Thursday, 24 December 2015

Exploring the Universe

On a fine bright night when you look up at sky, it seems to be studded with stars. Little do you realise that each of stars is far bigger than the earth on which we live. Some of the larger ones have been estimated to be many millions of times the size of the earth. These stars are not scattered regularly in space; they occur in clusters, better described as galaxies or nebulas. Each galaxy may contain as many as 100 million stars. It is believed that the earth's own galaxy(the Milky Way) alone containsas many as 100,000 million stars.
The star appear small to us even though a telescope because they are so far away. The light from nearest star travelling at the speed of light (i.e 186,000 miles per second) takes something like four years to reach us. A ray of light from sun takes about 8 minutes to reach the earth. Light takes only a second to reach us from the moon.

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