My Dark Sky

GLAST means Gamma-ray Large Area Space Telescope. So, in simple words, GLAST is a space telescope looking at gamma-rays.

Gamma-rays are electromagnetic waves just like the type of light we can see, but with much shorter wavelengths and hence much much higher energy. In fact, it is the highest energy photons in the electromagnetic spectrum, billions of times more energetic than visible light.

The problem is that most gamma-rays coming to Earth cannot penetrate through the Earth’s atmosphere and thus do not reach the ground. So one way to see them is to go to space, up above the atmosphere. That’s why we need a space telescope.

But why do we want to “see” gamma rays?

Our universe is an energetic place; it is full of violent events. These include exploding stars, merging neutron stars, black holes eating materials, streams of hot gas moving close to the speed of light… all these and many more violent events generate gamma-ray radiation.

Observing these extreme high-energy objects can help us to understand some of their mysteries:

• What is happening to produce this much of energy?
• What happens to the surrounding environment near them?
• 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?
• What else out there is shining gamma rays?
• What is the origin of cosmic rays?
• How do pulsars work?
• How do solar flares generate high-energy particles?
• How will studying these energetic objects add to our understanding of the very nature of the Universe and how it behaves?

There are so many questions waiting to be answered… and GLAST will help us answer a lot of these questions.

There are a couple of other interesting videos on GLAST at Bad Astronomy.

GLAST is scheduled to launch no earlier than this Thursday, June 5, during a window that extends from 11:45 am to 1:40 pm EDT. Once launched, GLAST will reside in a low-earth circular orbit at 565 km altitude. At this altitude, it will circle Earth every 90 minutes and will be able to view the entire sky in just two orbit, or about 3 hours. And this is important because the gamma-ray sky is constantly changing in stunning ways.

~ by thChieh on June 2, 2008.

Posted in Satellites & Spacecrafts
Tags: gamma ray burst, GLAST