2. A person who travels in space.

4. Frozen balls of ice, gas and rock orbiting the sun. Usually are irregular shapes. Also known as minor planets.

6. A scientist who studies space.

8. The study of space.

10. The gravity of a massive star or group of stars causes it to suck in on itself. This makes it so dense that not even light can escape its gravitational field.

12. A big chunk of rock, metal, and ice that orbits the sun. Has a tail of dust and gases called a coma.

14. Bunches of stars in the sky that look like pictures. Examples: Orion, Big Dipper, and Pegasus.

16. Immense systems containing billions of stars. Come in different shapes: spiral, elliptical, oval-shaped, and some are irregular. The universe may have 40 to 50 billion of them.

18. Fragments of comets, planets, moon, or asteroids that have broken off. Billions enter Earth’s atmosphere every day, but most disintegrate before reaching Earth.

20. Meteors that fall to Earth.

22. Our own spiral-shaped galaxy. Contains about 200 billion stars.

24. A natural satellite that goes around a planet.

26. To travel around a body on a path in space. For example: Earth ______s the sun.

28. A place equipped to observe space.

30. A body in orbit around the sun. There are nine in our solar system.

32. A body in orbit around a planet. Our moon is an example but some are also made by humans.

34. The sun, the nine planets that orbit it and the many satellites, asteroids and meteorites that are controlled by the suns gravitational pull.

36. Huge balls of hot gases. There are billions in the universe.

38. The closest star to the earth. The center of our solar system. Gives us heat in light.

40. An optical instrument used to view far away objects, such as planets and stars.