'99 LEONID METEOR WATCH
AN EXPANDED EFFORT

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University of Western Ontario (UWO), London, Ontario, Canada

Dept. of Communications and Public Affairs
University of Western Ontario (UWO)
London, Ontario, Canada  N6A 5B8
Tel. (519)661-2045   Fax: (519)661-3921
http://www.uwo.ca


FOR IMMEDIATE RELEASE: October 25, 1999


'99 LEONID METEOR WATCH AN EXPANDED EFFORT


A team of UWO researchers is stepping up its efforts this year to monitor
November's rare and potentially-hazardous Leonid meteor stream.


The stream, scheduled to pass through the Earth's atmosphere on Nov. 17 and
18, could produce hundreds to thousands of meteors per hour. A potential
storm component may result in much higher rates -- causing a spectacular
display of faint meteors in some parts of the world but also a potential
risk to any of the close to 600 operational satellites orbiting Earth.


"The Leonid shower hits its peak every 33 years and this is the peak year,"
says team member Margaret Campbell, a PhD student in physics and astronomy.


The UWO team led a monitoring effort from Mongolia and Australia last year
as a lead-up to this year's anticipated larger storm.


With financial and logistical backing from the U.S. Air Force, NASA, the
Canadian Space Agency, Canada's Department of National Defence, and the
European Space Agency, the researchers are setting up monitoring sites in
seven locations around the world.


Kerry Ellis, a UWO graduate, will operate an Australian-built radar that
uses high-tech Canadian-designed and constructed radar antennas that will
monitor the Leonid stream from Alert, Nunavut. Special electro-optical video
equipment will be set up at sites in Hawaii, Florida, the Canary Islands,
Kwajalain Atoll in the Marshall Islands and at two sites in the Negev
Desert, Israel to record the storm as it develops. The data collected from
these seven sites will be transferred to a communications centre at NASA's
Marshall Space Flight Centre in Huntsville, Alabama. From Alabama, NASA and
UWO researchers will compile and profile the data so government, military
and commercial satellite operators can access it.


Physics and astronomy professor Jim Jones together with engineering professor
Alan Webster and UWO graduate Bruce McIntosh will help lead the NASA team in
Alabama. Professor Robert Hawkes of Mount Allison University and UWO physics
and astronomy graduate students Margaret Campbell and Simona Nikolova will
manage the sites in Israel.


Peter Brown, a physics and astronomy research associate at Western, is
the overall project manager for the monitoring effort. He will be at the
observation site in the Canary Islands during the storm.


Brown stresses the long-term objective of the meteor watch is to gain better
insight into how comets and meteoroids streams form and evolve.


"Comets are made of materials formed long before life existed on Earth," he
says. "Understanding them may help us understand how life evolved on our
planet."


The monitoring sites were chosen because they lie along what is expected to
be the best longitude for viewing. The storm is predicted to peak at
approximately 9:20 p.m. EST on Nov. 17.


Sky watchers shouldn't expect to see much activity in southern Ontario
however, says Brown.


"We're not in a good location for viewing," he says. "While this year's
storm is expected to present a higher risk to satellites, it is largely
because there are more small particles. That means fewer bright fireballs,
even for people in the best geographical location."


Campbell will travel to Israel on Nov. 10 to set up the sites there. Brown
will depart for the Canary Islands on Nov. 11. Other scientists from around
the world will be involved at all sites.


For more information, Margaret Campbell can be reached until Nov. 10 at
(519) 850-2385. Peter Brown can be reached between Oct. 29 and Nov. 11 at
(519) 661-2111 ext. 86458. Judy Noordermeer, Communications and Public
Affairs, can be contacted at (519) 661-2111 ext. 85468.


Attention Broadcasters: Western has installed Bell's VideoROUTE service that
allows for live or pre-taped broadcast interviews with television studios.
To arrange to interview the experts on this story using this service, please
call (519) 661-2111 ext. 85468 or ext. 85165. A 30-second Betacam animation
clip of the comet and storm is also available.


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                     QUESTIONS AND ANSWERS


What is the difference between a meteor, a meteoroid and a meteorite?


A meteoroid is any solid particle larger than a molecule and smaller than an
asteroid which is in orbit about the sun. When a meteoroid collides with the
Earth, the frictional heating with the Earth's upper atmosphere produces
light, heat and (for deeply penetrating meteoroids) sound phenomena called
a meteor. If a meteoroid is large enough to survive its passage through the
atmosphere as a ponderable mass it is termed a meteorite. The Leonid shower
does not produce meteorites as the meteoroids move too fast to allow any
material to survive.


