Video Transcript
Which of the following statements
correctly describes what stars are? (A) Stars are very large, very hot
objects that are far away from the solar system. (B) Stars are small, hot objects at
the edge of the solar system. Or (C) stars are small, hot objects
located just above the atmosphere.
In this question, we need to
describe what stars are. Notice that here each option
describes the size of stars. Option (A) says that they’re very
large, but options (B) and (C) say that they’re very small. Let’s think about this
distinction.
If we go outside on a clear night,
we can likely see stars in the sky. They may appear to be tiny little
objects just beyond the clouds, which is how they’re described in option (C). However, this is not an accurate
description. Stars appear small when we see them
in the sky. But in fact, this is only because
they’re so far away. Some of the stars that we see are
thousands of light-years away. That’s thousands of trillions of
kilometers.
Consider the fact that the Sun is a
star. The Sun appears to be significantly
larger than the stars we see at night, because the Sun is significantly closer to us
than other stars are. If the Sun doesn’t appear to be
that large, it’s because it’s still hundreds of millions of kilometers away, even
though it’s the closest star to Earth. In reality, our Sun, which is an
average-sized star, is millions of times larger than the Earth. And some stars are thousands of
times bigger than the Sun. So, since most stars are at least
millions of times bigger than Earth, we know that stars are not small. So we can eliminate options (B) and
(C).
This leaves us with option (A),
which says that stars are very large, very hot objects that are far away from the
solar system. Well, we’ve seen that stars are
very large, millions of times bigger than Earth. And it’s true that stars are very
hot, too. At its core, the Sun is about 15
million degrees centigrade. We’ve also seen that stars are very
far away. Of course, there is one star that’s
actually in the solar system, the Sun. But all of the other billions and
billions of stars in the universe are much farther away.
Stars are very large, very hot, and
very far away. So, we know that option (A) is the
correct answer.
