-Caveat Lector-
Severe solar storm
sparks an alert
By Robert Roy Britt and Jim Banke
SPACE.COM Nov. 9 - A severe space weather storm began pounding Earth late
Wednesday and is expected to threaten communications, satellite operations
and possibly astronauts and airline passengers - especially pregnant women -
through Sunday. Montana State University physicist Richard Canfield
narrates an animation explaining how solar storms affect Earth.
THE EVENT began Wednesday at 6:50 p.m. ET, when a large solar flare
welled up from deep within the sun. This energy interacted with the solar
atmosphere, sending a stream of charged particles called protons heading
toward Earth.
"The protons measured near Earth increased 10,000 times in the matter
of a few minutes," said Joseph Kunches, lead forecaster at the National
Oceanic and Atmospheric Administration's Space Environment Center.
Forecasters labeled the event an S4. The most severe would be an S5.
The event was different from other recent solar storms - less likely to
generate an increase in the northern lights, forecasters said. But at the
same time it's potentially more dangerous to humans.
The protons buffeting Earth are a form of radiation that, with
extended exposure, is thought to damage DNA and contribute to cancer. While
cosmic radiation from distant sources constantly bombards Earth, the amount
increases during a severe solar storm.
People on the ground are not at risk, as Earth's magnetic field and
atmosphere provide a blanket of protection.
NOAA says an airline passenger could experience as much radiation as
10 chest X-rays, though this figure is debated. Experts do agree, however,
that anyone on a high-altitude jet or in space is exposed to more radiation
than someone on the ground.
MOST NEEDN'T CHANGE PLANS
Wallace Friedberg, who studies the threat for the Federal Aviation
Administration, said that the NOAA estimates are the best available. He said
most people planning a flight during the storm should not necessarily change
their plans, adding that the radiation measurements he has seen indicate
that this event is not the worst possible.
"If it was my daughter, and if she was pregnant, I'd tell her she
might want to wait," said Friedberg, who heads the radiobiology research
team at the FAA Civil Aeromedical Institute. "If she's not pregnant, I
wouldn't be that concerned."
Friedberg has a short flight scheduled himself this weekend. "If I
was going today, I would go," he said. "But I'm not pregnant."
High-frequency radio communications will also be strongly affected
through Sunday, when the proton stream is expected to die down.
The proton stream would be strong enough to be dangerous to
astronauts if they are on spacewalks. There are three people - one American
and two Russians, living aboard the international Space Station Alpha.
"NASA is acutely aware of the fact that there is some hazard to them
based on the radiation environment," said NOAA's Kunches. "And today is one
of those days that they need to worry."
NASA says the three crew members aboard Alpha are in no danger from
the event.
However, flight controllers near Moscow have asked station commander
Bill Shepherd and cosmonauts Yuri Gidzenko and Sergei Krikalev to set up a
radiation-monitoring device inside the Russian-built modules as a
precaution.
The portable device, similar to those used during each space shuttle
mission, will sound an alarm if it senses radiation that reaches a preset
level, said NASA spokesman Rob Navias.
If that should happen, the three crew members will move to the end of
the Zvezda service module, where the Soyuz spacecraft is docked, and remain
there until the radiation level subsides. This part of Space Station Alpha
offers the most protection from the hazard, Navias said.
In any case there is no need for Shepherd, Gidzenko and Krikalev to
move into the Soyuz for protection, nor are there any plans for the crew to
evacuate the station and return to Earth. Space Weather Scale
The National Oceanic and Atmospheric Administration has set up three scales
to measure the severity of "space weather."
Click on a category above to see what effects each level of space storm can
create:
G5: Extreme. Collapse of power grid systems, damage to transformers,
satellite link problems, radio disruption.
G4: Severe. Potential problems with stability of power grids, satellite
corrections needed, radio communications affected.
G3: Strong. Voltage corrections required, false alarms triggered on
protection devices, satellite problems, intermittent radio problems.
G2: Moderate. High-latitude power systems affected, possible effect on
satellite orbits, fading in high-frequency radio signals at high latitudes.
G1: Minor. Weak power grid fluctuations, minor impact on satellite
operations, migratory animals begin to be affected.
S5: Extreme. High radiation hazard for spacewalkers. Passengers in
high-flying aircraft at high latitudes may receive radiation dose equivalent
to chest X-ray. Some satellites lost. No high-frequency communications
possible in polar regions.
