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December 1997


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Steve Cavrak <[log in to unmask]>
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Technology in Education <[log in to unmask]>
Wed, 10 Dec 1997 16:17:52 -0500
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University News Services
University of Iowa

100 Old Public Library
Iowa City IA 52242
(319) 384-0009; fax (319) 384-0024
e-mail: [log in to unmask]

Immediate Release: 12/9/97

UI's Louis Frank presents additional proof for "small comet" theory

IOWA CITY, Iowa -- Two University of Iowa space physics
researchers today, Tuesday, Dec. 9, presented a new study based
upon photographs taken by cameras aboard NASA's Polar spacecraft
as further proof of their 11-year-old theory that thousands of
house-sized ice comets disintegrate in the Earth's atmosphere each

Louis A. Frank and John B. Sigwarth presented the study at the
fall meeting of the American Geophysical Union (AGU) in San
Francisco. The study shows dark spots (called "atmospheric holes"
because of their appearance on film) captured in NASA photographs
decrease in size and number as the Polar spacecraft's altitude and
distance from the holes increases -- just what one would expect to
find if the cameras are taking pictures of a real phenomenon.
According to Frank, skeptics of the small comet theory who have
maintained that the atmospheric holes are caused by electronic
"noise" affecting the camera will now have to re-evaluate their

"This result is a marvelous confirmation of the reality of
atmospheric holes," says Frank, a Fellow of the AGU and of the
American Physical Society.

The latest study examines June 1, 1997 photographs of the Earth's
upper atmosphere, comparing one set of pictures taken from between
3 and 5 Earth radii above the surface to another set taken at
altitudes of between 5 and 8 Earth radii. A total of 5,650
atmospheric holes were observed in the images, however the high
altitude photographs showed an 80 percent drop in the frequency of
atmospheric holes in comparison to the low altitude data. Also a
greater number of atmospheric holes were photographed during early
morning hours than during evening hours.

At the spring AGU meeting in May, Frank revealed a series of
photographs taken by cameras aboard NASA's Polar spacecraft as
proof of the existence of the 20-to-40-ton ice comets that, over
the age of the Earth, could have provided enough water to fill the
oceans and plant the seeds of life. The pictures ranged from one
of a small comet the size of a two-bedroom house disintegrating
some 5,000 to 15,000 miles above the Atlantic Ocean to an image of
light emitted by the breakup of water molecules from a small comet
less than 2,000 miles above the Earth. Frank and Sigwarth, who
co-discovered the small comets and designed the three Visible
Imaging System (VIS) cameras aboard the Polar spacecraft, said
the pictures proved the existence of the small ice comets, but
some doubters remained. (Since then, a satellite trailing the
Space Shuttle Discovery in August detected significant amounts of
high-altitude water vapor, a finding that supports the small comet

"Despite all of the evidence that the atmospheric holes were a
geophysical phenomenon and not an artifact of the camera, many
members of the scientific community refused to accept the reality
of the atmospheric holes because of the immense implications of
the large fluxes of small comets in the vicinity of our planet,"
says Frank.

Frank first announced the small comet theory in 1986, after examining
images recorded in photographs taken by NASA's Dynamics
Explorer 1 spacecraft. A specially-made camera had been designed
to take pictures of the northern lights, a mission it completed
successfully when it captured the first images of the complete
ring of the northern lights from above the north pole. But some of
the images contained unexplained dark spots, or atmospheric holes.
After eliminating the possibility of equipment malfunction and
numerous other explanations, Frank and Sigwarth concluded that the
atmospheric holes represented clouds of water vapor being released
high above Earth's atmosphere by the disintegration of small ice

They calculated that about 20 comets enter the atmosphere each
minute. At that rate, the steady stream of comets would have added
about one inch of water to the Earth's oceans every 20,000 years --
enough to fill the oceans over billions of years. The theory was
immediately controversial, with people asking why such objects
hadn't been observed previously. Frank countered that not only
their small size -- 20-to-30-feet in diameter -- makes observation
difficult, but also that water striking the upper atmosphere glows
very faintly as compared to the bright glow of metal and rock in
solid meteors.

Not until the 1996 launch of Polar, with its two sensitive visible
light cameras and one far-ultraviolet light camera, was there a
chance to photograph the small comets with greater resolution.

(For further information, see the small comets web site: