The Average Temperature of the Typical Dark Dust Cloud Is

Q1: Interstellar absorption lines are narrow primarily because:<br>A)there

Q2: Interstellar gas is composed of:<br>A)only hydrogen.<br>B)90% hydrogen,

Q3: The overall dimming of starlight by interstellar

Q5: Why is 21-cm radiation so important to

Q6: Explain the colors of emission nebulae.

Q7: Why are dark dust clouds largely misnamed?<br>A)The

Q8: Emission nebulae like M42 occur only near

Q9: If dark nebulae are really dark, how

Q10: What does the polarization of starlight tell

Q11: The gas in the interstellar medium consists