Name: 

Galaxies are clusters of ____ of stars.

The name of the galaxy to which the Sun and our solar system belong is:

When you look up at the night sky from Earth, the Milky Way looks most like:

American astronomer, ____, was the first to discover a galaxy outside our own. In 1990, a famous telescope named after him was launched into orbit.

Galaxies are classified according to their shape. The Milky Way is classified as a:

The stars of the Milky Way are arranged in a spiral disk. The distance across the disk is:

Distance between galaxies is usually measured in:

The name of the current theory used to explain the beginning of the universe is:

According to the most recent theory of the origin of the universe, all of the matter and energy of the universe was compressed into a space no larger than:

The formation of the universe according to the most widely accepted scientific theory has taken:

In the early twentieth century, astronomers believed that the Milky Way galaxy was the entire universe. But as better telescopes were invented, astronomers realized that some “smudges” of light were not stars in the Milky Way galaxy, but whole other:

The location of the Sun in the Milky Way is:

The distances between galaxies are:

Astronomers use ____ to estimate the distance between galaxies.

Because the universe is constantly expanding, the color of stars is shifted toward:

The galaxy to which the Sun belongs is called the _________________________ galaxy.

The unit most commonly used to describe distances between galaxies is the _________________________.

American Astronomer, _________________________, was the first to discover a galaxy other than our own. A famous telescope launched into orbit in 1990 was named after him.

The theory that the universe started as a huge explosion 10 to 20 billion years ago is named the _________________________.

If you look up at the night sky from Earth (without using a telescope), what does the Milky Way galaxy look like?

Galaxies are classified according to their shape. List the four most common galaxy shapes.

What shape is the Milky Way galaxy? Do astronomers believe it will always remain this shape? If not, describe one possible way the Milky Way galaxy’s shape might change.

What is the most reliable method that astronomers use to estimate the distance to a galaxy?

Name two pieces of evidence to support the Big Bang theory for the origin of the universe.

Compare the distances between planets, the distances between stars, and the distances between galaxies. What unit is most useful for describing each of these distances?

Recent evidence suggests that there is a black hole at the very center of the Milky Way. Explain why scientists reached this conclusion.

The Milky Way is a relatively flat disk containing 200 billion stars. Draw a diagram of the Milky Way as it might appear from above this disk. In the drawing indicate the position of:
(1) our Sun
(2) a possible black hole