Don't panic over meteor - astronomer
2013-03-13 12:02
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Cape Town - The meteor that streaked across the sky over Cape Town is no cause for alarm because of its size, an astronomer has said.
"It's probably something like a pebble-sized piece of rock," Dr Nicola Loaring, outreach astronomer at the South African Astronomical Observatory, told News24.
She confirmed that based on reports, the object could be classed as a meteor.
"I've had about six reports in and just from those eyewitnesses; their descriptions - they described a bright white light with a white tail that shot across the sky in a couple of seconds - to me, personally, that definitely sounds like a meteor."
Meteor showers are often the result of the Earth passing through comet debris and the light show that results is when particles enter the Earth's atmosphere and burn up on their way.
Comet debris
"The streak of light you see is actually emitted from the atmosphere and not the pebble or dust itself. The pebble travels so fast with so much energy that it excites the atmosphere, and when the atmosphere goes back to normal again, it has to get rid of that energy so it gives off energy in the form of light," said Loaring.
The gamma-Normid meteor is scheduled to peak around 15 March, but Loaring expressed doubt that the object seen on Tuesday could be related to this shower.
"Usually, when you've got a meteor shower, you have a number of meteors and they all appear to come from a particular constellation - in this case it would be the Norma constellation. This meteor may or may not be associated with the shower however the shower is best viewed looking south-east toward the constellation Norma between midnight and four am," she said.
Another astronomer explained that meteor showers are often the result comet debris.
"Basically what happens is that the comet breaks up and then the debris from the broken up comet spreads along its orbit. If it crosses Earth's orbit, we'll experience a meteor shower," said Dr Sarah Blyth of UCT.
Blyth will be one of the first astronomers to lead a team investigation using the MeerKAT (Karoo Array Telescope) in the Northern Cape province.
Common
Russia experienced a spectacular meteor display recently when an object left a trail of destruction as it sped through the atmosphere.
Around 1 200 people were injured, mainly from broken glass.
Loaring assured the public that meteors are fairly common, but conceded that the brightness of the object estimated to be the size of a pebble might have been cause for some concern.
"The brighter ones are rarer and people saw that. Because of Russia being fresh in their minds, I think people did kind of worry a little bit."
Given the size of the object, it is unlikely that any physical trace could be found, Loaring added.
"People were asking where it landed and I've had no reports of anything landing."
The next major meteor shower is the Lyrids expected to start from 16 April, and peak on 22 April.
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