- KITCHENER - Was it a star, a comet, an asteroid or a
meteor?
-
- No, it was a fireball - probably evolved from one or
all such heavenly bodies - and it hurtled across K-W skies on Wednesday
night.
-
- It had the tail of a comet, it was bigger and brighter
than a falling star - brighter than the brightest planet, Venus, "which
is a dazzling sight these days in the morning skies,'' said Rajul Mathur,
a scientist and aerospace engineer at Com DevSpace in Cambridge, and a
member of the Royal Astronomical Society of Canada.
-
- While it may have been seen by a number of people for
about six seconds just before 10 p.m., Mathur was one of two amateur
astronomers in southern Ontario who reported the sighting to the Canadian
Fireball Reporting Centre which operates out of the University of Calgary.
The other report came from Niagara Falls.
-
- Alan Hildebrand, an associate professor in the university's
physics and science department, and co-ordinator of the centre, confirmed
yesterday that it was a fireball.
-
- "And it's possible it dropped a small meteorite,''
Hildebrand said.
-
- In case you don't know, an asteroid is a small planet
that revolves round the sun, usually between the orbits of Jupiter and
Mars, but sometimes nearer Earth's orbit. A comet is a smaller, starlike
phenomenon that doesn't go round the sun, but has an elliptical or parabolic
orbit. It's "tail'' is the sun shining on its dust particles. A meteor
is formed by dust particles given off from the comets, Mathur explained.
-
- A meteorite is a meteor that does not burn up during
its journey to earth, but survives as a small, or not so small, rock.
-
- A fireball can either be a large meteor, or it can be
a lump from an asteroid, made luminous in its journey to Earth.
-
- Mathur could not hide his enthusiasm.
-
- "It was exciting. The fireball was shaped like a
stretched balloon, with the tail narrowing rapidly, and was yellow-orange
in colour. It was much brighter than the planet Venus. I am used to seeing
stars and planets, meteors, satellites and aeroplanes in the sky, but
this light was nothing like anything I've seen before.''
-
- Mathur said he also saw the fireball extinguish itelf.
-
- Meteorites are not dangerous if small. But big ones are.
As most five-year-olds know, a huge one fell on Mexico's Yucatan peninsula
65 million years ago. The dust it generated obliterated the sun, causing
a major climate and environmental change that effectively wiped out the
dinosaur population. That crater is now covered by the ocean.
-
- There have been others in recent history. Early in the
20th century, a meteorite caused such atmospheric shock on a section
of Siberia, that miles of forest were flattened.
-
- Scientists across the world take the threat of a meteor
wipe-out seriously, Mathur said. In the U.K. a special space watch group
has been commissioned by the British government to develop an early warning
system. Rockets can be built to deflect a meteorite that could destroy
the planet simply by blocking out the sun and doing other environmental
damage.
-
- "I'm loath to say it would be the end of the world.
But it could be a very serious impact and is a very real danger,'' Mahur
said.
-
- Meanwhile, the national fireball reporting centre is
managed by a "meteorite and impacts advisory committee'' to the Canadian
Space Agency, with a mandate to investigate fireballs and recovered meteorites
in order to learn more about the solar system, Hildebrand said.
-
- The centre gets reports of about 60 to 70 fireballs a
year over the entire land mass of Canada and the U.S. But that could be
a fraction of the real number, since they could occur during the day,
over uninhabited space or the ocean, or during cloudy weather. About 7,000
meteorites reach the Earth every year, about 135 of those in Canada, Hildebrand
said.
-
-
- Torstar News Service c.1996-2001. Toronto Star Newspapers
Limited. All rights reserved.
|
