Science & TechnologyS


Telescope

Quiet Explosion: Object Intermediate Between Normal Supernovae And Gamma-ray Bursts Found


Science Daily
Fri, 25 Jul 2008 12:16 UTC
A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts.

Image
©ESO
The spiral galaxy NGC 2770 and its two supernovae as observed at the Asiago Observatory. The image was obtained on 12 January 2008 and shows the then fading SN 2007uy and the newly discovered SN 2008D.

The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe.

These striking results, partly based on observations with ESO's Very Large Telescope, will appear tomorrow in Science Express, the online version of Science.

Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays.
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Info

Scientists Solve 30-year-old Aurora Borealis Mystery


Science Daily
Fri, 25 Jul 2008 12:08 UTC
What causes the shimmering, ethereal Northern Lights to suddenly brighten and dance in a spectacular burst of colorful light and rapid movement?

Image
©NASA
Artist's concept of a substorm.

UCLA space scientists and colleagues have identified the mechanism that triggers substorms in space; wreaks havoc on satellites, power grids and communications systems; and leads to the explosive release of energy that causes the spectacular brightening of the aurora borealis, also known as the northern lights.

For 30 years, there have been two competing theories to explain the onset of these substorms, which are energy releases in the Earth's magnetosphere, said Vassilis Angelopoulos, a UCLA professor of Earth and space sciences and principal investigator of the NASA-funded mission known as THEMIS (Time History of Events and Macroscale Interactions during Substorms).

One theory is that the trigger happens relatively close to Earth, about one-sixth of the distance to the moon. According to this theory, large currents building up in the space environment, which is composed of charged ions and electrons, or "plasma," are suddenly released by an explosive instability. The plasma implodes toward Earth as the space currents are disrupted, which is the start of the substorm.
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Target

Siberia forest blast captivates Wollongong scientist

Brett Cox
Illawarra Mercury News
Fri, 25 Jul 2008 10:39 UTC
It's a question that has had scientists arguing for 100 years.

Now, after many came together for conferences a century after the "Tunguska Event" in a Siberian Forest, the arguments continue.

On June 30, 1908, a blast, hundreds of times more powerful than the Hiroshima atomic bomb, destroyed about 2000sq km of forest but left no obvious crater.

Image
©Illawarra Mercury News
Wollongong academic Ted Bryant at the Tunguska site.
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Evil Rays

Hang up and drive. Dissociation the biggest risk with cellphones and driving

Katharine Mieszkowski
Salon
Fri, 25 Jul 2008 10:13 UTC
For years, psychologists who study driving and attention have argued that switching to "hands free" is not a real solution to the hazards caused by yakking on the mobile in the car. "The impairments aren't because your hands aren't on the wheel. It's because your mind isn't the road," says David Strayer, professor of psychology at the University of Utah, whose research has found driving while talking on a cellphone to be as dangerous as driving drunk.
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Fish

Exploration of underwater forest


BBC News
Tue, 15 Jul 2008 14:20 UTC
Underwater archaeologists are taking to Loch Tay to try to uncover more about a submerged prehistoric woodland.

Tree Stump 4270 BC
©Unknown
One of the tree stumps could date back to 4,270 BC
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Frog

Human-Frog hybrids used to study autism


Asian News International
Fri, 25 Jul 2008 08:28 UTC
Scientists at the University of California at Irvine are studying the way the brain cells of among autistic people behave by fusing cells from the preserved brains of deceased patients with the eggs of a carnivorous African frog called Xenopus.

The researchers say that frog eggs work a little like human neurons, and that the hybrid cells act as a surrogate of a living brain with the condition.
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Sherlock

'Yeti hair' to get DNA analysis

Alastair Lawson
BBC News
Fri, 25 Jul 2008 07:48 UTC


Yeti Hair
© Unknown
The microscope revealed 'the yeti' suffered from split ends

Scientists in the UK who have examined hairs claimed to belong to a yeti in India say that an initial series of tests have proved inconclusive.

Ape expert Ian Redmond says the hairs bear a "startling resemblance" to similar hairs collected by Everest conqueror Sir Edmund Hillary. He told the BBC the Indian hairs are "potentially very exciting". After extensive microscope examinations, the hairs will now be sent to separate labs for DNA analysis.
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Telescope

Asteroid Crash May Have Demagnified Mars

Irene Klotz
Discovery News
Thu, 24 Jul 2008 18:10 UTC
Scientists don't know what happened on Mars that caused its magnetic field to collapse. They suspect the planet's liquid metallic core cooled, ending convective currents that spread magnetic field lines through the planet's rock and soil and out into space.

Mars
©Unknown
Missing Magnetic Field

But that may just be part of the story.

A team of researchers led by Jafar Arkani-Hamed of the University of Toronto in Canada believe a large asteroid circling the planet set up a gravitational tug-of-war that got Mars' core churning. Eventually, the asteroid lost its grip and crashed into its parent planet. Mars paid a dear price as well. Without the tidal forces, the planet's core lost its momentum, killing off the magnetic field.

What remain are patches of strong magnetic imprints in the oldest parts of Mars' crust. Because the fresher surface features are magnetic-free, scientists believe Mars lost its shield about four billion years ago.

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Meteor

10 Greatest Major-Impact Craters on Earth (photo)


Environmental Graffiti
Fri, 18 Jul 2008 17:03 UTC


meteorite
©Unknown

Imagine staring into the sky and seeing a tiny yellow dot, gradually getting closer. That dot doubles in size every second, until it slowly darkens the sky. You realize that this dot is actually the size of New York City and is screeching through the atmosphere faster than the speed of sound, coming right for you. This massive object will cause tsunamis, earthquakes and obliterate natural daylight for years...oh... and it will kill you. Similar asteroid impacts have and will happen on numerous occasions in our earth's history. Today we'll show you the biggest impact craters by diameter.
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Cow Skull

Scientists find complete baby dinosaur fossil

Mari Yamaguchi
Associated Press
Thu, 24 Jul 2008 16:56 UTC
Japanese and Mongolian scientists have successfully recovered the complete skeleton of a 70-million-year-old young dinosaur, a nature museum announced Thursday.

The scientists uncovered a Tarbosaurus - related to the giant carnivorous Tyrannosaurus - from a chunk of sandstone they dug up in August, 2006 in the Gobi Desert in Mongolia, said Takuji Yokoyama, a spokesman for the Hayashibara Museum of Natural Sciences, a co-organizer of the joint research project.

"We were so lucky to have found remains that turned out to be a complete set of all the important parts," he said.
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