Scale of the Universe Review

Front

What is a galaxy?

Back

A galaxy is a collection of billions of stars and the planets and smaller objects that go around them.

Front

What unit of measurement is best for measuring the distance between the Sun and Proxima Centauri?

Back

Light Year.

Front

Which planet has a year (Period of Revolution) that is shorter than its day (Period of Rotation)?

Back

Venus.

Front

What is a planet?

Back

A large body made of gas or rock that orbits a star.

Front

Why don't we use light years to measure distances within our solar system?

Back

The light year is too big.

Front

What is the closest star to Earth?

Back

Proxima Centauri.

Front

What is the Milky Way?

Back

The Milky Way is the galaxy that contains our Solar System.

Front

What is an astronomical unit (AU)?

Back

An astronomical unit is the average distance from the Earth to the Sun, about 93 million miles.

Front

What is the difference between a planet and a star?

Back

A planet orbits a star and does not produce its own light, while a star generates light and heat through nuclear fusion.

Front

What is the Period of Rotation?

Back

The Period of Rotation is the time it takes for a planet to complete one full spin on its axis.