A mystery lurking at the center of our own Milky Way galaxy--an object radiating high-energy gamma rays--has been detected by an international team of astronomers, said spaceflightnow.com.
Their research was carried out using the High Energy Stereoscopic System (H.E.S.S.), an array of four telescopes, in Namibia, South-West Africa, Science Daily Online reported.
The Galactic Center harbors a number of potential gamma-ray sources, including a super massive black hole, remnants of supernova explosions and possibly an accumulation of exotic 'dark matter' particles, each of which should emit the radiation slightly differently.
The radiation observed by the H.E.S.S. team comes from a region very near Sagittarius A*, the black hole at the center of the galaxy.
According to most theories of dark matter, it is too energetic to have been created by the annihilation of dark matter particles.
The observed energy spectrum best fits theories of the source being a giant supernova explosion, which should produce a constant stream of radiation.
However, the team's theory doesn't fit with earlier results obtained by the Japanese /Australian CANGAROO instrument or the US Whipple instrument. Both of these have detected high-energy gamma rays from the Galactic Centre in the past (observations from 1995-2002), though not with the same precision as H.E.S.S, and they were unable to pinpoint the exact location as H.E.S.S. has now done, making it harder to deduce the source.
These previous results have different characteristics to the H.E.S.S. observations.
It is possible that the gamma-ray source at the Galactic Centre varies over the timescale of a year, suggesting that the source is in fact a variable object, such as the central black hole.

A novel method of optical data storage could soon be used to hold a terabyte of data on a disk the size of a normal DVD, say researchers at Imperial College London, UK, said the New Scientist.
Information is encoded on a normal DVD in the form of microscopic indents on the surface of the disk. The presence or absence of an indent corresponds to a binary piece of information--a '1' or a '0'.
Indents are detected by beaming light onto a disk with a laser and measuring the amount of light that bounces back.
Using tracks embedded at several depths within a disk, it is possible to store more data on the highest capacity disks. Multi layer DVDs hold about 16 gigabytes of data, which equals about 8 hours of high quality video.
But the researchers realized that the polarity of light might also be used to encode information.
They developed a type of disk that incorporates angled ridges within the pits in order to subtly alter the polarity of the light that gets reflected.
This can be used to store 10 times' more data than is currently possible, they say.
Using the technique, the researchers think it should be possible to create disks capable of holding 250 gigabytes in a single layer. This is enough to store 118 hours of video, which could allow every episode of long-running television shows to be put on one disk. Using a four-layer disk would mean a terabyte could be stored.
In the new system, light polarised in a single direction is beamed onto the surface of the disk. Some bounces back with a polarity at 90 degrees to that of the original beam. By measuring how much light comes back in each of the two directions, it is possible to work out the precise angle of the slope.

Planetary wind consists of volatile materials that are energized, ionized and accelerated by the solar wind as it penetrates Mars' atmosphere.

The solar wind has a much bigger impact on Mars than previously thought according to the first results from the ASPERA-3 instrument on Mars Express, PysicsWeb.org said.
Rickard Lundin of the Swedish Institute of Space Physics and an international team of co-workers have found that the solar wind--a supersonic plasma of charged particles that flows from the Sun--can penetrate deep into the atmosphere of Mars.
One consequence of this is that water and other volatile molecules could escape from the planet.
Many theories have been put forward to explain how Mars changed from being a warm, wet planet to a cold, dry one. Recently it was estimated that a volume of water equivalent to a planet-wide ocean with a depth of between 14 and 34 meters could have escaped from the red planet during the past 3.5 billion years. Unlike the Earth, Mars does not have a magnetic shield to protect it from the solar wind, so particles from the Sun may have played a crucial role in shaping the Martian atmosphere.
Lundin and colleagues made in situ measurements of the solar wind flowing towards Mars, and the "planetary wind" flowing away from the planet. The planetary wind consists of volatile materials that are energized, ionized and accelerated by the solar wind as it penetrates Mars' atmosphere.
They found that the solar wind could penetrate as deep as 270 kilometers above the Martian surface. Moreover, they found that positively charged hydrogen and oxygen ions flowing away from the planet could have energies as high as several keV at low altitudes, which means that they have enough energy to escape. According to Lundin and co-workers, the combined escape of hydrogen and oxygen ions might be evidence for a slow dehydration of Mars.

University of Pittsburgh researchers have synthesized a simple molecule that not only produces perfectly uniform, self-assembled nanotubes but creates what they report as the first "nanocarpet," whereby these nanotubes organize themselves into an expanse of upright clusters that when magnified a million times resemble the fibers of a shag rug, brightsurf.com said.
Moreover, unlike other nanotube structures, these tubes display sensitivity to different agents by changing color and can be trained to kill bacteria, such as E. coli, with just a jab to its cell membrane.
"In these nanotube structures, we have created a material that has the ability to sense their environment. The work is an outgrowth of our interest in developing materials that both sense and decontaminate chemical or biological weapons," said senior author Alan J. Russell, Ph.D., professor of surgery at the University of Pittsburgh School of Medicine and director of the university's McGowan Institute for Regenerative Medicine.
The researchers thought that by combining a chemical structure called a quarternary ammonium salt group, known for its ability to disrupt cell membranes and cause cell death, with a hydrocarbon diacetylene, which can change colors when appropriately formulated, the resulting molecule would have the desired properties of both biosensor and biocide.
Remarkably, in addition to being able to kill cells, the resulting reaction mixture had the ability to self assemble into beautiful nanotubes of uniform structure.

People who live in sprawling communities tend to suffer more health problems, according to the first study to document a link between the world of strip malls, cul-de-sacs and subdivisions and a broad array of ailments, said the Washington Post.
The study, which analyzed data on more than 8,600 Americans in 38 metropolitan areas including the Washington regions found that rates of arthritis, asthma, headaches and other complaints increased with the degree of sprawl.
Living in areas with the least amount of sprawl, compared with living areas with the most, was like adding about four years to people's lives in terms of their health, the study found.
The increase in health problems is presumably due to the fact that sprawls discourages physical activity, increasing the chances of being overweight or obese. In addition, sprawling communities tend to have more air pollution, Sturm said.
Although some researchers have speculated that the social isolation that can occur in sprawling communities may also lead to more mental health problems, such as depression, the new study failed to find that link.