Earth and Space

3. a year, occurring once every four years, that has 366 days including February 29 as a day.
4. the path an object follows as it moves around another one.
5. a dark area or shape produced by a body coming between rays of light and a surface.
8. The motion of an object around a point, especially around another object or a center of mass
9. once in about 24 hours with respect to the Sun.
11. the action or process of moving or being moved.
12. the collection of eight planets and their moons in orbit around the sun.
13. the force that attracts a body toward the center of the earth, or toward any other physical body having mass.
17. Balanced forces are those that are equal in magnitude but opposite in direction.
18. a fixed luminous point in the night sky which is a large, remote body like the sun.
19. any theory of the structure of the solar system (or the universe) in which Earth is assumed to be at the centre of it all.

1. a group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure
2. one half of a sphere.
6. an astronomical theory in which the Earth and planets revolve around the Sun at the center of the universe.
7. a measure of a material's resistance to permanent deformation or complete breakage under stress.
10. a real or imaginary straight line going through the center of an object that is spinning, or a line that divides a symmetrical shape into two equal halves
14. a range of longitudes where a common standard time is used.
15. strength or energy as an attribute of physical action or movement.
16. the force applied in one direction is greater than the force applied in the opposite direction.