Telescopes

How does a telescope see in the dark? -

A telescope is a light budget. It collects the light from the objects in space using either a lens or, more usually, a mirror. A main mirror reflects the light to a smaller one, which brings the light to smaller one, which brings the light to a focus where an image of the object is formed.

 

Types of telescope -

Refracting telescope- Uses a large lens to refract, or bend, the light forms an image of a distant object.

Reflecting telescope - Uses a large curved mirror to pick up the faint light from distant stars. 

Radio telescope - Captures invisible radio waves given out by stars and other objects in space.

Space telescope - Controlled by engineers on the ground, orbits Earth and works 24 hours day.

Fun Fact -

A batch of radio telescopes known as Allen Telescopes Array listen out for signs of alien life. Together they will survey a million for radio signals generated by extra-terrestrial intelligence.  

Bonus fact - 

The largest single radio telescope is the 305-m (1,000-ft) dish at Arecibo, Puerto Rico. Built in a hollow in the island's hills, it faces different parts of the sky as the Earth turns. 

-Keva