1. is the galaxy that contains the Earth, the Sun, and the solar system. 2 is twinkle of light 3. is a scientisi who studies space and the Universe beyond Earth. is the distance that light travels in one year, about 6 billion miles, 5. is the branch of science that studies space. 6. _remain in a constant position in the sky, used for navigation 7. made up of this constellation's seven brightest stars, form a shape that looks like a dipper. 8. is a very light gas and one of the most abundant gases in the Universe. is a group of stars in the night sky forming patterns that look like animals, objects, or characters. 10. is to bend as you move from one medium to another. 11. A collection of billions of stars and other maller held together by gravity. 12. A cloud of dust and gas found in interstellar space. called "star nurseries" because stars are created there. 13. A force that pulls matter together. 14. A gas that is lighter than air. 15. The constellation Ursa Minor (Little Bear). 16. Alarge constellation in the northem sky, also called a hunter. 17. A space telescope launched into low Earth orbit in 1990 that have helped scientists to understand our Universe better. 18. Our planet Earth and the sun belong to the galaxy 19. is the amount of light that a star radiates. 20. stars tend to be redder in color, while hotter stars have a bluer appearance.