Why Was It Difficult for Astronomers to Develop a Clear

Q40: At the center of our galaxy, _.<br>A)

Q41: " Spurs" are probably the result of

Q42: Stars at different distances from the galactic

Q43: Globular clusters are used as spiral tracers.

Q44: Almost all of the gas and dust

Q46: One of the most important features that

Q47: A group of one hundred to a

Q48: Elements above hydrogen and helium come from

Q49: Explain the reasoning that leads astronomers to

Q50: The mass of the Milky Way galaxy