Compare the way an optical and radio astronomer would map the Galaxy. What will be an ideal ...

Compare the way an optical and radio astronomer would map the Galaxy.
 
  What will be an ideal response?

Question 2

Which planet had the Great Dark Spot in 1989, but had lost it by 1995?
 
  A) Jupiter B) Saturn C) Mars D) Neptune E) Uranus

Question 3

The average temperature of the typical dark dust cloud is about
 
  A) 0 K. B) 2.73 K. C) 100 K. D) 3,000 K. E) 6,000 K.

Question 4

Why does Saturn radiate even more excess heat than Jupiter?
 
  A) Helium rain falling inward generates heat as it descends.
  B) Saturn's atmosphere contains much methane, which is very flammable.
  C) Only Saturn is still radiating heat left over from its formation.
  D) Saturn's thick clouds give it a stronger greenhouse effect.
  E) Saturn is more massive than Jupiter, so its gravitational compression is stronger.