In a diagram depicting the solar system as heliocentric, what is located at the center?
The orbit of a planet around the sun is a(an)
Which of the following helps explain why the planets remain in motion around the sun?
Which of the following objects does NOT orbit directly around the sun?
The moon most likely formed
Ocean tides are the result of
Study Figure 25-1. Suppose you are an astronaut on the side of the moon facing Earth during a total lunar eclipse. Which would you see as you look toward Earth?
What will happen to the relative amounts of hydrogen and helium in the sun over the next few billion years?
The distance between stars is typically measured in
The parallax of a star is observed because
Astronomers classify stars according to their
The apparent brightness of a star
The big bang theory explains the
Which of the following provides support for the big bang theory?
The gravitational force between two objects increases as mass