Explain the principle behind functioning of space telescope. Also explain why world‘s largest telescopes are built on higher elevations. (150 Words)
Various telescopes work by capturing a specific light in the broad spectrum of electromagnetic radiation (visible light, infrared, x-rays, microwaves etc.) either through reflecting or refraction. Principles of Space telescope are not different from ground telescopes. It can be a reflecting or refracting telescope basic principle it to
- Collect more and more light and
- Converge it to the focal point
e.g. Hubble telescope which uses Cassegrain reflector, it has two mirrors, one primary concave mirror and another convex secondary mirror. So light entering the telescope is collected by primary mirror and reflected onto secondary convex mirror which converges it on the sensors.
Since the earth’s atmosphere distorts, scatters, absorbs and blurs the light entering it so an ideal place to capture light would be out of earth’s atmosphere or from high altitudes where atmosphere is less dense. That is the reason why ISRO has it observatory in Himalayas to minimize these atmospheric effects