Across
- 3. The angle between the Sun's rays and the vertical direction (the zenith).
- 6. Ptolomy's astronomical model where the Earth is considered the static center of the universe, with the Sun, Moon, planets, and stars revolving around it
- 7. Copernicus's astronomical model that places the Sun at the center of the solar system, with Earth and other planets orbiting it
- 11. the orbital plane of a planet around a star
- 12. the angular distance of a place north or south of the earth's equator, usually expressed in degrees and minutes N or S
- 13. the spinning motion of a celestial object around an imaginary line called an axis
- 14. the moments in Earth's orbit when day and night are exactly the same length because the earth is not pointing toward or away from the sun.
- 16. the angular distance of a place east or west of the meridian at Greenwich, England, usually expressed in degrees and minutes E or W
- 17. the circle of latitude that divides Earth into the Northern and Southern hemispheres.
Down
- 1. the moment in Earth's orbit when the Sun appears farthest north or south of the celestial equator resulting in the longest and shortest days of the year
- 2. the 0-degree line of longitude that divides the Earth into the Eastern and Western Hemispheres
- 4. the point in the orbit of a planet, asteroid, or comet where it is closest to the sun
- 5. The angle between the Sun's rays and the horizontal plane.
- 8. the curved path that a celestial object, like a planet, moon, or spacecraft, takes around another, larger object, such as a star or planet
- 9. the point in the orbit of a planet, asteroid, or comet where it is farthest from the Sun
- 10. the complete, 360-degree orbit of one celestial body around another
- 15. the amount of solar radiation reaching a given area.