The Aztecs developed an intricate stone calendar to let them know when
to plant and harvest crops, as well as pray to the gods for the success
of the crops. This replica of an Aztec calendar is on exhibit In Bringing
the Heavens to Earth, currently at Adler Planetarium and Astronomy Museum.
© 2002 Adler Planetarium
and Astronomy Museum, Chicago, IL. Photo by Steven Lane. Reproduced with
permission of the copyright owner. Further reproduction or distribution
is prohibited without permission.