The Earth turns to the east as it rotates. It spins 1 degree longitude every 4 minutes. On the equinox, locations at the same longitude experience sunrise at the same time.
Time and Longitude
Locate the Prime Meridian and Greenwich, England on the map.
- Longitude: How far east or west of the Prime Meridian do you live (in degrees)?
- Time: What is the time difference between Greenwich, England and your home town (in hours and minutes)?
Time Clues on March 11
These facts will help you use the time clues to estimate the longitude of the Mystery sites:
- The Prime Meridian is the reference line you will use for measuring longitude.
- Greenwich, England is the reference point you will use for measuring time.