What is the theoretical upper limit to the mass of a neutron star, beyond which it will collapse into a black hole?

What process creates elements heavier than iron?

What is the name of the hypothetical boundary beyond which no light or radiation can escape a black hole?

What is the primary component of the interstellar medium (ISM)?

Which of these is NOT a type of galaxy?

What is the approximate age of the universe, according to the Big Bang theory?

What is the name given to the faint afterglow of the Big Bang?

What does the Drake Equation attempt to estimate?

Which mission first successfully landed humans on the moon?

What is the closest star system to our solar system?