Space Nebulae & Black Holes

Nebula Derived from the Latin word for "clouds". Nebulae are the basic building blocks of the universe They contain the elements from which stars and solar systems are built. Most nebulae are composed of about 90% hydrogen, 10% helium, and 0.1% heavy elements such as carbon, nitrogen, magnesium, potassium, calcium, iron.

Types of Nebulae

Emission Nebula A cloud of high temperature gas. Within this type of nebula, a star energizes the atoms in the cloud with ultraviolet radiation. As these atoms fall back to lower energy states, they emit radiation. The process is similar to that of a neon light. This causes the nebula to glow. Emission nebulae tend to be red in color because of the abundance of hydrogen

Reflection Nebula A cloud of dust and gas that reflects the light energy from a nearby star or group of stars. Reflection nebulae are frequently the sites of star formation. They usually tend to be blue in color because of the way that the light is scattered. Blue light is scattered more efficiently

Planetary Nebula A planetary nebula is a shell of gas produced by a star as it nears the end of its life cycle. They actually have nothing to do with planets. These nebulae were given this name because they often look like planets due to their round shape. The outer shell of gas is usually illuminated by the remains of the star at its center.

Supernova Nebula: Supernova remnants are created when a star ends it life in a massive explosion known as a supernova. The explosion blows a large amount of the star's matter out into space. This cloud of matter glows with the remains of the star that created it.

Nebulae...the stellar nurseries! Nebulae are often the sites of star formation. In fact, all stars, planets, and solar systems are formed from nebulae. A nebula may lie undisturbed for many millions or billions of years as it waits for just the right conditions to form stars.

Black Holes

A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes

Black Holes Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain.

Black Holes Another kind of black hole is called "stellar." Its mass can be up to 20 times more than the mass of the sun. There may be many, many stellar mass black holes in Earth's galaxy.

Black Holes Scientists think the smallest black holes formed when the universe began. Stellar black holes are made when the center of a very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space. Scientists think super massive black holes were made at the same time as the galaxy they are in.