10 kg Ice Blocks From the Sky

THE ICE BLOCKS tend to weigh more than 22 pounds (10 kilograms) and have been known to leave 5-foot (1.5-meter) holes in houses. Martinez-Frias fears that the formation of these hailstonelike blocks on clear days could be a worrying symptom of climate change.

“I’m not worried that a block of ice might fall on your head ... but that great blocks of ice are forming where they shouldn’t exist,” said Martinez-Frias, director of planetary geography at Spain’s Astrobiology Center in Madrid.

“Components of the atmosphere, like ozone and water, are changing in different levels of the atmosphere. ... We think these signs could be evidence of climate change,” he said in a telephone interview with Reuters.

While Martinez-Frias said he was far from certain as to why the ice meteors formed, he said they were neither hoaxes nor blocks of ice falling from the bars or bathrooms of passing aircraft, as skeptics have suggested.

“We’re not talking about hoaxes,” Martinez-Frias said. “It’s very easy to tell real and false ice blocks apart.”

“It’s not water from airplane toilets. ... Its isotopic composition bears the signature ... of Iberian rain.”

SMASHING WINDSHIELDS

Ice clouds made from crystallized vapor trails of aircraft are well-known to pilots, but Martinez-Frias suggests that because global warming involves one level of the atmosphere getting colder while another gets hotter, some ice clouds now remain longer.

Their centers then fall through the atmosphere, bouncing and gathering mass, to end up smashing through a car windshield or, more usually, landing softly in a field, he suggested.

The first megacryometeor found this year in Spain — by a startled farmer riding his tractor in Soria — weighed 35.27 pounds (16 kilograms).

Three others were found later, bringing the world total over the last decade to more than 50. But Martinez-Frias said only around a fifth of the ice meteors are ever found.

An ice meteor weighing around 440 pounds (200 kilograms) has been found in Brazil, Martinez-Frias said. Other blocks have been found in Mexico and Australia.

ICE ON A CLEAR DAY?

The blocks form 2.5 to 6 miles (4 to 10 kilometers) above ground, he said.

Some scientists doubt whether hail can form on a clear day.

“Solid ice cannot form in the absence of thick, highly visible clouds,” Charles Knight, a hail expert at the University Corporation for Atmospheric Research in Boulder, Colo., was quoted as saying in a supplement of the journal Science.

But geologist Roger Buick of the University of Washington in Seattle told the same publication that a model created by Martinez-Frias and his team showing ice can form on a clear day was an “important advance in that it thoroughly documents and provides an explanation for a spectacular phenomenon.”

The Original Story from: msnbc.com