According to Kepler's third law, the square of the planet's period in years is :

According to Kepler's third law, the square of the planet's period in years is
 
  A) equal to its perihelion distance from the Sun in AU.
  B) inversely proportional to its mass in kilograms.
  C) equal to the fourth power of its average temperature in degrees Kelvin.
  D) proportional to the cube of its semimajor axis in AU.
  E) equal to the square of its aphelion distance in AU.

Question 2

When it was determined that Sedna has a perihelion distance that is three times further out than Pluto and such an eccentric orbit that it has a period of thousands of years, it was placed in the:
 
  A) Trojan Asteroids.
  B) Kuiper Belt.
  C) Kirkwood Gap.
  D) Oort Cloud.
  E) Rogue Comets.

Question 3

The Orion Nebula and Tarantula Nebula are examples of ________ Nurseries.
 
  Fill in the blank(s) with correct word