Across
- 3. The line of 0° longitude passing through Greenwich, England
- 7. Light from an object moving away from Earth
- 11. The slightly flattened shape of Earth
- 13. A device that proves Earth's rotation
- 14. A tool that breaks light into a spectrum of colors
- 15. A rocky planet, like Earth or Mars
- 20. The curving of winds and ocean currents due to Earth's rotation
- 24. Events caused by shadows cast by the Earth
- 26. The rate of change in a field value
- 31. Any object that orbits a planet, natural or man-made
- 32. The Sun and all objects that orbit it
- 34. The point directly above an observer’s head
- 38. A large group of stars, dust, and gas held together by gravity
- 41. Lines that measure distance north or south of the Equator
- 42. The distance light travels in one year
- 43. The line where the sky meets the ground
- 46. The time of day when the Sun is highest in the sky
- 48. The southernmost point on Earth
- 49. Icy objects that produce a glowing tail as they orbit the Sun
- 50. The day when daylight and nighttime are equal
- 52. The perceived movement of objects in the sky
- 53. A measure of how stretched an orbit is
- 55. Sunlight that hits Earth at a 90-degree angle
- 57. The layer of the atmosphere above the troposphere
- 61. Natural objects in the sky, like stars, planets, and moons
- 62. The boundary between the troposphere and stratosphere
- 64. The boundary between the stratosphere and mesosphere
- 65. The speed of an object
- 66. A massive ball of gas undergoing nuclear fusion
- 67. The lowest layer of Earth’s atmosphere
- 69. A Sun-centered model of the solar system
- 70. An Earth-centered model of the solar system
- 71. Earth’s natural satellite
Down
- 1. The theory that explains the origin of the universe
- 2. Closest point in a planet’s orbit around the Sun
- 4. The northernmost point on Earth
- 5. The atmospheric layer where meteors burn up
- 6. Lines that measure distance east or west of the Prime Meridian
- 8. The boundary between the mesosphere and thermosphere
- 9. A line connecting points of equal temperature
- 10. The average level of the ocean’s surface
- 12. Earth’s solid outer layer
- 16. The outermost atmospheric layer with very high temperatures
- 17. Fixed points that determine the shape of an ellipse
- 18. A region where the same standard time is used
- 19. A recognizable group of stars forming a pattern
- 21. The changing appearance of the Moon as it orbits Earth
- 22. The path a planet takes around the Sun
- 23. A space rock that hits Earth’s surface
- 25. The layer of gases surrounding Earth
- 27. The galaxy that contains our solar system
- 28. The day with the most daylight in the Northern Hemisphere
- 29. A line connecting points of equal air pressure
- 30. A line connecting points of equal value
- 33. A tool used to measure the altitude of stars
- 35. All of Earth’s water
- 36. All of space, time, and matter
- 37. An imaginary line halfway between the North and South Poles
- 39. The line that separates one calendar day from the next
- 40. The latitude where the Sun is directly overhead on December 21
- 44. A star located above Earth’s North Pole
- 45. A gas giant, like Jupiter or Saturn
- 47. The day with the least daylight in the Northern Hemisphere
- 51. Tides caused by the alignment of the Sun and Moon
- 52. A region of space between Mars and Jupiter with many small rocky objects
- 54. The latitude where the Sun is directly overhead on June 21
- 56. A force of attraction between objects
- 58. Caused by Earth’s tilt and revolution around the Sun
- 59. Earth’s yearly orbit around the Sun
- 60. The spinning of Earth on its axis, causing day and night
- 63. The height of a celestial object above the horizon
- 68. The process that powers stars by combining hydrogen into helium