village would remember ever after. On the morning of June 28 of that year, the locals saw a meteorite shower over their village. They did not understand what it was, and obviously did not know the treasure that this shower had brought: this was one of the few meteorites in history to be identified as proceeding from Mars. Eventually, this meteorite would immortalize the name of the village, being the prototype of a famous type of meteorites: The Nakhlites.

Folk tales are not lacking on this incident. An urban legend holds, for example, that a dog was in the wrong time and place when the meteorite hit, and it simply vanished in the air due to the impact. Back to tangible evidence, and apart from specimen scattered in museums around the world, one can still contemplate meteorite fragments from Nakhla at the Egyptian Geological Museum in Cairo. There, visitors can see fragments from


another, much larger and older meteorite.

Gebel Kamil Crater

The silicon in the rocks, the oxygen in the air, the carbon in our DNA, the gold in our banks, the uranium in our arsenals were all made thousands of light years away and billions of years ago … we are made of star stuff.” – Carl Sagan, Cosmos

Star-stuff is what we can call the meteorite debris of Gebel Kamil. It took the Italian mineralogist Vincenzo de Michele a lot of time and hard work to spot a crater that bears witness to yet another meteorite collision. He found it in Egypt’s Western Desert, surprisingly, using Google Earth.

The Gebel Kamil Crater is a relatively recent one, a few thousand years old. Its importance lies in the fact that it is “one of the best preserved craters yet found on Earth” as National Geographic described it, since craters that size are usually eroded or have disappeared completely.

Over the last couple of years, meteorite fragments from the Kamil Crater appeared on the black market, both physically and online. Collectors from all over the world can buy these fragments and very little can be done to recover them. We have yet to figure out how protect this remote area, almost on the border with Sudan.


Egypt's extraterrestrial heritage

Heritage, by definition, is not necessarily man-made. In the case of Egypt, natural heritage is clearly visible in such sites as Gebel Elba, the White Desert, Ras Mohamed and elsewhere. Many of these sites are national parks, and one of them is even a UNESCO World Heritage Site (namely Wadi Al-Hitan).

This means that, at least in theory, these sites enjoy some measure of protection and have a management and conservation plan in place. This is also the case with sites like Gebel Kamil Crater, which, since March 2012, is a protected area. A problem arises, however, because many people fail to see why we should celebrate such a site as heritage in the first place.

What heritage values are there in an alien body hitting a spot in our desert and leaving a scar? How can we classify this heritage and what would be its type? Why and how should we protect it?


Apart from its value for geologist and mineralogists, the Kamil Crater (and other such sites) represent a very rare type of heritage…one that involved a unique astronomical phenomenon in Egypt thousands of years ago and that changed part of its topography for good. Meteorites are visitors from other worlds, and in the case of the Nakhla Meteorite, the fragments are believed to have been formed over one billion years ago. This makes them like time capsules; storing a priceless record of our cosmic history and helping us better understand the evolution of our solar system and the evolution of life itself.

The toughest question remains: how to protect this heritage, apart from technicalities such as declaring the site a protected area.

Spreading awareness and educating people about its existence and its significance is a first step. Only then will people behave as stakeholders and perceive the site as something worth protecting, investigating and passing on to future generations.



Fonte: http://english.ahram.org.eg

Meteorites, not comets, may have brought water to Earth

Modern Earth is wet and temperate (last week's heat wave aside), but the early Earth was molten and hostile, meaning water and other volatile substances like hydrogen and nitrogen compounds must have been deposited after formation. The likely culprits are comets—full of water ice and organic compounds—and meteorites, which were likely more water-laden in the early days of the Solar System. Knowing exactly where Earth's water and organic molecules originated would reveal a great deal about our planet's history and help us understand the environment in which life arose.

In a Science article, Conel Alexander and colleagues compared the abundance of deuterium—the isotope of hydrogen with a proton and neutron instead of just a proton—and nitrogen isotopes across several types of delivery candidates. They found significant differences between comets and meteorites, indicating they likely formed in different regions of the Solar System. They also argued that comets were unlikely to be the source of water and other volatiles now present in the inner Solar System.

In particular, primitive meteorites known as CI chrondrites bear the closest resemblance to the primordial components of the terrestrial planets, meaning they may be responsible for the wet Earth we inhabit today.

CI chrondrites are a subclass of common rocky meteorites known as the carbonaceous chondrites (CC); CI stands for "carbonaceous Ivuna," named for the region in Africa where they were first identified. As the name suggests, CCs contain carbon compounds, while "chrondrite" refers to the internal structure of the meteorites. CCs—including CIs—are probably fragments of asteroids from the Asteroid Belt region between Mars and Jupiter.

Water is abundant in the Solar System, but the frequency with which deuterium replaces one of the ordinary hydrogen atoms in the H2O varies with location. Objects that formed close in to the Sun have less deuterium than those that formed farther out. Therefore, measuring the relative abundance of deuterium to regular hydrogen in an object provides some information about where it formed within the solar nebula—the cloud of gas and dust from which planets, meteorites, and comets formed. Deuterium isn't that common anywhere, so the abundance is generally reported in parts per thousand (‰) rather than the more familiar percentages, or parts per hundred (%).

