20. Which statement about the Sun?s rotation is TRUE?

32. Radioactive dating techniques have revealed that our Earth and Moon are approximately how old?

32. Planets in the habitable zone of their stars:

32. Which of the following stages will our own Sun go through in the future:

15. Today, we believe that only a small number of elements were actually formed during the Big Bang. Which of the following was NOT one of these:

35. Astronomers estimate that there may be a trillion (a thousand billion) comet nuclei orbiting beyond Pluto. Why then do we not see more comets in our skies?

9. Which color star is likely to be the hottest?

3. When astronomers discuss a nebula, what are they talking about?

10. Which law do astronomers use to determine the masses of the stars in a spectroscopic binary system?

5. Astronomers today know a lot about the size and shape of the Milky Way Galaxy. Which of the following common objects most resembles the shape of our Galaxy?