could clearly see the mountain tops of "Crocker Land" across
the polar ice pack, but it was only an Arctic Mirage.
Lee Krystek, 1998)
On June 23, 1744, a phantom army appeared floating
above a mountain in Scotland. Twenty seven people, who later
gave sworn testimony to what they'd seen, watched the strange
vision for two hours till it ended with darkness.
In the summer of 1897 in Alaska, an expedition
to the wilderness near Mount St. Elias saw a "Silent City" over
a glacier. A member of the expedition, C. W. Thornton, wrote,
"It required no effort of the imagination to liken it to a city,
but was so distinct that it required, instead, faith to believe
that it was not in reality a city." Another witness reported,
"We could plainly see houses, well-defined streets, and trees.
Here and there rose tall spires over huge buildings..."
The above incidents are examples of a startling
optical atmospheric effect known as a mirage. Though we associate
mirages with the illusion of distant water in a desert, the
phantom oasis is actually just the simplest example of this
A mirage is generated by two layers of air at
different temperatures. Because cold air is more dense than
hot air, the boundary between the layers can refract (bend)
light, especially if the light hits the boundary at an extreme
angle. The oasis mirage occurs when the air just above the ground
gets hot because the ground heats it.
effect can commonly be seen on asphalt roads during the summer.
The black color of the road gets the air above it hot very quickly.
At the boundary of the hot and normal air, light is refracted.
The viewer no longer sees the road or desert floor, but light
refracted from the blue sky which, because it is on the ground,
looks like water.
A mirage can also be the result of a temperature
boundary between layers of air in the sky. If the boundary is
not flat, but curved, the mirage will not only display a mirror
image, but act as a lens, and magnify distant images. Sir David
Brewster speculated that the phantom soldiers above the mountain
were caused by a mirage that reflected troops on maneuvers on
the other side of the mountain from the witnesses.
Mirages in the sky may also be the source of
many UFO reports. The planet Venus magnified and distorted by
a mirage makes a believable flying saucer. Since the properties
of the mirage change with the movement of the air masses, objects
in the mirage may twinkle, jump around, seem to speed away or
When the effect appears above the water, it is
often referred to as a Fata Morgana. The phrase comes
from the Italian version of the name of the sorceress Morgan
Le Fay from the legends of King Arthur and Camelot.
In ancient times these strange effects were considered the work
The schooner Effie M. Morrissey was sailing the
North Atlantic on July 17, 1939 when a Fata Morgana appeared.
Though the coast of Iceland was some 320 miles away, Captain
Bartlett indicated that it appeared as if it was only twenty
five miles away. "The contours of the land and the snow-covered
summit of the Snaefells Jokull showed up almost unbelievably
Morganas may also be the cause of legends about phantom ships
that sail the sky. Reports of the ghost ship Flying Dutchman
may well have been the reflection of some distant vessel.
Scientists believe Fata Morganas are most likely
to form when the sea is much colder than the atmosphere. As
the water cools the air directly above it, a boundary layer
forms. These types of mirages are most likely to show up after
dawn, before dusk or as a storm is building up. They also tend
to favor particular locations. The Straits of Messina, between
Sicily and the Italian mainland, are famous for its Fata Morganas.
When several boundaries of air are involved,
a mirage can become even more complex as the light is refracted
multiple times. This can make natural objects, like cliffs,
appear as city buildings, or castles. This is probably the best
explanation for the Alaskan City mirage, though some contend
that it was actually a magnification of the English city of
Bristol some 2,500 miles away.
The Arctic is famous for mirages and one such
image cost the American Museum of Natural History a small fortune.
The story started in June of 1906 when Robert
E. Peary, who would be the first man to reach the north
pole in 1909, was studying the horizon from the summit of Cape
Colgate, a point in the extreme northwestern part of North America.
Peary wrote that "North stretched the well-known ragged surface
of the polar pack and northwest it was with a thrill that my
glasses revealed the white summits of a distant land." Peary
estimated that this unknown land lay 120 miles offshore and
named it "Crocker Land" after one of his financial backers.
Seven years later the Museum of Natural History
committed $6,000, a significant sum at the time, to outfit an
expedition to explore "Crocker Land." On April 13th of that
year the group reached a spot near where Peary had spotted the
land and set out across the polar ice pack in the direction
indicated by Peary. The journey was difficult and dangerous,
but after about a week the expedition was treated to a glimpse
of this new land when the weather cleared. One of the members
wrote later, "we ran to the top of the highest mount. There
could be no doubt about it. Great heavens! What a land! Hills,
valleys, snow-capped peaks extending through at least one hundred
and twenty degrees of horizon."
The Eskimos traveling with the expedition were
unimpressed and said that the vision was poo-jok, which
translates to "mist." The group traveled one more day forward
and then took their position using a sextant and the sun. Shocked,
they realized they were 150 miles onto the polar ice cap. According
to Peary's calculations, they should have been 30 miles inland
at that point. The expedition realized that both they and
Peary had been fooled by a mirage. Disappointed, they started
back. Behind them, though, the mirage persisted, mocking them
as they returned. When they reached the point where Peary had
seen "Crocker Land" from the shore, they took a look themselves.
They reported, "There was land everywhere! Had we not just come
from far over the horizon we would have returned to our country
and reported land as Peary did."
Delays in retrieving the group stretched the length
of the expedition to five years and the cost to $100,000. While
the trip did result in the collection of much valuable information,
it was still considered a failure. All because of an Arctic
illustration at the left is a computer-generated simulation
of a mirage. A program capable of accurately rendering an image
was given the position of the ground, a partly-refractive boundary
layer in the sky and a ship model. Between the observer position
and the ship was also placed a mountain. The ship, though not
directly visible because of the mountain, can be seen as a slightly-distorted
mirage above the mountain peak. In nature the clarity of the
image, its size,whether it is upside down and if there is more
than one image would depend on a number of factors including
the smoothness, shape and number of boundaries.
reflection and refraction at a boundary layer.
Krystek 1996, 1998. All Rights Reserved.