Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site utastro.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!qantel!lll-crg!mordor!ut-sally!utastro!dipper
From: dipper@utastro.UUCP (Debbie Byrd)
Newsgroups: net.astro
Subject: StarDate: November 23 Storms from the Sun
Message-ID: <94@utastro.UUCP>
Date: Sat, 23-Nov-85 02:00:39 EST
Article-I.D.: utastro.94
Posted: Sat Nov 23 02:00:39 1985
Date-Received: Wed, 27-Nov-85 05:14:29 EST
Organization: U. Texas, Astronomy, Austin, TX
Lines: 34

People who work in outer space have to stay alert to a kind of space
"weather forecast."  More -- in just a moment.

November 23  Storms from the Sun

Now that people are routinely working out in space, they have to get
used to new hazards -- including the threat of storms from the sun.

These storms in space are caused by solar flares -- events that take
place on the sun -- when our usually benign mother star shows an area
that's very bright in X-rays, ultraviolet and visible light.  The flare
ejects a gas cloud that travels at nearly four thousand miles per
second -- and that reaches Earth in about a day.  Then people on the
surface of Earth are treated to the sight of the aurora, or northern
and southern lights.  Meanwhile, people in Earth-orbit would be
buffeted by cosmic rays, streams of protons, and heavier nuclear
particles with enough energy to penetrate metal.

Someone working in space -- protected only by a spacesuit -- could be
made ill or even killed by radiation from a giant solar flare.
Fortunately, the flares can be seen from Earth when they occur -- and
their effects take about a day to arrive.  With plenty of warning,
space workers can take cover whenever a dangerous solar storm is on the
way.

There are fewer such storms this year than a few years ago -- because
we're close to a solar minimum -- a time in the ll-year cycle of solar
activity when that activity is at a low ebb.  The solar minimum is
predicted for l988 -- and afterwards the sun will start getting more
active again -- with an increase in sunspots and flares -- predicted to
reach another maximum in late l99l.

Script by Deborah Byrd.
(c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin