Why are Gamma Ray telescopes placed in Space?
Fermi Gamma ray telescopes do not possess any sort of mirrors but they have a special type of sensors to monitor and note the energy and direction of Gamma rays. These telescopes can identify gamma rays having energy in the range of 10 KeV to 300 KeV. They can scan at least twenty percent of the sky at a time and hav the ability to cover scanning the total sky every three hours.
The gamma ray telescopes on the ground measure the gamma rays indirectly as these rays cannot pass through earth’s atmosphere. A shockwave of electromagnetic nature is generated when the gamma ray collide with the proton or neutron in the atmosphere. The resulting Cherenkov blue radiation is recognized by the ground- based telescopes.
At high frequencies or high energy, gamma rays will start a lot of showers by hitting the air in the upper atmosphere and the related resultant particles radiate Cherenkov radiation which can reach the ground level. The sensor or detector that is placed at any region in the celestial light can identify the size and type of hits on the camera and can create on its own, the energy and direction of the showers and the causal particle of the showers. The area of the detector can be the size of the total light available which is around 100,000 square meters.
Gamma rays can travel very long distances in the universe but are absorbed by the Earth’s atmosphere. These rays are produced by the very hottest regions of the universe. They are known to be released from supernova explosions, or decay of radioactive materials in space. Neutron stars, pulsars and black holes are also part of the sources of gamma rays in the space.
The astronomy of gamma rays could not develop until it is placed in the space above all, outside the atmosphere in order to capture the gamma rays and identify its source in the universe. This cannot happen in the presence of an obstruction called atmosphere. These telescopes make use of a process called Compton scattering to detect the gamma ray source.