Solar System

3. the surface of this planet is over 100 degrees Celsius below the lowest natural temperature ever recorded on Earth.
4. there are at least 164 of these in our solar system. (hint: these are created by reflecting off the sun)
6. a year on this planet is 11.9 years on Earth.
8. the planet named after the Roman god of War.
11. the only planet in our solar system NOT named after a Greek or Roman god.
14. The ____________ _________ are the four largest moons of Jupiter.
16. the center of the solar system.
17. the smallest planet in the solar system.
18. Until recently, was considered the ninth planet in our solar system.

1. Not counting transient events such as gamma-ray bursts, the brightest object in the gamma-ray sky is the this.
2. the sixth planet from the sun.
5. the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter.
7. a celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such.
9. the _______ _____ is between Mars and Jupiter.
10. the only planet that lays on it's side.
12. the number of non-dwarf planets in the solar system.
13. referred to as "Earth's sister".
15. if a solar system has two or more stars it is actually called a __________ system.