2. The origins of the planets

6. Star nurseries in the constellation Sagittarius

7. Orion Nebula is part of a large gas and dust cloud located in the Orion Constellation. It is one of the closest stellar nurseries to us at about 1,500 light years. The whole cloud easily spans over several hundred light years. Here you can see recently formed stars as they blink on in the interior of the dust cloud. Orion Nebula, Star Nursery ?

8. Evidence of Planetary Systems  What discovery did IRAS make in 1983?  Starbust Galaxies  Milky Way Galaxy Core

9.  What other discoveries have been made since then?  Early stage planetary formations

10. Formation of the Solar System  In its early stages, our solar system was part of a Nebula consisting mainly of Gas and Dust  Definition of nebula:  A diffuse mass of interstellar dust or gas or both, visible as luminous patches or areas of darkness depending on the way the mass absorbs or reflects incident radiation.

11.  At the time our Sun formed, scientists think that smaller clumps of matter began to Combine in the outer regions of the solar nebula. Attracted by the force of Gravity, the clumps formed Planets. This theory explains the formation of the Solar System. These planets are composed mainly of Gases, which are the same gases that make up our Atmosphere.

12. Stages in Planetary Evolution 1. Planetesimals … small bodies formed from dust and gas eddies

13. Stages in Planetary Evolution 2. Protoplanets 9 or 10 formed from plaetesimals

14. Stages in Planetary Evolution 3. Planets formed by combining protoplaents swept up by gravitational attraction

15. Our Solar System

16. Edge-on view of a spiral galaxy. Our galaxy, the Milky Way, would look very much like it to an outside visitor

17. Our galaxy, the Milky Way