Thread: GLAST Satellite to Reveal Unseen Universe

This thing is launching next month:



It will be detecting, for the first time, very high energy gamma rays at the extreme end of the electromagnetic spectrum that can only be emitted by extreme processes, perhaps even dark matter annihilating itself. By observing the cosmos, it will help explain the existence of new particles.

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It will also compare the speeds of high energy gamma rays, the more energetic of which might be slowed by sensitivity to the extremely small scale of a fabric of spacetime boiling with multidimensional "strings." This might bolster the existence of strings and string theory, the most successful attempt thus far to join quantum mechanics (on the sub-atomic scale) to gravity (on a cosmic scale).

It will also reveal a completely hidden universe, a night sky lit up with jets from super-massive black holes that lurk at the center of galaxies



with radii wider than the orbit of Mars containing billions of solar masses, that might themselves eventually evaporate and collapse, leaving hitherto unseen gamma traces.




Found a decent explanation from a German website:

Gamma radiation, the most energetic form of radiation in the electromagnetic spectrum, is invisible to the human eye. Among the entire electromagnetic spectrum, only the narrow band of optical wavelengths (to say: visible light) is directly accessible by the human eye. In order to observe gamma rays, one needs to develop and apply dedicated detector techniques, similarily as necessary to access other wavebands invisible for the human eye like radio waves, infrared and ultraviolett radiation and X-rays. Because the physical generation processes of electromagnetic radiation at other wavelengths are different, also the detection principles differ with the energy of the radiation.




What are the scientific goals of the GLAST mission?



Because high energy gamma radiation could only be produced unter extreme conditions, GLAST will study the most energetic astromonical objects in the Universe. In the energy range of GLAST, the Universe is largely transparent to gamma rays. This way especially energetic sources near the edge of the visible Universe can be investigated. There is good reason to expect that GLAST will see known classes of sources deep of the early universe. Gamma rays point back to their sources, unlike cosmic rays, which are deflected by magnetic fields. GLAST will study such exotic objects like heavy black holes and neutron stars, but will also investigate the life cycle of stars, and trace the dark components of matter. But also our own Galaxy, the Milky Way, is a source of gamma radiation, which is generated by interactions of energetic particles of the cosmic radiation and interstellar matter. And even our Sun generate gamma rays at its surface during flare outbursts . And with the capabilities of the GLAST instrument there is a good chance given for unexpected and perhaps even more fascinating discoveries!

Even more Astrophysics with GLAST ?

Why GLAST has be a satellite experiment?

There are a few hurtles astronomers must over come in order to detect gamma rays. For one, there are not a lot of gamma rays out there to be detected. Scientists must be able to wait a long time to get enough information from a source. Another is the fact that most gamma rays are absorbed by the Earth's atmosphere. This is good since gamma rays are extremely energetic and harmful to life on Earth, but if you want to observe gamma-ray sources from the Universe it can pose a problem. Therefore gamma-ray observations are generally done with high-altitude balloons or satellites launched into space, above the atmosphere.

From Nasa:

"WHAT DOES GLAST" STAND FOR?

Gamma-ray Large Area Space Telescope

WHAT IS THE PURPOSE OF THE GLAST MISSION?

The Universe is home to numerous exotic and beautiful phenomena, some of which can generate inconceivable amounts of energy. GLAST will open this high-energy world. Astronomers will have a superior tool to study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds. Physicists will be able to search for signals of new fundamental processes that are inaccessible in ground-based accelerators and observatories.

WHAT ARE GLAST'S MAIN MISSION OBJECTIVES?

• To understand the mechanisms of particle acceleration in active galactic nuclei (AGNs), neutron stars, and supernova remnants (SNRs).
• Resolve the gamma-ray sky: characterize unidentified sources and diffuse emission.
• Determine the high-energy behavior of gamma-ray bursts (GRBs) and variable sources.
• Probe dark matter and the early Universe.

WHAT KINDS OF THINGS WILL GLAST STUDY?

1. Blazars and Active Galaxies + Learn more

2. Gamma-ray Bursts + Learn more




3. Neutron Stars + Learn more




4. Cosmic Rays and Supernova Remnants + Learn more





5. Milky Way Galaxy + Learn more




6. The Gamma-ray Background + Learn more



7. The Early Universe + Learn more
8. Solar System: Sun, Moon, and Earth + Learn more
10. Dark Matter + Learn more
11. Testing Fundamental Physics + Learn more
12. Unidentified Sources and the Unknown + Learn more

WHAT'S NEW AND REVOLUTIONARY ABOUT THIS MISSION?

GLAST is the first imaging gamma-ray observatory to survey the entire sky every day and with high sensitivity. It will give scientists a unique opportunity to learn about the ever-changing Universe at extreme energies. GLAST will detect thousands of gamma-ray sources, most of which will be supermassive black holes in the cores of distant galaxies. GLAST uses Einstein's principle of E = mc 2 to convert gamma rays into matter in order to track their cosmic origins. GLAST observations may reveal signatures of new physics, including the potential to identify the unknown particle which may compose dark matter.

WHAT ARE SOME OF THE QUESTIONS GLAST HOPES TO ANSWER?

How do black holes accelerate jets of material to nearly light speed? What is the mysterious dark matter? What mechanism produces the stupendously powerful explosions known as gamma-ray bursts? How do solar flares generate high-energy particles? How do pulsars work? What is the origin of cosmic rays? What else out there is shining gamma rays?