Nebulas are diverse in nature; and can be dense, or very wide, thinner than the vacuum on Earth, and coolest or hot.
The shapes and sizes of clouds we see everyday take a tour into the world of imagination. Beautiful colours and breathtaking sizes of clouds remain in the universe too. They are generally called “Nebula”: a home where new stars take birth!
Various chemical compounds such as dust, Helium, Hydrogen and ionized gases form giant clouds. These clouds are are known as 'Nebulas'. The name is derived from the Latin word for ‘cloud’ or ‘fog’ i.e. Nebula. Mesmerising colours of Nebula are a representation of gases present inside it. It includes Hydrogen (Orange), Nitrogen (Red), Sulphur (Pink), and Oxygen (Green) in its expanding cloud. Whereas, the shades of colours depends on the temperature as well as the density of the gas. The colour of the nebula may change completely depending on the temperature though the same gas is present inside it.
Nebulae are light years away from the Earth. The closest one is 700 light years away. Only one, ‘Orion Nebula’, can be seen with naked eyes from the Earth. Nebulae are diverse in nature. They can be dense, or very wide, thinner than the vacuum on Earth, and coolest or hot. The stars inside Nebulae make them shine. The hotness of stars/ planets inside radiate waves. This makes them visible to us.
How stars are formed inside Nebula?
Deep inside Nebula, it is formed of giant clouds made up of dust and different gases. The turbulence deep within these clouds begins to give rise to knots of sufficient mass. Thus, clouds and dust start collapsing with its own gravitational attraction. The heat is produced at the centre due to collision and 'protostar' is formed. As clouds collapse, with time, a dense, hot core forms. It begins to gather dust and gas to give birth to a star. Not all formations end in new star. But, they can turn into planets, asteroids, comets or may remain as dust only.
The present highly advanced telescopes in space have been successful in taking pictures of these far distant Nebulae. Few examples are Butterfly, Carina, Cat’s eye, Red Square, Eagle also known as Pillars of creation, Crab Nebula. NASA has launched over 50 telescopes. Most of them independently explore the deep space. ISRO has recently launched its first dedicated multi-wavelength space observatory, “Astrosat” in September, 2015.
Let’s hope a journey in deep space with upgraded instruments will definitely reveal the beauty of the universe constantly to amaze us!