bcg@ncs-med.UUCP (Brian C. Grande) (10/08/85)
Hi.. I downloaded this from the local L5 modem (612-920-5566) and thought
I'd pass it along. Sorry I couldn't get it out sooner. -brian
Minnesota Starwatch is a tape recorded message describing the night sky
in the midwest, which can be called by telephone at (612) 376-5587. The
following is the text of this message for October 1985.
Hello, this is Minnesota Starwatch for October 1985. Venus is the morning
star, being prominent in the east before sunrise. On October 4 Mars will pass
close to the north of Venus. Jupiter, which has dominated the southern sky
during the summer is still very bright in the south at sunset.
The most spectacular show in the sky this month may be the Draconid
meteors, between October 7 and 10. The Draconids are produced by debris
from Comet Giacobini-Zinner, which crossed the earth's orbit during September.
Giacobini-Zinner is the comet that was recently visited by the International
Comet Explorer or ICE probe. ICE took the first direct measurements of hot gas
and magnetic fields in a comet and radioed them to scientists on earth.
Comets are chunks of ice a mile or so across with lots of dirt frozen in.
They spend most of their lives far from the sun, where it is very cold. But
whenever their motions bring them about as close as the earth is to the sun,
heat from the sun evaporates some of the comet. This mixture of vapors and
dust expands to form a large fuzzy ball around the comet nucleus. Pressure
from sunlight and a hot wind which blows outward from the sun pushes some of
this debris away to form the comet's tail. If the earth should pass behind the
comet, as happens this month with Giacobini-Zinner, we are sometimes treated to
a nice show of meteors. The dust particles from the comet which strike the
earth burn up high in the atmosphere, leaving only trails of light.
Giacobini-Zinner orbits the sun about every six and a half years, so the
Draconids meteors reach their peak on those years when the comet has just
passed into our part of the solar system.
The famous Comet Halley will, of course, be visiting us later on this
winter. Right now it is still beyond the orbit of Mars, so it has not yet
begun to form a tail. With a telescope it can be seen as a small fuzzy patch
in the club of Orion the hunter. We must wait until January to see it with our
unaided eyes.
The current show at the Minneapolis Planetarium is "Catastrophe". Show
times are Saturday and Sunday at 2:00pm. The Planetarium is located in the
main Public Library, 300 Nicollet Mall. For more information, call 372-6644.
This has been Minnesota Starwatch, produced by the University of Minnesota
Astronomy Department in cooperation with WCCO radio and television.
--
Brian C. Grande ihnp4!umn-cs!ncs-med!bcg
National Computer Systems
Health Systems Division
5700 Green Circle Drive Work 612-893-8158
Minnetonka, MN 55343 Home 612-938-2437
Land of two seasons: Winter and Road Constuction (both distroy a car!)