It’s one of the most miraculous journeys in the natural world:
sea turtles travel thousands of miles across the ocean to return
to the very beach where they first scuttled into the sea. There
aren’t exactly brightly lit mile markers in the sea, so how they
do it? Scientists from the University of North Carolina (my alma
mater!) say they have figured it out. The researchers say that
loggerhead sea turtles appear to be able to determine their
longitude using the strength and angle of the Earth's magnetic
field. Although several species of turtles are known to use
magnetic cues to determine latitude, it had never been shown for
longitude. I didn’t realize this, but apparently the most
difficult part of open-sea navigation is determining longitude
(east-west position.) While human navigators struggled for
centuries to figure it out on long-distance voyages, loggerhead
hatchlings are naturals as soon as they hit the water. To carry
out the research loggerhead hatchlings were placed in circular
water containers and