What is a meteor shower?


A meteor shower occurs when the Earth, in its annual journey around the Sun,
passes through a stream of dust particles (called a meteoroid stream) strewn
along the path of a comet. Dust particles from the stream collide with the
Earth's upper atmosphere at speeds of up to 72 kilometres per second (260
times the speed of sound) and are rapidly vaporized at heights between 80
and 120 kilometres above the ground, producing the brief streaks of light
that we call a meteor shower.


What is the Leonid Meteor Shower?


First reported by Chinese astronomers in 902 A.D., the Leonid meteor shower
is so named because it appears to radiate from the constellation Leo. It is
normally observed every year between November 14 and 20 during which time as
many as 20 meteors are visible each hour. However, the shower is most famous
for the periods of much greater activity that have, with a few exceptions,
occurred at intervals of about 33 years. This is a year in which greater
activity is possible.


At its peak this year on Nov. 17, hundreds to thousands of meteors an hour
could hurtle through the sky. Although most meteoroids will be no larger
than a grain of sand, the shower has been so active in the past that it has
taken on the appearance of falling snow.


What's the difference between the '99 Leonid storm and the '98 Leonid storm?


This year's storm will almost certainly be as intense, or more intense than
last year -- this is the peak of its 33-year cycle. While the meteoroids
will be smaller this year, the risk to satellites will be greater because
of their greatly increased numbers. Smaller particles also mean there will
be fewer bright fireballs than were seen last year.


What's the danger?


Although small, the meteoroids are moving so fast that they possess a great
deal of energy. They could poke holes in solar panels, pit lenses, blast
reflective coating off mirrors, short out electronics with a burst of
electromagnetic energy, or even damage computers on satellites. While some
military satellites are better shielded because they are built to withstand
nuclear assault, other spacecraft are not as protected.


In Canada, for example, damage to any of the Anik satellites might shut down
TV transmission, some telephone service, electronic banking, and airline and
travel reservation systems. The Leonids could also harm the American Hubble
space telescope and the Russian space station Mir, for example.


Why monitor the shower from Israel, Hawaii, Florida, the Marshall Islands
and the Canary Islands?


The Leonid meteor shower will be most intense across the longitudes of
Israel and the Canary Islands. The other sites cover a wide spread in
longitudes, allowing observation of the shower for 18 continuous hours,
even though it will be up in darkness for only about six hours from any
individual site. These locations also have a good probability of clear
skies -- necessary for the electro-optical equipment. The radar has been
set up in Alert because the shower will be visible 24 hours a day there.
Alert is also too far north for aurora, which interfere strongly with radar
observations.


Will we see the Leonids in Southern Ontario?


Southern Ontario is not a good viewing location for the Leonid meteor shower.
The shower will be strongest around the longitudes of Europe and the Middle
East; however, Europe has a low chance of clear skies in mid-November, so it
is not the best observing location.


What scientific questions can meteor monitoring answer?


The long-term objective of the Leonid meteor watch is to gain better insight
into how comets and meteoroid streams form and evolve. Comets are made up
of material originating from a halo of ice and dust that has surrounded the
solar system long before life existed on Earth. Understanding them may help
scientists understand how life evolved on our planet.


How will we know if satellites are at risk of being hit?


The real-time reporting system being coordinated through NASA's Marshall
Space Flight Centre in Huntsville, Alabama will be the only coordinated,
multi-instrument means of providing immediate warning about the shower
strength and severity. By analyzing the strength of the shower in
real-time, scientists will be able to provide some advanced warning about
the most probable time for the showers peak and, less reliably, its peak
strength.


Who are the members of the research team at The University of Western
Ontario?


* Dr. Peter Brown, research associate, physics and astronomy -- project
  manager
* Dr. Jim Jones, professor of physics and astronomy -- principal
  investigator
* Dr. Alan Webster, professor of engineering science -- co-investigator
* Margaret Campbell, PhD student in physics and astronomy
* Simona Nikolova, master's student in physics and astronomy
* Dr. Wayne Hocking, professor of physics and astronomy


With help from:
* Dr. Kerry Ellis, Communications Research Centre, Ottawa
* Dr. Bruce McIntosh, formerly of the National Research Council, Ottawa

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This page was last modified on November 10, 1999 by Casper ter Kuile, Carl Johannink, Hans Betlem