S6E1a & S6E1b -Flashcard Review

Front

What is the Big Bang?

Back

The theory of the universe that states that all matter and energy was once packed in a tiny, dense singularity that then exploded about 14 billion years ago. The universe then began expanding and cooling, and is still doing so today.

Front

What is the Heliocentric model?

Back

A Sun-centered universe where the planets revolve around the sun.

Front

What is the Geocentric model?

Back

An Earth-centered universe where all celestial bodies revolve around the Earth.

Front

What did Ptolemy believe about the universe?

Back

He thought Earth was in the center of the universe.

Front

What shape does the galaxy that includes the Sun resemble?

Back

The Milky Way galaxy, which is spiral in shape.

Front

What is a galaxy?

Back

A large system of stars, gas, dust, and dark matter bound together by gravity.

Front

What is the Milky Way?

Back

The galaxy that contains our solar system, shaped like a spiral.

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 an orbit?

Back

The path one object takes around another object in space due to gravitational forces.

Front

What is gravity?

Back

A force that attracts two bodies towards each other, keeping planets in orbit around stars.