Thousands of years ago, a mirage may have encouraged European explorers to sail across
the Atlantic Ocean in search of a new continent. This vision is a phenomenon seen off
far northern European coasts. This arctic mirage is also known by its Icelandic name,
the hillingar effect, and is a superior mirage that raises an image vertically
and may have a very lifelike look.
An arctic mirage is caused when a very cold surface is covered by a mass of air whose
temperature steadily increases with altitude. This causes light from an object to be
bent in a curve, whose arc matches that of the earth. In this way, the image is able to
travel hundreds of miles and enable the observer to see what is over the edge of the
horizon. This was the case when, in 1939, a ship’s captain claimed he saw Iceland’s
Snaefelljökull volcano from 300 miles away.
Researchers who have studied this effect have found evidence in Celtic and Norse legends
that North Atlantic peoples may have learned from experience that arctic mirages contain
dependable information about that which lies in the distance. Celts from the Faeroe
Islands above Scotland set out around 800 AD in small coracles, traveling 200 miles to
Iceland, supposedly guided by a mirage. A similar occurrence may have helped Icelandic
settlers following Erik the Red journey westward to Greenland in 980. Other explorers
may also have used such visions to find North America.