Across
- 1. People trained to travel and work in space.
- 7. A tool that spreads light into colors so scientists can learn what stars and other objects are made of.
- 9. whatever carries the wave
- 10. A back and forth motion that repeatedly follows the same path
- 14. a single rise or depression in a series of waves
- 15. The planet we live on; the only known planet with life.
- 16. Very dense, fast-spinning stars that give off regular pulses of radio waves, like a cosmic lighthouse.
- 18. An American scientist known as the father of modern rocketry; he built and launched the first liquid-fuel rocket.
Down
- 2. An object that moves around a planet; it can be natural (like the Moon) or man-made (used for communication or weather).
- 3. The largest planet in the solar system; a gas giant with many moons.
- 4. (1564-1642)the first astronomer to make extensive use of a telescope to study the heavens
- 5. The largest moon in the solar system; it orbits Jupiter.
- 6. The second planet from the Sun; very hot and covered with thick clouds.
- 8. A device to make distant objects appear clearer, brighter, or closer
- 11. low point in a wave
- 12. Saturn’s largest moon; it has a thick atmosphere.
- 13. The planet closest to the Sun; very hot during the day and very cold at night.
- 17. A gas giant known for its large, beautiful rings.