Astronomy 2

geocentric

model of the solar system in which the Earth is in the center of the universe

heliocentric

model of the solar system with the Earth revolving around the Sun

Stonehenge

is the site of several henges, or ditches surrounded by banks, in England

Henges

ditches surrounded by banks

Mayan Civilization

flourished in present-day Mexico, Belize, Guatemala, El Salvador, and Honduras from about 2600 BCE, with its golden age spanning 300-900 CE

Aztec Civilization

thrived from between 1100 and 1521 CE, but descendants of the Aztecs still live and practice certain cultural traditions in Mexico

Century (Aztec)

a 52-year cycle in the Aztec calendar

Space Race

a competition between the US and USSR as to who could do what first in human space exploration

FAI

the international governing body overseeing aerospace records

re-entry

the moment when a space craft comes back into Earth’s atmosphere

Deep Space Network (DSN)

an international network of spacecraft communication services