41. What is a black hole?
a) A region of space with extremely high gravitational forces, from which nothing, not even light, can escape
b) A region of space with extremely low gravitational forces, in which objects can float freely
c) A type of star that emits large amounts of radiation
d) A type of planet that emits large amounts of radiation
42. What is the cosmic microwave background radiation?
a) A type of radiation emitted by black holes
b) A type of radiation emitted by pulsars
c) The afterglow of the Big Bang, in the form of microwave radiation that is still present throughout the universe
d) The radiation emitted by the sun
43. What is dark energy?
a) A mysterious force that is causing the expansion of the universe to accelerate
b) Matter that emits no light or other electromagnetic radiation, and can only be detected by its gravitational effects
c) Matter that is extremely dense and emits high levels of radiation
d) Matter that is composed of antimatter particles
44. What is the study of the universe and its contents known as?
a) Biology
b) Chemistry
c) Physics
d) Astronomy
45. What is the term used to describe a group of stars that form a recognizable pattern in the sky?
a) Galaxy
b) Constellation
c) Nebula
d) Asterism
