The Universe

Which of the following best describes the relationship between the Solar System and the Universe?

• The Solar System is the largest known galaxy in the Universe.

• The Solar System is in one of the billions of galaxies in the Universe.

• The Solar System contains most of the galaxies in the Universe.

• The Solar System and the Universe are both part of the same galaxy.

Which belief is the basis of Ptolemy's geocentric model of the solar system?

• The Sun and planets revolve around the Earth.

• Jupiter is the same size as the Earth's moon.

• The Sun is the center of the universe.

• The Earth revolves around the Moon.

The Milky Way Galaxy contains

• billions of stars and the objects in orbit around them.

• billions of stars but not the objects in orbit around them.

• all of the stars throughout the Universe.

• only the objects found in the Solar System.

Which of the following theories describes the formation of the Universe as a gigantic explosion from a single point that threw out all of the material in the Universe in all directions?

• theory of evolution

• big bang theory

• heliocentric theory

• geocentric theory

Which of the following theories explains why the Universe is expanding at a great speed?

• theory of evolution

• geocentric theory

• heliocentric theory

• big bang theory

In past centuries, many people believed in a static Universe—one that had existed forever without changing much, and one that would continue forever more or less as it is today.

Which of the following facts supports the big bang theory and disproves the static model of the Universe?

• Stars are held together by gravity within galaxies.

• Stars are constantly forming and dying.

• Light moves at a constant speed through empty space.

• Most galaxies appear to be moving away from each other.

Copernicus was the first astronomer to develop a heliocentric model of the Solar System. What is the main idea of heliocentrism?

• An asteroid is the center of the Universe.

• The planets move toward the center of the Universe.

• The Sun is the center of the Solar System.

• The Earth is the center of the Universe.

Which type of force holds galaxies together?

• electrostatic forces

• magnetic forces

• friction

• gravity

The Earth, the Sun, and the seven other planets that are in orbit around the Sun are part of the Solar System. How does the size of the Solar System compare with the size of the Milky Way Galaxy?

• The Solar System is the same size as the Milky Way Galaxy.

• The Solar System is around half the size of the Milky Way Galaxy.

• The Solar System is much smaller than the Milky Way Galaxy.

• The Solar System is much larger than the Milky Way Galaxy.

Other galaxies observed by astronomers are almost all redshifted. This means that most galaxies are moving away from our galaxy. Since this is true in every direction, the galaxies are all moving away from each other.

Imagine that the universe is a solid ball with galaxies scattered all through it from the center to the edge. Suppose the galaxies stay the same size, but the ball gets bigger. What will happen to the distance between the galaxies?

• The distances between the galaxies will change randomly depending on the galaxies' motion.

• The distances between all the galaxies will increase throughout the ball.

• The distances between the galaxies near the center of the ball will decrease.

• The distances between only the galaxies on the surface of the ball will increase.