ASTRONOMY FOR KIDS

The first type of nebulae we are going to explore are called Emission Nebulae, because they emit their own light. 

How do they emit light?
They glow red or pink as they expel extra energy which they get from nearby stars. 

Bright stars inside the clouds charge hydrogen gas with extra energy.  The hydrogen in these clouds does not like to be charged and so they get rid of the extra energy by emitting it  in the form of red light. 

The cloud itself is actually glowing.  Just like a neon sign. 

Remember:  A red or pink nebulae is called an Emission Nebulae and glows because it is getting rid of the extra energy given to it by nearby stars.

A blue relfection nebulae is completely different from an emission nebulae.  This is because rather than emitting their own light, they are reflecting the light of the stars around them. 

Why are they blue?
Reflection nebulae are blue for the same reason our sky is blue.  They reflect the light of a star.  Our sky is reflecting the light of the sun.

When light passes by a particle of dust, the blue color in that light is scattered , while the rest of the colors in the light are allowed to travel undisturbed.  This blue light travels around the cloud bouncing off of dust particle after dust particle until it eventually escapes the cloud and reaches our eyes.

Remember:  A blue nebulae is called a reflection nebulae.  They scatter the blue  light from nearby stars while the rest of the colors are allowed to pass through the cloud undisturbed.  Eventually the blue light escapes the cloud and travels to our eyes. 

Although this third type of nebulae is called a planetary nebulae, it actually has nothing to do with planets.  A planetary nebulae is formed when a dying sun sized star begins to shed its outer layers. 

When the Sun begins to die it will expand, and become what is called a giant star.  It will grow so large that it may engulf the Earth.  After millions of years as a giant star the sun will again shrink down to its normal size.  As it shrinks much of its surface layers will be shed leaving behind a beautiful ring. 

This ring is only visible for about 50,000 years.  Over time the nebulae mixes into surrounding space eventually becoming too thin to see.

A Bok Globule is different than the other types of clouds we have been learning about.  Bok Globules are very dense.  This means that there is a lot of dust and gas close together inside of the cloud.  There is so much dust and gas that it blocks out all the light behind it.  In the picture to the right, you can see two nebulas.  First you can see the blue reflection nebulae in the back ground.  In front of the reflection nebulae is a dark bok globule blocking the view.