House-Sized Space Snowballs Said Raining On Earth

 

WASHINGTON (AP) -- Space snowballs may be pelting the Earth's atmosphere, but not in the blizzard of ice boulders proposed by a famous theory, researchers say in the latest volley between warring scientists.

 

Satellite measurements and calculations by experts suggest that the Earth's extreme upper atmosphere is too dry for there to be a constant shower from space of huge chunks of ice, scientists say in a study to be published May 14.

 

But Louis A. Frank, a University of Iowa physicist, just shrugs off the latest attack on his theory.

 

"There's no way that could be right," he said of the new study. "There are some people who are just being more emotional than scientific about this thing."

 

In the small community of atmospheric physics, emotions about Frank's theory have reached a red-in-the-face, fist-shaking level. Five other studies attacking the theory were published earlier this year and at least four papers opposing it are planned this month at an American Geophysical Union meeting in Boston.

 

But Frank is unruffled. The Iowa scientist says he has proven his case and the skeptics are just "emotional die-hards."

 

"The only thing that changes some scientists' opinion is death," he said.

 

Whoever is right, Frank said the public is fascinated by his theory and it remains a hot, controversial topic among experts.

 

Twelve years ago, Frank presented evidence that a satellite had detected what he said were house-sized chunks of ice speeding through space and colliding with the upper reaches of the atmosphere.

 

When that finding was denounced, Frank designed a camera for a new satellite and got more pictures. At a meeting of the AGU last year, he presented new pictures that showed objects streaking in from space and then ballooning into clouds some 600 to 15,000 miles above the Earth's surface. He said the objects were ice chunks weighing up to 40 tons moving at more than 20,000 miles an hour. He estimated that about 200 million tons of space ice vaporize around the Earth annually.

 

Frank said the space ice adds up to an inch of water to the planet every 20,000 years and that it may be the source of water for the Earth's oceans.

 

Many scientists at the meeting said Frank proved that comets routinely were hitting the atmosphere and some suggested it was a major new discovery. But most doubted if the comets were as big or as numerous as he claimed.

 

Researchers led by Bryan J. Hannegan of the University of California, Irvine, now say they have new proof that Frank is wrong.

 

Hannegan, lead author of a study in Geophysical Research Letters, said water measurements by another satellite show the atmosphere 15 to 35 miles above Earth is too dry to be receiving 200 million tons of water a year from space.

 

There may be space snowballs, Hannegan said, but at the very most they amount to only about 2 million tons yearly spread evenly around the planet.

 

"We can't rule out that there is water coming in from space," said Hannegan, "but we think it is about 100 times less than what Frank proposes."

 

Otherwise, he said, there would be more water vapor and other gases in the high upper atmosphere than was detected by the satellite.

 

Confronted with the study, Frank just laughed.

 

"They've tried to say that before," he said. "They're wrong. You can't just stop 20 tons of water vapor at the top of the atmosphere. It comes in at a high speed and then just plunges deep into the atmosphere."

 

Told that four more studies attacking his theory would be presented at the Boston meeting, Frank chuckled again.

 

"I'll be there," he said with a relish. "We're down to 10 or 20 skeptics and they'll never change their minds."

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