Green streaks seen in sky on Sunday likely a meteor: astronomers
09 January 2007
SINGAPORE : "If you are among many who sighted green streaks in the sky at about 7.30pm on Sunday, astronomers say you had probably seen a meteor.
James Chong could still visualise the green streak when he shut his eyes.
What he saw on Sunday evening was also spotted by many others in Singapore.
"I've seen shooting stars from the beach. It's sort of like an arc and it's glowing, but this one doesn't. It was not the same, it was green. The first time I saw it, I thought it was a plane trying to land," recounted James Chong.
But this was no plane, and experts tossed up a couple of theories.
One was that the green flash could be associated with the rising or setting sun, where the sunlight was scattered and refracted in the atmosphere, casting off a green glow.
Many astronomers here said the sightings could not have been a green flash because it lasted for some 10 seconds and presented streaks and trails in the sky. A green flash only appears for a split second.
"The timing is important. If the sun was down by the time people saw it, it probably isn't a green flash. Some people could have seen just a small dot, others a bigger area. They may have seen it through a layer of cloud," said Dr Andrew D Giger, Senior Assistant Director for Education Programmes at Singapore Science Centre.
The Astronomical Society of Singapore is certain it was a meteor.
Two of its members sighted the green light and the group plotted the south-bound trail of what they call a bolide.
Albert Lim, president of The Astronomical Society of Singapore explained: "As it moves in the atmosphere, it gets heated up because of the friction in the air molecules, resulting in the melting or destruction of the object. This leaves a bright trail, commonly called a shooting star.
"When an object is bright enough and coming at high speed, you create a much brighter shooting star which we call a fireball. When the fireball explodes in the atmosphere, it becomes a bolide."
Astronomers said meteor sightings are uncommon in Singapore due to the high level of light pollution.
For a meteor to be seen, it has to be very large and close to the brightness of the moon." - CNA /ls
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