That meteorite which blew-up over California last April is one of the rarest ever found

This past April, a 100,000 pound (45,360 kg) meteorite exploded above the skies of Sutter's Mill, California. Streaking in at a speed of 64,000 miles per hour (103,000 km/hr or 28.6 km/s) — about twice the speed of typical meteorite falls — it hit with the energy of a quarter of a Hiroshima bomb, making it the biggest impact over land since a four meter-sized asteroid broke-up over Sudan four years ago. And now, after recovering and analyzing the ensuing meteorite fragments, scientists have realized that it's an incredibly ancient form of rock — one that may have brought compounds crucial for life to Earth.
After disintegrating over California in a 4-kiloton explosion, a team of scientists (including NASA researchers from Ames) scrambled to recover the fragments.


They managed to find a paltry 205 grams worth in the form of 77 pieces, but it was enough to conduct an analysis. They located the exact region where the fragments fell by using doppler weather radar — the first time this technique was used for such a purpose.

Based on photographs of the fireball, the object entered into Earth's atmosphere at an unusually low-inclined comet-like orbit that at one point reached the orbit of Mercury. Consequently, it passed closer to the sun than other recovered meteorites. But at the same time, it experienced an unusually short exposure to cosmic rays. The scientists suspect that it circled the sun three times during a single orbit of Jupiter, an important piece of insight into the object's point of origin.


The ensuing study, which was conducted by Peter Brown and colleagues at Western University and Peter Jenniskens of the SETI Institute, reveals that it was a rare carbonaceous chondrite meteorite — a so-called C-class asteroid that likely came from the Eulalia asteroid family. This is a very primitive class of asteroids that are very rarely discovered. Specifically, it's a regolith breccia that originated from near the surface of an ancient asteroid, possibly in the vicinity of Jupiter.

And importantly, the debris contained carbon. It's rocks like these, say the scientists, that contributed to the early organic chemistry on Earth — the same carbon atoms that can be found in biological matter.

Interestingly, NASA plans on sending astronauts to asteroids like these on future missions.

You can read the entire paper at Science.


Source: http://io9.com

Antarctic meteorite hunters

For more than 35 years, scientists from the Antarctic Search for Meteorites (ANSMET) program have been scouring glacial landscapes in search of meteorites. Since 1976, teams of physicists, meteorite specialists, and mountaineers have recovered thousands of untouched specimens from meteoroids, the moon and even Mars. Despite subzero temperatures and razor-sharp winds, scientists are lining up for the chance to experience the ultimate hunt for alien objects in the alien environment.

ANSMET teams either conduct systematic searches of a region or work as a scout teams making preliminary investigations of new sites that might be worth further exploration. Once discovered, the meteorites are carefully cataloged in the field and sent to the Smithsonian's National Museum of Natural History in Washington, D.C., where they are distributed to scientists for further research. What secrets will new specimens – locked away in the ice and yet to be discovered – hold about our solar system and the universe? Read the story online and find out at http://bit.ly/UtXc9R.

Read this story and more in the December issue of EARTH Magazine, available online now. Learn how mummification emerged from environmental change; discover the explosive combination of red giants and white dwarfs; and see what states are paying to dispose of low-level radioactive waste all in this month's issue of EARTH.

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Keep up to date with the latest happenings in Earth, energy and environment news with EARTH magazine online at http://www.earthmagazine.org/. Published by the American Geosciences Institute, EARTH is your source for the science behind the headlines.

The American Geosciences Institute is a nonprofit federation of geoscientific and professional associations that represents more than 250,000 geologists, geophysicists and other earth scientists. Founded in 1948, AGI provides information services to geoscientists, serves as a voice of shared interests in the profession, plays a major role in strengthening geoscience education, and strives to increase public awareness of the vital role the geosciences play in society's use of resources, resiliency to natural hazards, and interaction with the environment.



