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Release: Tuesday, May 26, 1998
UI's Louis Frank finds "small comets" are seasonal
IOWA CITY, Iowa -- University of Iowa space physicist Louis A. Frank
today, Tuesday, May 26, presented a new study supporting his "small
comet" theory that more than 25,000 snow comets weighing 20 to 40 tons
each disintegrate in the Earth's atmosphere every day. The study, presented
at the spring meeting of the American Geophysical Union (AGU) in Boston,
is based upon data gathered by NASA's Dynamics Explorer 1 and Polar satellites
and shows that the number of snow comets observed varies with the seasons.
Frank and his UI colleague John B. Sigwarth analyzed 1981 data collected
by Dynamics Explorer 1 and compared it to data gathered by Polar in 1997.
In both cases, they found a mid-January lull in the data, a seasonal phenomenon
that would refute the contention of some skeptics who claim that evidence
of small comets is merely electronic "noise" appearing on satellite
"We have finished our analysis of the seasonal variations during
the same months [winter], but 16 years later with the Polar spacecraft Earth
Camera. Even though the camera is totally different and the orbit is different,
the Earth Camera also detects the same seasonal variations as the Dynamics
Explorer 1 spacecraft camera, including the dramatic mid-January minimum,"
Frank says. "Obviously, the possibility of an instrument artifact
is not even remotely possible."
Despite mounting evidence supporting the small comet theory, doubters
remain in the scientific community. Several papers refuting the theory
were scheduled for presentation at the spring 1998 AGU meeting, one of them
suggesting that measurements made by another satellite show that the atmosphere
some 15 to 35 miles above the Earth is much drier than the small comet theory
Frank says that what may be needed to resolve the debate is a space mission
to meet the small comets 600 miles out. Frank, Sigwarth and a group of
former critics -- including Thomas Donahue and Michael Combi of the University
of Michigan; Paul Feldman of Johns Hopkins University; Robert Meier, George
Carruthers and Charles Brown of the Naval Research Laboratory; and Ralph
Bohlin of the Space Telescope Science Institute -- have proposed a spacecraft
to look for emissions of carbon, oxygen and simple organic gases coming
from these objects.
Last December, Frank presented a study at the AGU fall meeting showing
that dark spots (called "atmospheric holes" because of their appearance
on film) captured in June 1997 on Polar photographs decrease in size and
number as the satellite'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.
At the May 1997 AGU meeting, Frank revealed a series of Polar satellite
photographs, ranging from a picture of a small comet the size of a two-bedroom
house disintegrating thousands of 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 and built the three Visible Imaging System
(VIS ) cameras aboard Polar, offered the pictures as proof of their 12-year-old
theory, which holds that small snow comets, over the age of the Earth, could
have provided enough water to fill the oceans. Also, last August, a satellite
trailing the Space Shuttle Discovery was reported to have detected significant
amounts of high-altitude water vapor, a finding that would seem to support
the small comet theory.
Frank first announced his small comet theory in 1986, after examining
images recorded in photographs taken by Dynamics Explorer 1. Frank and
his colleagues had designed and built a specially-made camera to take pictures
of the northern lights, including 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 comets composed mostly of snow.
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. The 1996 launch of Polar, carrying two sensitive visible light
cameras and one far-ultraviolet light camera, made it possible to photograph
the small comets with greater resolution.
(For further information, see the small comets web site which is embargoed
until 1 p.m. EDT, Tuesday, May 26 at: http://smallcomets.physics.uiowa.edu/www/seasonal.html)