A system of stars, gas, dust, and dark matter bound together by gravity is called -
Which of the following best describes a star? A star is a celestial body -
Which of the following is an accurate description of the relationship between components of the universe?
The universe has many different components. Which list places four components of the universe in the most likely order from smallest to largest?
The Milky Way galaxy is described as a disk of stars orbiting a central point on the disk. Which of these best explains why people on Earth cannot see the entire shape of the Milky Way?
A student learns that the sun is classified as a medium-size star and that many stars are much bigger and brighter. However, the student observes that other stars look very dim, even through a telescope.
Why do other stars look much dimmer than the sun?
A student makes a model of the sun-Earth system by swinging a ball around her head. Using this model, the student is trying to explain how Earth stays on a path around the sun.
The student explains that this path is the result of -
An object will continue moving in a straight line unless it is acted on by an unbalanced force. Which of the following best explains Earth's motion?