NASA discovers alternate source of cosmic energy

Friday, November 21, 2008 at 4:11 am

The American space agency NASA has found an alternate source of cosmic energy from a previously unidentified particle near the solar system, researchers say. The discovery published in the latest issue of science journal ‘Nature’ was the result of a study carried out by the Advanced Thin Ionisation Calorimeter (ATIC) collaboration led by scientists at Louisiana State University, Baton Rouge.

The new findings show an unexpected surplus of cosmic ray electrons at very high energy — 300-800 billion electron volts — that must come from a previously unidentified source or from the annihilation of very exotic theoretical particles used to explain dark matter, they say.

“This electron excess cannot be explained by the standard model of cosmic ray origin,” said John P Wefel, principal investigator of the ATIC project and a professor at Louisiana University.

“There must be another source relatively near us that is producing these additional particles,” Wefel added.

The researchers believe that the new energy source must be within the range of about 3,000 light years from the sun. It could be an exotic object such as a pulsar, mini-quasar, supernova remnant or an intermediate mass black hole.

“Cosmic ray electrons lose energy during their journey through the galaxy,” said Jim Adams, ATIC research leader at NASA’s Marshall Space Flight Centre in Huntsville.

“These losses increase with the energy of the electrons. According to the measurement by our instrument, these energy losses suppress the flow of particles from distant sources, which helps nearby sources stand out.”

The scientists point out, however, that there are few such objects close to our solar system.

“These results may be the first indication of a very interesting object near our solar system waiting to be studied by other instruments,” Wefel said.

An alternative explanation is that the surplus of high energy electrons might result from the annihilation of the exotic particles put forward to explain dark matter.

In recent decades, scientists have learned that the kind of material making up the universe around us only accounts for about five per cent of its mass composition.

Close to 70 per cent of the universe is composed of dark energy (called so because its nature is unknown). The remaining 25 per cent of the mass acts gravitationally just like regular matter, but does little else, so it is normally not visible.

The nature of dark matter is not understood but several theories that describe how gravity works at very small quantum distance predict exotic particles that could be good dark matter candidates.

“The annihilation of these exotic particles with each other would produce normal particles such as electrons, positrons, protons and antiprotons that can be observed by scientists,” said Eun-Suk Seo, ATIC lead researcher at the University of Maryland, College Park.

The 4,300-pound ATIC experiment was designed to be carried to an altitude of about 124,000 feet above Antarctica using a helium-filled balloon. The goal was to study cosmic rays that otherwise would be absorbed into the atmosphere.

ATIC is an international collaboration of researchers from various universities of US, China, Russia and Germany.

The collaboration is supported by NASA and space flights are conducted under the auspices of the Balloon Program Office at NASA’s Wallops Flight Facility in Virginia by the staff of the Columbia Scientific Balloon Facility.

(With Inputs From agencies)

( This post is from an independent writer. The opinions and views expressed herein are those of the author and are not endorsed by APakistanNews.Com.)

NASA discovers alternate source of cosmic energy

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