1. Nebulae Space clouds

2. What is a Nebula? A nebula is an interstellar cloud of 90% hydrogen, 10% helium, & trace amounts of heavier elements Nebulae are the basic building blocks of our universe, and contain the elements from which stars and solar systems are made. They are the biggest things in our galaxy. Ranging from a dozen to hundreds light-years across.

3. Different Types of Nebulae There are five different types of Nebulae: 1. Emission 2. Reflection 3. Dark 4. Planetary 5.Supernova Remnants.

4. Emission Nebulae Usually red Are clouds of high temperature gas. Energized by ultraviolet light from nearby stars they emit radiation Usually the sites of recent and ongoing star formation.

5. Reflection Nebulae Usually blue Clouds of dust that reflect the light from a nearby star. Usually found at “star formation” sites and are mostly found near Emission Nebulae Sometimes referred to as Defuse Nebulae.

6. Dark Nebulae Are so dense they block the light coming from whatever is behind it Dust grains located at the coldest densest parts of the molecular cloud block the light.

8. Planetary Nebulae Shells of gas usually thrown out when stars similar to our Sun die. Are usually one light-year across Once mistaken for planets they have nothing to do with them. Have very short lives, only lasting a few ten thousands years. The ultraviolet radiation from the core ionizes the ejected layers and make them emit light.

9. Supernova Remnants Created when a massive star ends its life in a supernova. They have a chaotic appearance