Front

What is a scientific theory?

Back

A well tested explanation for why something happens.

Front

What is the relationship between the size and luminosity of a star?

Back

As size increases, luminosity increases.

Front

Which of the following is NOT evidence for the Big Bang Theory?

Back

The universe is shrinking.

Front

List the astronomical structures from smallest to largest.

Back

Planet, planetary system, galaxy, universe.

Front

What does the universe include?

Back

All the matter known to exist, all the space that exists, nearly 200 billion galaxies.

Front

What is the definition of a galaxy?

Back

A massive system of stars, stellar remnants, interstellar gas, dust, and dark matter, bound together by gravity.

Front

What is the Big Bang Theory?

Back

The leading explanation about how the universe began, stating it was born from a singularity and has been expanding ever since.

Front

What is cosmic microwave background radiation?

Back

The afterglow radiation from the Big Bang, filling the universe and providing evidence for the Big Bang Theory.

Front

What is redshift in astronomy?

Back

The phenomenon where light from an object is shifted to longer wavelengths, indicating that the object is moving away from the observer.

Front

What is a planetary system?

Back

A star and all the celestial bodies bound to it by gravity, including planets, moons, asteroids, and comets.