Astronomers

2. Created the three laws of planetary motion
5. Stated that the annual movement of the sun in the sky can be explained by the earth moving around the sun with a tilted axis.
7. Created a model that required the planets not only to move in circles around the earth, but also along smaller cycles called epicycles around imaginary points.
9. Created a model of a geocentric solar system where the Earth is the center and the rest of the planets and the sun revolve around it.
10. Noticed the path of a comet which required it to traverse the orbits of several planets, known as the Comet of 1577
12. A sun centered solar system
13. Discovered 4 moons around Jupiter, now known as the 4 Galilean moons (Titan, Io, Ganymede, Callisto)

1. A measure of how circular an orbit is
3. The natural satellite of the Earth
4. A earth centered solar system
6. The new moon mission that plans to send people back to the moon in 2025
8. A celestial body that orbits around a star
11. An elliptical, repeating path that an object in space takes around another one