A nebula is a large cloud of gas and dust in space. It is the birthplace of stars and planets.

The three main types of nebulas are emission nebulas, reflection nebulas, and dark nebulas.

An emission nebula is a nebula that emits its own light. This light is caused by the ionization of the gas in the nebula by ultraviolet radiation from nearby stars.

A reflection nebula is a nebula that reflects light from nearby stars. This light is scattered by the dust particles in the nebula.

A dark nebula is a nebula that absorbs light from nearby stars. This makes it appear dark when viewed against the background of the night sky.

A planetary nebula is a nebula that is formed when a star dies. It is the result of the star's outer layers being expelled into space.

A supernova remnant is a nebula that is formed when a star explodes. It is the result of the star's core collapsing and releasing a huge amount of energy.

The Orion Nebula is an emission nebula. It is one of the brightest nebulas in the night sky and is visible to the naked eye.

The Crab Nebula is a supernova remnant. It is the result of a supernova that was observed in 1054 AD.

The Horsehead Nebula is a dark nebula. It is a small, dark cloud of gas and dust that is shaped like a horse's head.

The Ring Nebula is a planetary nebula. It is the result of a star's outer layers being expelled into space.

The Eagle Nebula is an emission nebula. It is one of the most famous nebulas in the night sky and is home to the Pillars of Creation.

The Carina Nebula is an emission nebula. It is one of the largest and brightest nebulas in the night sky.

The Sombrero Galaxy is a galaxy. It is one of the most famous galaxies in the night sky and is visible to the naked eye.