UNIVERSE AND MYSTERIES.
When I look upon the stars, the sky, the moon and the sun, many questions come to mind like how big are they?, how did they originate? , how long their life is?. For many years, human beings have been trying to find answers to these questions, but the answers to many of these questions are still unknown. Initially telescopes were used, but not enough information was obtained through telescopes. Then ,with advancement in technology, scientists started using satellites, rockets and space shuttles. As a result we lot of information was obtained and a separate branch called astronomy came into existence to do research and study the universe.
Astronomers have found that the universe consists of galaxies, black holes, comets, planets, satellites. Stars contribute to the formation of galaxies and black holes. Galaxies are clusters of millions or trillions of stars having mass trillion times the mass of our sun. Galaxies have different shapes like spiral, elliptical, irregular. Our galaxy is the Milky Way and is spiral in shape. The Sun is one of the 100 million stars in the Milky Way. From this, we can imagine the vastness of the milky way and hence the universe. .
Black holes are mysterious components of universe. A black hole is a region in space from which nothing can escape, even light. Their existence was confirmed just a few years ago through X-rays. Black holes are thought to form from stars or other massive objects if and when they collapse from their own gravity to form an object whose density is infinite. If the star's final mass exceeds much beyond 2 solar masses, there is no outward force that can resist gravity. The core continues to collapse to a critical size or circumference beyond which there is only one fate: to form a black hole. .
Astronomers believe that we have been able to see only 5% of the universe due to its vastness.