Source: EARTH http://www.eurekalert.org

Meteorite ‘Tautetis’ to come closer to Earth today

Wednesday afternoon will be very special for astronomers when a large meteorite is predicted to pass closer to the earth. According to N Raghunandan Kumar, Director and secretary of Planetary Society of India, the asteroid, 4179 Tautetis, will pass very close from Earth at a distance of 69 lakh 31 thousand 175 kilometers from the blue planet.

Though, there is nothing to be scared of it. The meteorite will come closer to Earth on Wednesday afternoon. This meteorite is moving at a speed of 11.9 km per second. The meteorite comes from a region nearby Earth and it has its own orbit too. Given its large mass, it predicted that it could destroy some parts of the Earth.

The meteorite was discovered on January 4, 1989 and was named after tribal icon Tautetis. It is expected that it will come close to Earth again on December 16, 2016. Earlier it was viewed closer to the Earth on November 9, 2008. After December 16, 2016, it would not appear until 2069 in the vicinity of the Earth.



Source: http://post.jagran.com

Mysterious space object in Central Highlands skies solved

The suspicious cloud of smoke which appeared in the sky on Monday is said to have been a meteorite. Plenty of Australian locals witnessed the event.

A LOUD boom followed by a cloud of smoke in the sky had many Central Highlands Australia residents taking a closer look on Monday.

Many residents speculated the theory behind the mysterious object was a meteorite heading for Earth at the speed of sound and disintegrating on entry.

A spokesman from the Bureau of Meteorology said that theory was most likely the correct explanation.

"We had a call from an Emerald resident at about 7pm (Monday night), wanting to know what it was," the spokesman said.

"It could have been a meteorite... or it may have been a bit of space debris."

If it was a meteorite, it could have been about 20,000 feet high, and the sound residents heard would have been a shockwave.

"If they come low enough they can cause a sonic boom as they enter the atmosphere lower down," the spokesman said.

"Not very loud, but distinctive … if they come into the troposphere - which is the lower atmosphere - when they lose velocity, you might hear a series of booms."

He said once it hit Earth, it would have been about the size of a small pebble and where it hit would be hard to determine.

"Depending on the direction it was coming through, it could have landed 100km (from where it was seen)," the spokesman said.


Source: http://www.cqnews.com.au

Beyond 2012: Why the World Won't End in 2012. NASA scientists answer questions on the following 2012 topics:

Beyond 2012: Why the World Won't End in 2012. NASA scientists  answer questions on the following 2012 topics:



Question (Q): Are there any threats to the Earth in 2012? Many Internet websites say the world will end in December 2012.
 Answer (A):The world will not end in 2012. Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012.


Q: What is the origin of the prediction that the world will end in 2012?
 A: The story started with claims that Nibiru, a supposed planet discovered by the Sumerians, is headed toward Earth. This catastrophe was initially predicted for May 2003, but when nothing happened the doomsday date was moved forward to December 2012 and linked to the end of one of the cycles in the ancient Mayan calendar at the winter solstice in 2012 -- hence the predicted doomsday date of December 21, 2012.


Q: Does the Mayan calendar end in December 2012?
 A: Just as the calendar you have on your kitchen wall does not cease to exist after December 31, the Mayan calendar does not cease to exist on December 21, 2012. This date is the end of the Mayan long-count period but then -- just as your calendar begins again on January 1 -- another long-count period begins for the Mayan calendar.


Q: Could planets align in a way that impacts Earth?
 A: There are no planetary alignments in the next few decades and even if these alignments were to occur, their effects on the Earth would be negligible. One major alignment occurred in 1962, for example, and two others happened during 1982 and 2000. Each December the Earth and sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence.
› More about alignment

"There apparently is a great deal of interest in celestial bodies, and their locations and trajectories at the end of the calendar year 2012. Now, I for one love a good book or movie as much as the next guy. But the stuff flying around through cyberspace, TV and the movies is not based on science. There is even a fake NASA news release out there..."

- Don Yeomans, NASA senior research scientist
Q: Is there a planet or brown dwarf called Nibiru or Planet X or Eris that is approaching the Earth and threatening our planet with widespread destruction?

