Quiz tests knowledge of Apollo astronauts who walked on the moon

Twelve American astronauts have walked on the moon during the Apollo missions. They are the only people to have left bootprints on the lunar surface. A quiz challenges participants to name all 12 astronauts within six minutes. Hints are available for those who need assistance. The quiz is part of a series that includes other space-related topics, such as constellations and black holes. Participants can log in to track their scores on a leaderboard.