The authors of the study examined 86 chondrite meteorite samples and compared them to a number of other Solar System objects, including comets and Saturn's moon Enceladus (using data obtained from the Cassini spacecraft). Since meteorites don't have a lot of water content, they couldn't do a direct comparison using water alone. Instead, they examined the deuterium fraction in general, and used other volatiles—carbon compounds and an isotope of nitrogen—as proxies for water content. They found a clear division between the comets and many of the CCs: comets were relatively high in deuterium, while most chondrites contained less than that found in seawater on Earth.

Enceladus turned out to be remarkably comet-like, while the Jupiter family comets (or JFCs, comets originating in the region between Jupiter and Saturn) resembled Earth in deuterium abundance. The researchers suggested this may be due to a complex relationship between deuterium content and distance from the Sun, since JFCs are not likely to be the source of Earth's water.

However, the CI chondrites had the most obvious correspondence to the chemistry of the Earth-Sun system in the early days of the Solar System. Based on their dissimilarity to comets, the authors argue they could not have formed in the outer Solar System, which has been suggested in other models. This has two immediate consequences: comets were unlikely to be the source of Earth's volatiles based on the isotope analysis, and Earth's water probably came from the Asteroid Belt, carried by CC meteorites.


Fonte: arstechnica.com

13-year-old boy using metal detector finds 2-pound meteorite

Jansen Lyons, 13, searches for a meteorite near his home in Rio Rancho, N.M. After years of searching and several thousand misses, he finally found his first. 

As the director of the University of New Mexico's Institute of Meteoritics, Carl Agee gets tons of calls, packages and emails from people claiming to have had the rare experience of actually finding a meteorite.

Sadly for Agee, most are merely terrestrial rocks, what he calls meteor-wrongs.

Then he met 13-year-old Jansen Lyons. Two weeks ago, the teenager walked into the institute – his mother in tow – carrying what he said was a 2-pound hunk of space rock he found at an undisclosed location in the Albuquerque suburb of Rio Rancho.

Skeptical, Agee took a look-see. And sure enough, he confirmed this week, the lad had located a large "L6 ordinary chondrite" that Agee estimates had been on the ground for about 10,000 years.

Agee told the Los Angeles Times that after yelling and hurrahing, he told Lyons he had a sure-fire career as a scientist.

“Meteorites are rare – it’s difficult to find them. And usually where they’re located are in well-known localities, places where there are existing craters or strewn fields, so people know where to hunt for them,” Agee told The Times.

“But to find a meteorite on a hike using a homemade metal detector – not to mention being only 13 – is frankly quite extraordinary. But this kid is really bright. He’s home-schooled and he’s going to make a great scientist someday.”

Jansen found the meteorite last September. He told the Associated Press that he developed an interest in meteorites in 2008 after reading a book that belonged to his brother. Since then, his fascination skyrocketed so much his grandfather eventually designed and built him a metal detector to assist in his searches. Jansen now has three metal detectors.

"I've turned over every single rock in our backyard several times," he told the AP.

But when he found the meteorite last year at a location the family does not want to disclose, he said, he knew he had something special. The rock has a unique fusion crust and a tell-tale black coating.

Meteorites are remnants of asteroids, or sometimes comets, that fall from the sky onto Earth's surface. The one Jansen found is the second-most common type and is composed in part of nickel-iron metal.

He called the university meteorite institute, which had been closed for months, even though many people doubted the veracity of his find. “I promised my mom that if anyone tried to say it's not a meteorite, I was going to prove them wrong," he said.

Jansen is keeping the meteorite, although a small chunk will be displayed at the museum. "I think it'd be a really great shame to sell it," he said.

Agee is still amazed this meteorite just dropped on his doorstep.

“It’s a nice-sized sample,” he said. “It’s not a boulder, but it’s not a bb-sized pebble either. It’s something you can hold in your hand.”

He said the rock will be named the Rio Rancho Meteorite.

Meteors are never named after their finders, he said. “Asteroids maybe, but meteorites are always named after their localities.”

He said he wasn’t sure whether Jansen was disappointed. “No matter what it’s called,” Agee said, “it’s quite a find.”


Fonte: latimes.com

Canadian astronaut prepares for mission to study the MOON in the High Arctic

It turns out the remote Arctic is a good place to learn about the moon.

Canadian Space Agency astronaut Jeremy Hansen is preparing for international missions to the moon or Mars by studying a suspected meteorite impact site 26 kilometres wide near Collinson Inlet on the Northwest Territories side of Victoria Island, a two-hour flight from Cambridge Bay.

The 10-day trip started July 1, lead by Gordon Osinski of the University of Western Ontario, acting director of the UWO’s Centre for Planetary Science and Exploration, and a team of four researchers.

The research is aimed at helping inform astronauts about what they may find during future space exploration.