 A: Nibiru and other stories about wayward planets are an Internet hoax. There is no factual basis for these claims. If Nibiru or Planet X were real and headed for an encounter with the Earth in 2012, astronomers would have been tracking it for at least the past decade, and it would be visible by now to the naked eye. Obviously, it does not exist. Eris is real, but it is a dwarf planet similar to Pluto that will remain in the outer solar system; the closest it can come to Earth is about 4 billion miles.


Q: What is the polar shift theory? Is it true that the Earth's crust does a 180-degree rotation around the core in a matter of days if not hours?
 A: A reversal in the rotation of Earth is impossible. There are slow movements of the continents (for example Antarctica was near the equator hundreds of millions of years ago), but that is irrelevant to claims of reversal of the rotational poles. However, many of the disaster websites pull a bait-and-switch to fool people. They claim a relationship between the rotation and the magnetic polarity of Earth, which does change irregularly, with a magnetic reversal taking place every 400,000 years on average. As far as we know, such a magnetic reversal doesn’t cause any harm to life on Earth. Scientists believe a magnetic reversal is very unlikely to happen in the next few millennia.
› More about polar shift


Q: Is the Earth in danger of being hit by a meteor in 2012?
 A: The Earth has always been subject to impacts by comets and asteroids, although big hits are very rare. The last big impact was 65 million years ago, and that led to the extinction of the dinosaurs. Today NASA astronomers are carrying out a survey called the Spaceguard Survey to find any large near-Earth asteroids long before they hit. We have already determined that there are no threatening asteroids as large as the one that killed the dinosaurs. All this work is done openly with the discoveries posted every day on the NASA Near-Earth Object Program Office website, so you can see for yourself that nothing is predicted to hit in 2012.


Q: How do NASA scientists feel about claims of the world ending in 2012?
 A: For any claims of disaster or dramatic changes in 2012, where is the science? Where is the evidence? There is none, and for all the fictional assertions, whether they are made in books, movies, documentaries or over the Internet, we cannot change that simple fact. There is no credible evidence for any of the assertions made in support of unusual events taking place in December 2012.
› Why you need not fear a supernova
› About super volcanoes


Q: Is there a danger from giant solar storms predicted for 2012?
 A: Solar activity has a regular cycle, with peaks approximately every 11 years. Near these activity peaks, solar flares can cause some interruption of satellite communications, although engineers are learning how to build electronics that are protected against most solar storms. But there is no special risk associated with 2012. The next solar maximum will occur in the 2012-2014 time frame and is predicted to be an average solar cycle, no different than previous cycles throughout history.
› Video: Solar Storms
› More about solar storms


Addition information concerning 2012 is available on the Web, at:
National Public Radio: "Ask A NASA Astrobiologist About Dec. 21 'Doomsday'"
NASA Astrobiology Institute: "Nibiru and Doomsday 2012"
Bad Astronomy: "The Planet X Saga: The Scientific Arguments in a Nutshell"
Sky and Telescope Magazine: "2012: The Great Scare"
Phys.org: "Mayan People Demand End to Doomsday Myth"
Houston Museum of Natural Science: "Maya 2012: Prophecy Becomes History"

You may participate in this FORUM (click here to join):  https://plus.google.com/events/ci7ak9p657rj34um819vadrm8jg


Source: http://www.nasa.gov

Former Sackville School scientist chosen for Christmas trip to Antarctica

A METEOROLOGIST has been guaranteed a white Christmas after she was accepted to participate in a science expedition in Antarctica.

Former Sackville School student Dr Katherine Joy will fly to the southern-most continent on Earth for the second successive year where she will hunt for meteorites that have crashed onto its frozen surface.


The mission, which has run since 1976, is funded by the US National Science Foundation and the Solar System Exploration division of NASA, and its findings will be submitted to the space agency to be studied.

Dr Joy said: "There are meteorites all over the world but as there is no rain in Antarctica they cannot be washed away, nor can their structures change. They are also a lot easier to find because they are black in the white snow.

"The most exciting discoveries are the meteorites from the Moon and Mars; they are the rarest that we find. Using snow mobiles, we go to different sites, or we go on foot to search through rocks.

