A cloud fragment too small to form a star becomes:

A cloud fragment too small to form a star becomes:
 
  A) a red giant.
  B) a black hole.
  C) a brown dwarf.
  D) a T Tauri object.
  E) a Herbig Haro object.

Question 2

Most of the mass of the Milky Way seems to exist in the form of:
 
  A) Population I stars in the disk.
  B) Population II stars in the Halo.
  C) hydrogen gas in the disk and spiral arms.
  D) dark matter out in the Halo.
  E) the black hole in the Galactic Center.

Question 3

The universe was ________ old when electrons and positrons formed.
 
  Fill in the blank(s) with correct word

Question 4

For hydrogen, the transition from the second to the fourth energy level produces:
 
  A) a red emission line.
  B) a blue green absorption line.
  C) a violet emission line.
  D) an infrared emission line.
  E) an ultraviolet absorption line.

Question 5

How does the axial tilt of Mars compare with our own?
 
  A) Like Jupiter, Mars always keeps its equator pointing at the Sun.
  B) It is about half our own, 12 degrees.
  C) It is almost identical to the Earth.
  D) Like Saturn, it's about 27 degrees.
  E) Like Uranus, it is 98 degrees and flopped over on its side.

Question 6

Before it arrived in orbit about Eros, the NEAR spacecraft also flew past:
 
  A) Venus.
  B) asteroid Mathilde.
  C) Comet Wild.
  D) Mars.
  E) Comet Halley.