“We’re going to want to know what the structures are and what the resources may be,” Hansen said in an interview from Collinson Inlet.

Either way, the geology training will benefit Hansen, because it mimics what he might experience on a trip to the moon or to Mars.

“I think we’ll likely end up going back to the moon, while we make preparations to go to Mars,” Hansen said.

Team members also have to rely on each other and deal with Mother Nature, Hansen said, while approaching the work as geologists.

The Canadian Arctic could play a significant role in future space missions, he said.

“We largely take the Arctic for granted, but it really is an important part of Canada,” he said, adding Nunavut youth need to start looking at careers in the field — because voyages to Mars may be happening in their lifetimes.

The site on Collinson Inlet is home to a large canyon, and the team has two ATVs to use during their stay — so they will visit only a small portion of the crater.

“It’s a lot of ground to cover,” Hansen said.

The next step is to determine the size and age of the meteorite crater, which is the most common type of geological feature on the moon.

Hansen’s hands-on training is similar to what U.S. astronauts Charles Duke and John Young received in Sudbury, Ont., preparing in 1971 for the Apollo 16 mission, when they spent 71 hours on the surface of the moon.

Meteorite impacts, if big enough, can create enough heat and rock movement to create rich deposits of iron, uranium, diamonds and other valuable materials.

The Sudbury mining district was formed nearly two billion years ago when an asteroid hit a 10-kilometre area, generating ore in the process that is now worth more than $10 billion.

Evidence of a great collision can come in the form of shatter cones—the only characteristic evidence of shock, or, proof of an impact event.

“Found our first shatter cone! Strong supporting evidence that we are in a meteorite impact crater. Some happy Geologists!” Hansen said on Twitter.

The entire team was excited about it. “Amongst a lot of great folds and fascinating strata, we found the absolute motherload of shatter cones!”

This means the the trip has been a success.

The team spent the first night unloading gear and watching their pilots head for Resolute, their first point of contact in an emergency, leaving the crew with “equipment, each other, and nothing else but empty, silent tundra for hundreds of kilometers in every direction,” they wrote on http://cpsx.uwo.ca/research/field-sites/victoria-island?pp=1&category_id=152#news” target=“_blank” title=“their blog.”>their blog.

The camp is set up with a dome tent for kitchen and science work and personal sleeping tents, an outhouse tent, two ATVs, a gasoline generator, two solar PV-arrays or panels, a satellite phone and modem, and a rifle to ward off bears.

The researchers are using standard geology tools such as hammers and compasses, but also light detection and ranging technology and a 3D stereo camera imaging system.

“This analogue mission is very much what a real mission will be like. None of the team has ever been to this site and very little is known about this region of the Arctic,”  head geologist Osinski said in a news release.

To date, Osinski has gone on 13 Arctic field expeditions.

Hansen is a former Canadian Armed Forces fighter pilot and graduated from NASA astronaut candidate training in 2011.

He’s been assigned as crew support astronaut for the 34th expedition to the International Space Station, set to launch in November 2012.



Fonte: nunatsiaqonline.ca

Fire in the sky: Burning meteorite trail lights up Australian sky for 20 minutes after rock plunges into the sea

A burning trail lit up the sky over Australia for 20 minutes after an object suspected to be a meteorite plunged into the sea, leaving a burning orange trail that mesmerised local residents

A burning trail lit up the sky over Western Australia for 20 minutes after an object suspected to be a meteorite plunged into the sea, leaving a burning orange trail that mesmerised local residents.
Beachgoers in Perth debated what could have caused the strange burning line in the sky, which persisted for 20 minutes. Most meteorite trails are only seen briefly - and seeing an object plunge into the sea is rare.

Local resident Gavin Trought captured a picture of the 'burning streak', saying, 'The weird streak in the sky seen from Cottesloe last night. I noticed it just before sunset.'
Meteorites are fragments of rock that land on Earth's surface. Those that burn up - 'ablate' - in Earth's atmosphere are referred to as meteors.
The meteorite was reported by Perth Now.
Seeing such clear, fiery trails is rare.
Perth journalist Pip Moir posted a photo she took at Cottesloe Beach to Twitter shortly after 6pm as puzzled onlookers debated what caused the colourful phenomena.
Daniel Jongue, manager at Perth's The Naked Fig Cafe, said he saw ‘something on the horizon'' just before sunset.
Jonque said that the fiery trail lasted for around 20 minutes.

‘It looked like vapour. It was red, orange and yellow and quite beautiful,' he said.
Meteorites are fragments of rock and sometimes metal that survive the fall to Earth from space. Most are fragments left over from the collision of two asteroids.
Captured by Earth's gravitational force, they are accelerated to speeds of over 11.2 kilometres per second.
They can vary in size from a fraction of a millimetre to larger than a football pitch. It is believed a meteorite six miles across wiped out the dinosaurs 65million years ago.
Hundreds of meteorites fall to Earth each year but only a handful are recovered.


Fonte: dailymail.co.uk