"Depending on the weather we should spend eight hours a day out hunting for the meteorites and because we will be there during Antarctica's summer it will be light all the time.

"Our findings, which can vary from day to day, will then be stored and taken to NASA in Houston and the Smithsonian Institution in Washington to be analysed. We'll be studying to find out the usual things like the age, origin and how planets may have been formed. Meteorites can also give us an insight into planetary volcanoes."

Dr Joy will spend a total of two months in Antarctica with a team of between eight and twelve international planetary scientists and will also celebrate the New Year on the continent.

In December she flies to Christchurch, New Zealand, where the team will pick up some special clothing to combat the cold before flying in a ski-equipped plane to McMurdo Station, the largest base on Antarctica.

The meteorologist will return to Manchester University, where she works as a researcher, at the end of January while other scientists compile the expedition's findings.

She said: "I will spend a total of six weeks out camping with the team, which is more luxurious than it sounds, certainly more so than Scott and Shackleton experienced.

"We have power and food supplies.

"One of the positives is that I get to eat a lot of chocolate as we burn so many calories throughout the day.

"The team will spend Christmas Day exchanging presents with each other and last time I was on the trip I spent New Year's Eve watching a midnight sun, which was one the best memories I have."

To follow the expedition visit the team's blog


Source: http://www.thisissussex.co.uk

Study Suggests Earth, Mars Share Primordial Water Source, Chondritic Meteorites

In their earliest eras, the Earth, Mars and the solar system's other rocky planets drew water from the same source, chondritic meteorites -- not usually credited comets, suggest recent studies of two primitive space rocks of Martian origin.


The findings also suggest the Earth and Mars evolved quite differently, supporting wider evidence of a significant surface water presence in the distant Martian past that disappeared over time along with a more substantial atmosphere.

NASA's closely watched Curiosity rover has been at work on similar "habitability" questions on the red planet since its much heralded landing at the base of Mount Sharp in Gale Crater
nearly four months ago (Aug. 6).

On Earth, researchers from the Tokyo Institute of Technology, NASA's Johnson Space Center, the Lunar and Planetary Institute and the Carnegie Institution for Science drew their conclusions from the 79 gram Larkman Nunatak 06319 meteorite, which was recovered from Antartica in 2006, and the 82 gram Yamato 980459 Martian rock found in Antarctica in 1998, two of 62 rocks listed in NASA's Martian Meteorite Compendium.

Their findings are set for publication in the Earth and Planetary Science Letters of Dec.1, as "Origin of water and mantlecrust interactions on Mars inferred from hydrogen isotopes and
volatile element abundances of olivine-hosted melt inclusions of primitive shergottites."

The two volcanic rocks differ in the richness of their elemental composition, affording telltale comparisons between their ratios of elemental hydrogen and deuterium, the isotope of hydrogen with a neutron added to the nucleus.

"These meteorites contain trapped basaltic liquids, not unlike the basalts that erupt on Hawaii," John Jones, an experimental petrologist from NASA/Johnson, a study co-author and a member of the Curiosity science team, explained in a statement. "They are pristine samples that have sampled various Martian volatile element environments."

Yamato 980459's H/D ratio was Earth-like, suggesting a similar primordial origin for Martian water.


But the amount of water trapped in Yamato's crystalline structures was quite dry, 15 to 47 parts per million. Yamato, the "depleted" meteorite, made its way from the Martian mantle to the crust little altered before it was blasted away on a trajectory that would bring it to Earth, the five member research team led by Tomohiro Usui, of the Tokyo Institute of Technology and a former NASA/ LPI postdoctoral fellow, surmises.

Lar 03619, the "enriched" meteorite, exhibited 10 times as much trapped water and an H/D ratio that suggested interactions with a surface reservoir in the Martian crust as well as the atmosphere, according to researchers.

The sculpted channel features in the ancient terrain of the Martian southern hemisphere suggest as much, they note in a collection of pre-publication announcements from the four study institutions.



Source: www.aviationweek.com