Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
The carbon in my diamond ring was once part of interstellar dust grains.

. What are the Large and Small Magellanic Clouds, and the Sagittarius and Canis Major Dwarfs?

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
Planets like Earth probably didn’t form around the very first stars because there were so few heavy elements back then.

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
We did not understand the true size and shape of our galaxy until NASA launched satellites into the galactic halo, enabling us to see what the Milky Way looks like from the outside.

What is Sgr A*? What evidence suggests that it contains a massive black hole?

What evidence suggests that the Milky Way formed from the merger of smaller protogalactic clouds?

Briefly describe the characteristics that distinguish disk stars from halo stars.

What triggers star formation within a spiral arm? How do we think spiral arms are maintained?

How do we know that spiral arms do not rotate like giant pinwheels? What makes spiral arms bright?

What are ionization nebulae, and why are they found near hot, massive stars?

Briefly summarize the different types of gas present in the disk of the galaxy, and describe how they appear when we view the galaxy in different wavelengths of light.

What do we mean by atomic hydrogen gas? How common is it, and how do we map its distribution in the galaxy?

Draw simple sketches of our galaxy as it would appear faceon and edge-on. Identify the disk, bulge, halo, and spiral arms, and indicate the galaxy’s approximate dimensions.

Use the following questions to check your understanding of what the images show and what we can learn by comparing them.
The image of radio emission uses different colors to represent different levels of intensity. Which color represents the brightest radio emission? Which color represents the lowest levels of brightness?