Earth

2. – A direction corresponding to the top of the Earth.
4. – To make something a part of a whole.
5. – A cardinal direction opposite to north.
7. – A cardinal direction, opposite to west.
8. – A perfectly round three-dimensional object, like a ball.
9. – A point on the Earth's surface where the axis of rotation meets, located at the farthest north or south.
11. – Imaginary lines running from the North to the South Pole, used to measure longitude.
12. – The measurement of distance north or south of the equator.
15. – When the sun appears to drop below the horizon.
16. – The imaginary line that divides the Earth into the Northern and Southern Hemispheres.
18. – A division of the year marked by changes in weather, daylight, and temperature.

1. – Having the shape of a sphere or ball.
3. – The measurement of distance east or west of the prime meridian.
6. – Half of the Earth, divided by either the equator or a meridian.
9. – Imaginary lines running around the Earth, parallel to the equator, used to measure latitude.
10. – The average weather conditions of a region over a long period of time.
13. – A fraction representing 66.67% of a whole.
14. – When the sun appears to come up over the horizon.
17. – A cardinal direction, opposite to east.