A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases. Originally, nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way.
More than one nebula are called nebulae. Nebulae are the basic building blocks of the universe. They contain the elements from which stars and solar systems are built. They are also among the most beautiful objects in the universe, glowing with rich colors and swirls of light. Stars inside these clouds of gas cause them to glow with beautiful reds, blues, and greens. These colors are the result of different elements within the nebula. Most nebulae are composed of about 90% hydrogen, 10% helium, and 0.1% heavy elements such as carbon, nitrogen, magnesium, potassium, calcium, iron.
These clouds of matter are also quite large. In fact, they are among the largest objects in the galaxy. Many of them are dozens or even hundreds of light-years across. Nebulae have been divided into five major categories. These are emission nebulae, reflection nebulae, dark nebulae, planetary nebulae, and supernova remnants. Emission and reflection nebulae tend to be fuzzy in appearance and lack any noticeable shape or structure. They are also known as diffuse nebulae.
Horse Head Nebula
Helix Nebula
Cone Nebula
Eagle Nebula
Cat's Eye Nebula
Carina Nebula
Peony Nebula
Swan Nebula
Lagoon Nebula
Crab Nebula
Butterfly Nebula
Orion Nebula
Eskimo Nebula
Rosette Nebula
Reflection Nebula
Witch Head Nebula
Hourglass Nebula
Tarantula Nebula
Ant Nebula
Boomarang Nebula
California Nebula
Cat's Paw Nebula
Heart Nebula
Jellyfish Nebula
Flaming Star Nebula
Prawn Nebula
Cocoon Nebula
Dumbell Nebula
Iris Nebula
Fetus Nebula
Crescent Nebula
Little Ghost Nebula
Medusa Nebula
Snake Nebula
Rotten Egg Nebula
Pacman Nebula
Spirograph Nebula
Witch's Broom Nebula
The Wizard Nebula
