These objects are no longer considered a good explanation for the dark matter in the halo.
A) WIMPs
B) MACHOs
C) black holes
D) clouds of cool, neutral hydrogen
E) brown dwarfs
Question 2
Mars is best viewed from Earth when it is at:
A) perihelion.
B) opposition.
C) conjunction.
D) aphelion.
E) None of the above.