Nebula
What is a nebula? How are nebulae formed? What are the types of nebulae, and how do they differ from each other? What is the shape of nebulae, and how do they look? Read on to know more! WHAT IS A NEBULA? A nebula is an interstellar cloud of hydrogen, helium, and other ionized gases(gases that carry a positive or negative charge). A nebula can also consist of plasma( state of matter wherein an atom gets so much heated that it's orbiting electrons are thrown out of their shells. They are super-ionized). All this makes nebula quite bright. Below is a picture showing a nebula. Helix nebula I know it looks like some weird eye-ball from horror movies, but that's how 'Helix Nebula' ( Planetary nebula) looks like (I have talked more about types of nebulae later in this article). Nebulae have really low density. For example, think about this: If the earth magically transforms into a nebula of the same size that of earth, it would weigh just a few kilogram...