Equator
Imaginary line that runs around the middle or widest part of the earth.
It is the hottest part of the planet.
0 degress latitude
Divides the earth between the Northern Hemisphere and Southern Hemisphere.
http://www.youtube.com/watch?v=cKT16DjHo_8
http://encyclopedia.kids.net.au/page/eq/Equator
http://www.socialstudiesforkids.com/articles/geography/equatorprimemeridian.htm