Video Transcript
The image below shows a top-down
view of the Milky Way. What term is given to the features
marked in green? (A) Spiral arms, (B) spiral wings,
(C) rings, (D) circles, or (E) bars.
To begin, let’s take a closer look
at the image given to us. The image shows a depiction of the
Milky Way, which is the galaxy that our solar system is part of. Now, let’s recall that a galaxy is
a collection of billions of stars, and that’s what all these bright spots in the
image are. There are a few different types of
galaxies, and one useful way to classify them is by shape. Recall that the Milky Way is known
as a spiral galaxy.
Now, we’ve been asked about the
features of the galaxy that are marked in green. Notice that they have a spiral
shape to them. That’s a clue as to what the
correct answer is. These features are the reason we
say that the Milky Way is a spiral galaxy. Also, notice that the green lines
in the image aren’t closed shapes. They’re disconnected and sort of
interlocked with each other. They aren’t quite rings or circles,
so we can eliminate options (C) and (D). Option (E) isn’t quite right
either. While there are certain features of
galaxies that are referred to as bars, those features are straight. And that’s not what’s shown in
green here. Thus, we should eliminate option
(E) as well.
Now all that’s left to do is recall
that the features marked in green here are known as spiral arms, not spiral
wings. A fun fact about this is that the
different spiral arms of the Milky Way have different names, and the solar system is
part of the Orion Arm. Thus, we’ve seen that the features
marked in green in the image are known as spiral arms, so answer choice (A) is
correct.
