From: LARRY KLAES (ljk4_at_msn.com)
Date: Tue Jan 07 2003 - 10:55:33 PST
----- Original Message -----
From: Ron Baalke - Near-Earth Object Program
Sent: Tuesday, January 07, 2003 12:38 PM
To: ljk4_at_msn.com
Subject: Extrasolar Meteors Hint A Distant Planet Formation
Forwarded to you courtest of NASA's Near-Earth Object Program.
http://www.newsandevents.utoronto.ca/bin4/030106a.asp
Extrasolar meteors hint at distant planet formation
Radar telecopes could trace dust grains back to neighbouring solar systems
by Nicolle Wahl
University of Toronto
January 6, 2003
University of Toronto astronomers say that detecting microscopic meteors
from other solar systems could provide clues about the formation of planets
like Earth.
Dust streams from our sun's stellar neighbours consist of tiny grains of
pulverized rock ejected from a disk of dust and debris that commonly
surrounds young stars, says Joseph Weingartner, a post-doctoral fellow at
U of T's Canadian Institute for Theoretical Astrophysics. According to
Professor Norman Murray, associate director of CITA and co-author of the
study, "if we can detect these grains and trace them back to the star
system that they came from, we'd have very good evidence of planet
formation going on in that system." Weingartner presented the study
Jan. 6 at the American Astronomical Society meeting in Seattle, Wash.
The tiny grains are created by collisions of large objects such as
boulders and asteroids during or slightly after the process of planet
formation, he explains. The collisions create a disk of particulate
grains (each grain is about 100 times smaller than a grain of sand).
Some of these grains are then ejected from a disk after "slingshotting"
around a planet. Weingartner says the speeds of the grains entering our
solar system can range from a few kilometers to 100 kilometres per second.
If the grains are travelling at high velocities, researchers know that they
originate from outside our solar system.
Weingartner and Murray propose that future radar telescope facilities that
can examine roughly one million square kilometers of space be used to detect
dust streams coming from nearby stars. By detecting the speed and direction
of grains when they hit the Earth's atmosphere, scientists could potentially
trace the path of the tiny grains back to star systems where planet
formation may be occurring.
"In astronomy, if you want information, you always rely on radiation like
visible light or infrared light," says Weingartner. "You can think of these
radar facilities as a different type of telescope - a telescope for
collecting dust rather than a telescope for collecting light."
Among the star systems whose dust streams could be studied is beta Pictoris,
a 10-to-20 million-year-old star located roughly 63 light years from the sun.
Weingartner and Murray estimate that in the dust disk around beta Pictoris,
the mass of the particles with a radius of one centimeter or smaller is about
19 times the mass of the Moon.
"We have a real opportunity to open a new window on these kinds of systems,"
says Weingartner. He and Murray say that their study is a first step in a new
approach to astronomical research, and note that further studies will require
the construction of large radar telescope facilities with expanded sky coverage.
The study was funded by the Natural Sciences and Engineering Research Council
of Canada.
Nicolle Wahl is a news services officer with the department of public affairs.
CONTACT:
Joseph Weingartner, CITA ph: (416) 978-8497; email: weingart_at_citautoronto.ca
Norman Murray, CITA, ph: (416) 978-1778; email:
murray_at_cita.utoronto.ca, (Available Jan. 7)
U of T Public Affairs, ph: (416) 978-6974; email: nicolle.wahl_at_utoronto.ca
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