By Roger Highfield, Science Editor
Nasa is about to launch a powerful space observatory that will reveal the most violent phenomena in the universe. chinageo.com
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The $690 million Gamma-Ray Large Area Space Telescope (GLAST) will detect gamma rays, the highest-energy form of light. chinageo.com
The "gamma-ray sky" is spectacularly different from the one we perceive with our own eyes, which respond to a relatively narrow range of colours. The telescope's high-energy gamma-ray "eyeglasses" will reveal hidden wonders, opening our minds to new possibilities and discoveries, expanding our understanding of the universe and our place in it.
This view will reveal new features of the most violent events in the universe to help astronomers tackle a wide range of questions, including supermassive black-holes, pulsars, the origin of cosmic rays, and searches for tell tale signs that we need new physics.
Glast is scheduled - clouds permitting - to launch on a United Launch Alliance's Delta II Heavy rocket at Cape Canaveral Air Force Station with a launch window from 11:45 am to 1:40 pm EDT, or 3:45pm to 5:40pm GMT today, Wednesday, June 11.
ChinaGeo
"There's a broad science community that's anxiously awaiting this launch," said Steven Ritz, a Glast project scientist and astrophysicist at Nasa's Goddard Space Flight Centre. ChinaGeo
"It's about to open up the universe to us in new and exciting ways," in particular the "last unexplored regions of the electromagnetic spectrum," Ritz said.
With Glast, astronomers will explore the most extreme environments in the cosmos. chinageog.com
"Active galactic nuclei will be Glast's bread and butter," added Ritz. "There are guaranteed results." 中_国_地_理_网
Active galactic nuclei, or AGN for short, are galaxies with extraordinarily luminous cores powered by black holes containing millions or even billions of times more material than our Sun.
中国地理网
As gas is trapped by a monster black hole's gravity, it starts to spiral down the universe's ultimate drain. Before the gas crosses the black hole's outer boundary (the event horizon) - beyond which nothing can escape - the material generates a vast outpouring of electromagnetic radiation.
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In the most luminous AGN, the visible light exceeds the combined output of an entire galaxy's worth of stars, even though the light-emitting area is only about the size of our solar system. c.h.i.n.a.g.e.o
Physicists will be able to study subatomic particles at energies far greater than those seen in ground-based particle accelerators, in the never ending quest to find evidence of new laws. And cosmologists will gain valuable information about powerful explosions called gamma-ray bursts, and the birth and early evolution of the universe.
chinageog.com
The identity of dark matter - the mysterious stuff that makes up about 22 per cent of the universe's energy contents - continues to elude scientists decades after they first inferred its existence. CHINAGEO
The leading candidate that might explain the fundamental make-up of dark matter is a hypothetical particle called the weakly interacting massive particle, or Wimp, and the hope is that Glast may confirm this is the case.
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For the mission, Nasa is teaming up with the US Department of Energy and institutions in France, Germany, Japan, Italy and Sweden.
Originally scheduled to lift-off May 16, the launch has been pushed back a number of times due to delays in completing the telescope as well as problems with the spacecraft.