California Meteor Broke Speed Record For Atmospheric Entry

Posted: December 21, 2012

A meteor that flew through the California sky in April broke the speed record for atmospheric entry as it streaked through the sky as a massive fireball.
The incident took place on April 22 over northern California’s gold country, reports the Scientific American. Meteor astronomer Peter Jenniskens took the opportunity to search for pieces of the meteorite to study.
The meteorite was picked up by Doppler radar stations, allowing researchers to pinpoint the spot where it landed. Jenniskens and other researchers were able to pick up 77 pieces of the meteorite, though they were only a fraction of the object’s original mass.
The Scientific American notes that the meteor astronomer and his colleagues believe that the meteor hit the atmosphere at about 28.6 kilometers per second — or about 64,000 miles per hour. At that speed, the meteor broke the record as the highest entry velocity ever recorded for a recovered meteorite.
Named the Sutter’s Hill meteorite for it’s recovery area, the researchers were able to discover that the massive meteor was a rare variety called a carbonaceous chondrite. The Latino Post notes that the fragments recovered by Jenniskens and his colleagues may hold clues to the early stages of the universe.
The space rock is believed to have formed about 4.5 billion years ago and was part of a Jupiter-family comet that broke off around 50,000 years ago, according to The Latino Post. The meteor’s landing in April released the energy equivalent of about four kilotons of TNT, or about one-fourth the impact of the atomic bomb released on Hiroshima. Ed Allen, a resident in the area who heard the meteor land, recalled:

“I was out on my hillside burning some branches and so forth, and I heard this sonic boom. It wasn’t just one boom. It was a series of booms, literally right over my head.”

The meteor that broke the speed record displays “considerable diversity” of mineraology, petrography, and isotope and organic chemistry, according to Jenniskens. The meteor astronomer’s study about the California meteor will appear in the journal Science on Friday.

Scientists decode why universe is dominated by matter

PTI : Washington, Thu Dec 27 2012, 13:28 hrs

Scientists have solved the puzzle of the universe being dominated by matter rather than its close relative anti-matter.
Physicists at the University of Wisconsin-Madison made a precise measurement of elusive, nearly massless particles, and obtained a crucial hint as to why the universe is dominated by matter.
The particles, called anti-neutrinos, were detected at the underground Daya Bay experiment, located near a nuclear reactor in China.
Anti-particles are almost identical twins of sub-atomic particles (electrons, protons and neutrons) that make up our world. When an electron encounters an anti-electron, for example, both are annihilated in a burst of energy.
Failure to see these bursts in the universe tells physicists that anti-matter is vanishingly rare, and that matter rules the roost in today's universe.
"At the beginning of time, in the Big Bang, a soup of particles and anti-particles was created, but somehow an imbalance came about," says Karsten Heeger, a professor of physics at UW-Madison.
"All the studies that have been done have not found enough difference between particles and anti-particles to explain the dominance of matter over anti-matter.
"But the neutrino, an extremely abundant but almost massless particle, may have the right properties, and may even be its own anti-particle, Heeger said in a statement.
"And that's why physicists have put their last hope on the neutrino to explain the absence of anti-matter in the universe," he said.
Reactors, Heeger says, are a fertile source of anti-neutrinos, and measuring how they change during their short flights from the reactor to the detector, gives a basis for calculating a quantity called the "mixing angle", the probability of transformation from one flavour into another.
The measurement of the Daya Bay experiment even before the last set of detectors was installed, showed a surprisingly large angle, Heeger said.
"People thought the angle might be really tiny, so we built an experiment that was 10 times as sensitive as we ended up needing.

Shivalik Express: World’s second solar train

By Gaurav Bhatia, TNN | Dec 27, 2012, 05.53 AM IST

inShare10

Comments

READ MORE solar train|Shivalik Express

CHANDIGARH: The world's second solar train, Shivalik Express was officially launched on Friday. Just like the Himalayan Queen, this train is also equipped with solar panels.

Shivalik Express had been running between Kalka and Shimla for the past some years. The Northern Railways thought of converting it into a solar-powered train recently.

A lot of effort has gone into its making. R K Gupta, senior divisional electrical engineer at Ambala division of Northern Railways who claims it to his brainchild, said that he has been working on it for the past two months.

All lights in the new train have been replaced by LEDs and the illumination level has also been increased from 20 to 42 lux in all the seven coaches of the train.

Solar-powered sockets have been installed so that passengers can recharge their mobiles and cameras with ease, said Gupta, a passout of IIT Delhi.

Gupta, who recently got the president's medal for energy conservation, said converting the train into solar power required Rs 2.25 lakh but the benefit far outweighs the cost incurred.

He said that by turning the train solar, he has been able to reduce 435kg of weight from each of the seven coaches. By reducing the weight, the train will save diesel worth around Rs 1.50 lakh per annum, he pointed out.

The total savings would come to Rs 12.35 lakh per year as it includes the savings of wear and tear, maintenance, spare parts and manpower, Gupta averred.

The train departs daily from Kalka station in the morning at 5.30.