A) Mars
B) Jupiter
C) Neptune
D) Saturn

A) A signal from outer space
B) A type of space telescope
C) A substance that provides scientific evidence of past or present life
D) An alien language

A) The habitable zone around a star where conditions are just right for life
B) The area where space missions look for extraterrestrial life
C) A region of space filled with gold
D) A zone controlled by an alien species

A) Estimating the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy
B) Calculating spaceship speeds
C) Predicting comets' trajectories
D) Determining ocean temperatures on exoplanets

A) A rotating neutron star that emits beams of electromagnetic radiation
B) A celestial event marking the birth of a star
C) An alien spacecraft
D) A type of planet with extreme weather

A) The first message from aliens
B) A strong narrowband radio signal detected by astronomer Jerry R. Ehman in 1977
C) A code used by space agencies
D) A theory about the origin of the universe

A) A list of potential candidates for space colonization
B) A guide to space exploration equipment
C) A database of known exoplanets that are considered potentially habitable
D) A directory of alien species

A) Because they are immune to cosmic radiation
B) Because extremophiles show that life can exist in extreme environments
C) Because they are alien species
D) Because they provide energy to spacecraft

A) A method of communication with aliens
B) A new type of telescope for deep space exploration
C) A type of exoplanet
D) A hypothetical megastructure that completely surrounds a star and captures its energy