Astronomy Unit Review

Front

What evidence supports the Big Bang Theory?

Back

1. Galaxies moving away suggest universe expansion. 2. Abundance of hydrogen and helium. 3. Remnants of initial heat found by astronomers.

Front

What are common misconceptions about the Big Bang?

Back

1. It was an expansion, not an explosion. 2. Space did not exist prior to the Big Bang.

Front

What does the Big Bang Theory postulate about the universe's size 12 to 14 billion years ago?

Back

The universe was only a few millimeters across.

Front

What are the paths called that planets revolve around the Sun?

Back

Orbits, which are nearly circular.

Front

What is an orbital period?

Back

The time for one revolution around the Sun.

Front

What are the four inner planets?

Back

1. Mercury 2. Venus 3. Earth 4. Mars

Front

Why is Mars called the 'Red Planet'?

Back

Because of its rusty colored soil.

Front

What are the four outer planets?

Back

1. Jupiter 2. Saturn 3. Uranus 4. Neptune

Front

Why is Pluto considered a dwarf planet?

Back

It no longer meets the criteria to be considered a planet.

Front

What are the criteria for a celestial body to be considered a planet?

Back

1. Must orbit a star. 2. Must be spherical due to gravity. 3. Must have cleared its orbit of similar-sized objects.