Suppose a comet orbits the Sun on a highly eccentric orbit with ...

[NClaborn]

Suppose a comet orbits the Sun on a highly eccentric orbit with an average (semimajor axis) distance of 1 AU. How long does it take to complete each orbit, and how do we know?
 
  A) Each orbit takes about 1 year, which we know from Kepler's third law.
  B) It depends on the eccentricity of the orbit, as described by Kepler's first law.
  C) It depends on the eccentricity of the orbit, as described by Kepler's second law.
  D) Each orbit should take about 2 years, because the eccentricity is so large.

Question 2

The element first found in the Sun's spectrum, then on Earth 30 years later, is
 
  A) technicum. B) aluminum. C) solarium. D) hydrogen. E) helium.

[JYan]

Answer to Question 1

A

Answer to Question 2

E