The Hubble Law is a relation between a galaxy's

The Hubble Law is a relation between a galaxy's
 
  a. mass and its luminosity.
  b. distance and its luminosity.
  c. mass and its recession velocity.
  d. distance and its recession velocity.
  e. mass and its diameter.

Question 2

Compared to the Earth, the moon is no longer geologically active because
 
  a. it is rotating too slowly.
  b. its radioactive elements were never abundant.
  c. it is much smaller in mass.
  d. its crust is too thin.
  e. it does not have water on its surface.

Question 3

A mega-parsec is equivalent to
 
  a. 3.26 light-years.
  b. 206,265 AU
  c. the age of our solar system
  d. a million parsecs.
  e. the diameter of the Milky Way galaxy.

Question 4

The presence of vesicular basalts among the lunar rock samples shows that
 
  a. the lunar surface was fragmented by meteorite impacts.
  b. volcanism did not occur on the moon.
  c. the crust must have been made of anorthosite.
  d. molten lava once flowed over the lunar surface.
  e. the moon was once hit by a very large meteorite.

Question 5

____ have elongated nuclei with spiral structure extending from the ends of the elongations. The Milky Way is a member of this class of galaxy.
 
  a. Spiral galaxies
  b. Barred spiral galaxies
  c. Elliptical galaxies
  d. Irregular galaxies
  e. S0 galaxies

Question 6

The lunar maria are
 
  a. the lava plains of the lunar lowlands.
  b. the smooth plateaus of the lunar highlands.
  c. less than one billion years old.
  d. moving plates of lunar crust.
  e. older than the lunar highlands.