Starship Asterisk*

geckzilla wrote:I think it's because the hole punch managed to happen on somewhat thicker clouds than the usual photos. I dunno though. It looks similar enough to me to dismiss any extraterrestrial origins.

Chris Peterson wrote:most of the nutcases are claiming the thing is of extraterrestrial origins.

HAARP, of course, is a favorite of the conspiracy nuts.

mark swain wrote:People who claim to have seen ufo,s should not be called nuts.. one day ,, I am sure,, they will regret them statements.

Chris Peterson wrote:I do, however, use the term for people who see them regularly, and believe them to be extraterrestrial spacecraft.

It is certain beyond reasonable doubt that we are not being visited by aliens.

mark swain wrote:So how could it be comprehended in the 14th century?

mark swain wrote:So Send these guys a message Chris

http://en.wikipedia.org/wiki/Communicat ... telligence

Why Bother?

mark swain wrote:I am no Nut

As turboprop and jet aircraft climb or descend under certain atmospheric conditions, they can inadvertently "seed" mid-level clouds, causing narrow bands of snow or rain to develop and fall to the ground, new research finds.

Through this seeding process, the aircraft leave behind odd-shaped holes or channels in the clouds that have long fascinated the public.

The key ingredient for developing these holes in the clouds: water droplets at subfreezing temperatures, below about 5 degrees Fahrenheit (-15 degrees Celsius).

As air is cooled behind aircraft propellers or over jet wings, the water droplets freeze and drop toward Earth.
...
A similar process can occur with jet aircraft, which need colder temperatures (below about -4 to -13 degrees F, or -20 to -25 degrees C) to generate the seeding effect. Air is forced to expand over the wings as the aircraft moves forward, cools, and freezes the cloud droplets.

Precipitation from planes may be particularly common in regions such as the Pacific Northwest and western Europe because of the frequent occurrence of cloud layers with supercooled droplets, Heymsfield says.

Results of the study, which addressed long-standing questions about unusual cloud formations known as hole-punch and canal clouds, are published this month in the Bulletin of the American Meteorological Society.
...
Across the world, sightings of blue-sky holes piercing a cloud layer have triggered bemusement and speculation.

A front-page feature on Yahoo! carried the headline "A Halo over Moscow" after photos emerged of just such a hole in October 2009.

• Bulletin of the American Meteorological Society,
  June 2010, doi: 10.1175/2009BAMS2905.1 (PDF)

Aircraft can accidentally punch holes in clouds, leaving a trail of snow or rain in their wake, a new study finds.

Turboprop and jet aircraft that climb or descend under certain atmospheric conditions can inadvertently trigger what's known as cloud seeding. This technology is usually associated with schemes to control the weather. However, cloud seeding can happen by accident as planes soaring through mid-level clouds leave behind odd-shaped holes or channels in the clouds and cause narrow bands of snow or rain to develop and fall to the ground.

Holes punched in clouds are a phenomenon that has been recognized for many years and seen in photos from around the world. A front-page feature on Yahoo! carried the headline "A Halo over Moscow" after photos emerged of just such a hole in October 2009.

The secret behind these mysterious clouds has now been revealed: Supercooled water droplets that remain liquid even at subfreezing temperatures — below about 5 degrees Fahrenheit (minus 15 degrees Celsius). When an airplane cuts through clouds containing the supercooled water droplets, air is cooled behind aircraft propellers or over jet wings, and these water droplets freeze and drop toward Earth.

How do you punch a hole in a cloud? Fly through it.

Meteorologists had long figured that aircraft were part of the explanation for crazy-looking “hole-punch clouds” like this one. When propeller planes fly through a cloud, they thought, it can exert air pressure that cools water extremely quickly to produce ice. If water vapor condenses on that ice, snow falls from the sky and leaves a conspicuous cloud hole.

Now, thanks to a happy accident, researchers confirmed that planes can cause these cloud holes, and that even jets, not just prop planes, can do it.

Andrew Heymsfield, a scientist with the National Center for Atmospheric Research, was aboard a research plane near the Denver airport in 2007 when he unwittingly flew through a flurry of snow produced by a hole-punch cloud.

The plane was loaded with instruments for studying how ice forms in clouds. Radar from the ground picked up a strange echo in their wake, indicating oddly-shaped snowflakes. “We didn’t know it, but we went right through this precipitation feature that was spotted from the ground,” Heymsfield said [Wired].

Their readings, when matched up with the path of planes in the area, helped unravel the mystery:

The researchers then linked satellite images of hole-punch clouds to flight schedules to show that jet aircraft, not just propeller planes, can also punch holes and produce snow. The supercooled droplets freeze after passing over the jet planes’ wings, Heymsfield said [Wired].

Their work will soon be published in the Bulletin of the American Meteorological Society.

A new study spawned by the accidental discovery solves the mystery behind so-called hole-punch clouds and explains how airplanes can change the weather, at least on an extremely local level.

As planes push cloud temperatures past the tipping point at which supercooled water freezes, the aircraft "seed" the clouds with ice particles, the study says.

A new study spawned by the accidental discovery solves the mystery behind so-called hole-punch clouds and explains how airplanes can change the weather, at least on an extremely local level.

Because the water in these clouds is so pure—with no particles around which vapor can condense and freeze—the droplets remain liquid down to minus 35 degrees Fahrenheit (minus 34 degrees C). If the cloud gets much colder, though, they freeze into ice particles that can produce rain or snow.

When a plane's propeller, for example, spins through a cloud, the propeller exerts a rearward force. The force expands air, cooling by as much as 54 degrees Fahrenheit (30 degrees Celsius)...

As planes push cloud temperatures past the tipping point at which supercooled water freezes, the aircraft "seed" the clouds with ice particles, the study says.