Across
- 4. A giant ball of superheated gas, or plasma, composed of hydrogen and helium.
- 6. The Greek philosopher who was one of the first supporters of the geocentric model
- 7. Another name for Earth's orbit around the Sun
- 8. Earth's only natural satellite
- 12. This comet first appeared in 1758 and continues to appear approximately every 75 years.
- 13. A pattern or group of stars that people imagine represents a figure, animal or object.
- 15. Stars are made up of hydrogen and _________.
- 17. During this season will you see the constellation Orion in the western sky
- 20. The word planet means ______________.
- 22. Earth-centered
- 23. Ursa major means ____________.
- 25. Pieces of space rock that hit the Earth's surface
- 27. This astronomer discovered moons around Jupiter, which showed that not everything in the sky travels around Earth.
- 28. Earth's revolution around the Sun causes __________.
- 30. Pieces of rock and/ice that have broken off of asteroids, comets, moons, and planets
- 31. A body that orbits a a planet.
Down
- 1. There are ____ constellations.
- 2. What Aryabhata used to come up with his ideas about how objects moved in space.
- 3. The astronomer who said the moon and planets shine because they reflect light from the Sun.
- 5. Proposed that Earth's rotation and revolution around the sun explained the observed movements of the stars and planets
- 9. Galileo discovered that this planet goes through phases like the moon does, meaning it must orbit the sun, not the Earth.
- 10. Sun-centered
- 11. Another name for a meteor.
- 14. The narrow band in the sky that contains the orbits of all the planets
- 16. In Ptolemy's geocentric model, the planets made small circles called _______ as they moved along their orbits.
- 18. Determined that the orbit of each planet is an ellipse rather than a perfect circle
- 19. An object that orbits the sun, is large enough to have become rounded by its own gravity, and has cleared the area of its orbit of any debris.
- 21. These two planets never appear far from the sun in the sky
- 24. Large, dirty space snowballs that develop a long tail of light as they approach the sun
- 26. An oval shaped orbit of the planets around the sun
- 29. Pieces of space rock that burn up as then move through the Earth's atmosphere.