Across
- 2. the moon, sun, and the known planets—Mercury, Venus, Mars, and Jupiter—orbit Earth
- 3. The center of the Milky Way galaxy is a ___________ ___________.
- 9. large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions
- 15. The slow movement of the axis of a spinning body around another axis due to a torque acting to change the direction of the first axis
- 16. the duration of a complete rotation of the Milky Way, approximately 200 million years
- 17. the point at which the moon is farthest from Earth
- 18. the moon moves in a line directly between Earth and the sun, casting a shadow on Earth
- 19. Most of the lunar surface is made up of densely pitted, light-colored areas
- 24. an imaginary plane that connects Earth’s orbit with the celestial sphere
- 25. The very darkest part of the moon's shadow is cone-shaped
- 26. the shadow cast by the earth or moon over an area experiencing a partial eclipse
- 29. the time in January when Earth is closest to the sun
- 30. _________ are caused mainly by differences in how much the moon's gravity pulls on different parts of Earth.
- 31. When the moon is at a right angle to the sun
- 36. Earth and the other planets orbit the sun
Down
- 1. the motion of a body, such as a planet or moon, along a path around some point in space
- 4. – a thin, gray layer on the surface of the moon, consisting of loosely compacted, fragmented material believed to have been formed by repeated impacts of meteorites
- 5. the depression at the summit of a volcano or a depression produced by a meteorite impact
- 6. the time it takes for Earth to make one complete rotation (360º) with respect to a star other than the sun
- 7. designed and built instruments to measure the locations of the heavenly bodies
- 8. the moon passes through Earth’s shadow
- 10. a result of the motion of the moon and the sunlight that is reflected from its surface
- 11. created a model of the universe that accounted for the movement of the planets
- 12. the average distance between Earth and the sun
- 13. a long channel associated with lunar maria
- 14. He proposed a model of the solar system with the sun at the center
- 20. the point at which the moon is closest to Earth
- 21. an oval-shaped path
- 22. any of a system of bright, elongated streaks, sometimes associated with a crater on the moon
- 23. discovered three laws of planetary motion
- 27. the apparent westward motion of the planets with respect to the stars
- 28. a tide just after a new or full moon, when there is the greatest difference between high and low water
- 32. the time in July when Earth is farthest from the sun
- 33. the science that studies the universe
- 34. relation to stars or constellations
- 35. the turning, or spinning, of a body on its axis