S4: Severe. Radiation hazard for spacewalkers. Satellites encounter
problems. Some blackouts in high-frequency communications in polar regions.
S3: Strong. Spacewalkers should take measures to avoid radiation hazard.
Single-event satellite upsets. Degraded high-frequency communications in
polar regions.
S2: Moderate. No biological impact. Infrequent single-event satellite
upsets. Small effects on high-frequency communications.
S1: Minor. No biological impact. No impact on satellite operations. Minor
impact on high-frequency radio in polar regions.
R5: Extreme. Complete high-frequency radio blackout on Earth's sunlit side
for several hours. Low-frequency outages. Increased navigation errors.
R4: Severe. High-frequency radio blackout for one or two hours, affecting
most of Earth's sunlit side. Low-frequency outages. Minor disruptions in
satellite navigation systems.
R3: Strong. Wide-area blackout of high-frequency radio on sunlit side.
Low-frequency signals degraded for about an hour, affecting navigation
systems.
R2: Moderate. Limited blackouts of high-frequency radio on sunlit side.
Low-frequency navigation signals degraded for tens of minutes.
R1: Minor. Minor degradation of high-frequency radio on sunlit side.
Low-frequency navigation signals degraded for brief intervals.
"This particular solar flare, even if it reaches the levels that
would trigger that alarm on board, would have no impact to crew health or
crew safety," Navias said.
But the long-term effects of exposure to cosmic radiation and solar
storms are more worrisome, and not entirely known.
NASA keeps an eye on the amount of radiation an astronaut accumulates
during several missions, and once they hit their limit they can't fly
anymore. What that limit is depends on each crew member, and because of
medical privacy it's never been publicly announced that an astronaut won't
fly because of radiation concerns.
DEBATE OVER AIR PASSENGERS
Scientists have known for nearly a century that the effects of
radiation increase with altitude.
There is debate over how much danger an event of this type poses to
airline passengers. But experts agree that any potential danger depends on
the route of the plane.
"If you fly from Philadelphia to Atlanta, it probably isn't going to have
any effect on you," said Kunches, the NOAA forecaster. "Flights in the polar
regions are going to be much more susceptible to seeing some effects."
Other scientists say the amount of radiation in the atmosphere can be
twice as much at the poles as elsewhere. This is because Earth's magnetic
field channels incoming energy toward the poles.
Even on normal flights in non-storm conditions, researchers say the
risk to unborn babies might be too great if a pregnant women takes frequent,
long flights.
The solar flare also triggered what scientists call a coronal mass
ejection. Energy from this type of event takes two to three days to reach
Earth, and fuels the colorful displays called the northern or southern
lights, or aurora. This storm was not expected to cause significant auroral
activity, however.
"The likelihood of a big magnetic storm is pretty low," Kunches said.
"It looks like most of the brunt of the material and the energy is going to
go off the west limb [of the sun] and away from the earth."
� 2000 Space.com. All rights reserved.
<A HREF="http://www.ctrl.org/">www.ctrl.org</A>
DECLARATION & DISCLAIMER
==========
CTRL is a discussion & informational exchange list. Proselytizing propagandic
screeds are unwelcomed. Substance�not soap-boxing�please! These are
sordid matters and 'conspiracy theory'�with its many half-truths, mis-
directions and outright frauds�is used politically by different groups with
major and minor effects spread throughout the spectrum of time and thought.
That being said, CTRLgives no endorsement to the validity of posts, and
always suggests to readers; be wary of what you read. CTRL gives no
credence to Holocaust denial and nazi's need not apply.
Let us please be civil and as always, Caveat Lector.
========================================================================
Archives Available at:
http://peach.ease.lsoft.com/archives/ctrl.html
<A HREF="http://peach.ease.lsoft.com/archives/ctrl.html">Archives of
[EMAIL PROTECTED]</A>
http:[EMAIL PROTECTED]/
<A HREF="http:[EMAIL PROTECTED]/">ctrl</A>
========================================================================
To subscribe to Conspiracy Theory Research List[CTRL] send email:
SUBSCRIBE CTRL [to:] [EMAIL PROTECTED]
To UNsubscribe to Conspiracy Theory Research List[CTRL] send email:
SIGNOFF CTRL [to:] [EMAIL PROTECTED]
Om
