A rare show up in the sky

KK folk see rare halo over city

12-10-2007 10:39:43 AM

KOTA KINABALU: They looked up at the sky hoping to see Dr Sheikh Muszaphar Shukor's spacecraft but instead saw a halo formed by a rare weather phenomenon.

As word spread about the halo's appearance at 11am, people stopped along sidewalks and looked up.

Some took out their camera-equipped handphones to capture the scene. The halo was visible for about two hours.

A Meteorological Department official said a halo would occur two to three times a year under certain atmospheric conditions.

“They include the presence of cirrus clouds at very high altitudes, about five to 10km above sea level,” he said.

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And according to the Daily Express reports, a mysterious white object was seen moving very fast! Yet they still managed to capture it using Nokia E61i handphone (iklan! iklan!).

A halo - and with it a puzzle...

Kota Kinabalu: A circular sun halo hovered over the noon skies of the State Capital Wednesday, prompting many to call the Daily Express office as to what it may portend.

In scientific terms what they saw was simply a "prism effect" of millions or may be billions of very small ice crystals that compose high altitude cirrus clouds - thin wispy clouds that are typically found at 20,000ft (6,000m).

Clouds are essentially micro water droplets but because of their extraordinary high level, these ice crystals that compose cirrus clouds originate from the freezing of super-cooled water droplets.

What was even more captivating about the phenomena and which could not be seen by the naked eye was captured by Sabah Publishing House Managing Director Datuk Clement Yeh on his Nokia E61i at around that time in Tanjung Aru.

Clement did not want to hurt his eyes and started clicking away the halo on his handphone camera placed on his outstretched palm. As it turned out, he not only captured the halo on camera but also a mysterious white speck.

"It was only on reviewing the images later that I noticed this white speck or dot. Even then, I did not think much of it as it could easily be a speck of dust on the camera lens.

"I then decided to zoom in on the speck and noticed that it was not stationary but seemed to have been in motion in a linear fashion suggesting that whatever it is, it had obviously been moving at high speed."

A professional photographer, he does not think it is a reflection on his phone lens since it was not stationary.

At this point in time, nobody is able to explain what it is but we provide these images that Clement took for the public to decide or even speculate.

Back to the sun halo, this phenomenon is fairly common among the cirrus clouds and may cause three types of effects. One, a circular halo that looks like a rainbow like the one seen above KK.

The second type of halo features a sun-dog coloured image of the sun as a bright spot in the lower left while a third type may take the form of a tangential arc - a second curve near the top of the circular halo.

Physics students would probably understand the slightly complex phenomenon better.

The circular halo is said to be formed by pencil-like (angular-shaped) ice crystals which are all falling from the sky at a rate slower than raindrops and oriented horizontally simply because that's how things fall due to air friction.

But the horizontal orientation is random and so any crystal that formed the proper angle relative to the observer and the sun bends the sunlight at a 22 degree angle thus forming a circle 22 degrees to the sun.