1. Our SOLAR SYSTEM and beyond

6. Phases of the Moon

8. Inner Planets Outer Planets Asteroid Belt Located between Mars and Jupiter, The asteroid belt separates the Inner Planets from the Outer Planets. Planets closest to the Sun are smaller and mostly solid (formed from heavy, rocky materials). Planets farthest from the Sun are larger and formed mainly of gases.

18. CAST OF GALAXIES… THE 3 MAIN TYPES OF GALAXIES. Elliptical galaxies are shaped like ellipses (stretched circles). They are divided into eight types: E0-E7 depending on how elliptical they are. E0 ellipticals are nearly circular, while E7s are very stretched out. Elliptical galaxies are made up of mostly old stars, and do not have much gas and dust. There is very little new star formation in these galaxies. Elliptical galaxies also come in many sizes. The largest galaxies we see are elliptical, but, elliptical galaxies can also be small. About 60% of all galaxies are elliptical. Irregular galaxies have no particular shape. They are among the smallest galaxies and are full of gas and dust. Having a lot of gas and dust means that these galaxies have a lot of star formation going on within them. This can make them very bright. The Large and Small Magellan Clouds are examples of irregular galaxies. They are two small galaxies which orbit around our own Milky Way galaxy. About 20% of all galaxies are irregulars. Spiral galaxies get their name from the shape of their disks. In a spiral galaxy, the stars, gas and dust are gathered in spiral arms that spread outward from the galaxy's center. Spiral galaxys are divided into three main types depending on how tightly wound their spiral arms are: Sa, Sb and Sc. Spiral galaxies have a lot of gas, dust and newly forming stars. Since they have a lot of hot, young stars, they are often among the brightest galaxies in the universe. About 20% of all galaxies are spirals. We live in a spiral galaxy called the Milky Way.

19. THE MILKY WAY… Our home in the stars… It takes the sun 200 million years to make one rotation around the center! The Milky Way is the galaxy in which we live. It is a spiral shaped galaxy that contains about 200 billion stars, including our Sun. It is about 100,000 light-years across and about 10,000 light-years thick. If you are at a place which has a very dark night sky, you can sometimes see the Milky Way as a thick band of stars in the sky. We live near the edge of the Milky Way.

20. A constellation is a group of stars visible within a particular region of the night sky. Some were named after animals and some mythological characters. Some constellations were named after some scientific instruments. Constellations can be viewed after sunset and before sunrise. Also, as the earth turns you can see different constellations.