- NOAA's Space Environment Center (SEC) has classified
this flare as an X28, making it in fact the strongest ever recorded. A
source told SPACE.com that the SEC is aware other scientists still think
the flare was even stronger. The article below remains as it originally
appeared. - RRB
-
- A flare
released by the Sun on Tuesday could be the most powerful ever witnessed,
a monster X-ray eruption twice as strong as anything detected since satellites
were capable of spotting them starting in the mid-1970s
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- The strongest flares on record, in 1989 and 2001, were
rated at X20. This one is at least that powerful, scientists say. But because
it saturated the X-ray detector aboard NOAA's GOES satellite that monitors
the Sun, a full analysis has not been done.
-
- The satellite was blinded for 11 minutes. [<http://news.yahoo.com#animAnimations
below]
-
- Craig DeForest, a solar physicist at the Southwest Research
Institute, said others in his field are discussing the possibility that
Tuesday's flare was an X40.
-
- "I'd take a stand and say it appears to be about
X40 based on extrapolation of the X-ray flux into the saturated period,"
DeForest told SPACE.com.
-
- That estimate may even be conservative, he said.
-
- The flare leapt from a sunspot that is rotating off the
visible face of the Sun, so its effects were not directed squarely at Earth.
Nonetheless, a radio blackout occurred at many wavelengths as the storm's
initial radiation arrived just minutes after the eruption. Radio blackouts
are ranked from R1 to R5 by NOAA's Space Environment Center, the space
counterpart to the National Weather Service.
-
- "This is an R-5 extreme event," said SEC forecaster
Bill Murtagh. "They dont get much bigger than this."
-
- Paal Brekke, deputy project scientist for the SOHO spacecraft,
which monitors the Sun, also told SPACE.com the outburst could be as strong
as X20 "or much higher."
-
- At least X20
-
- The SEC is still evaluating the flare's ranking. For
now, they are calling it an X20+, indicating that it is indeed the most
powerful on record. The only known event that might outrank it is a 1859
solar storm that zapped telegraph lines in an era when solar monitoring
could not provide an evaluation of a flare's strength.
-
- The radiation flare was accompanied by a coronal mass
ejection (CME), an expanding cloud of charged particles -- actual matter
that moves at supersonic speeds but not as fast as light. Had this CME
been aimed at Earth, scientists would have feared a potential space storm
unlike anything seen in the Space Age.
-
- As it is, the expanding cloud is expected to provide
a glancing blow sometime Thursday.
-
- The storm, if it arrives, will not likely be major, forecasters
say. But as with all space weather, satellites and communication systems
will be at risk of disruption or damage. Colorful sky lights called auroras
may be active at high latitudes and possibly into northern U.S. states
and Europe.
-
- More to come?
-
- Tuesday's flare was generated by Sunspot 486, which is
about 15 times the size of Earth.
-
- Sunspots are dark, cooler regions of the solar surface,
areas of pent-up magnetic activity. They're a bit like caps on a shaken
soda bottle, and upwelling matter and energy can blow at any moment. Scientists
cannot predict when a flare will occur.
-
- During the past two weeks, number 486 and two other large
sunspots set off nine other major flares. It was one of the stormiest periods
of activity ever witnessed, all experts agree. The number of intense flares,
some shooting out within a day of another, was unprecedented. Auroras were
seen as far south as Texas and Florida.
-
- The second strongest flare in this historic two-week
series was an X17 event on Oct. 28. It was aimed at Earth and generated
severe geomagnetic storming when it blew past the planet less than 24 hours
later.
-
- A period of relative calm is now expected on the solar
surface. But another round is possible.
-
- The Sun spins once on its axis once every 25 days at
its equator, carrying sunspots around. Sunspots can last days or weeks.
Any of the three that have rotated off the right side of the Sun could
return in about two weeks on the left side and, possibly, send more major
storms toward Earth.
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- Copyright © 2003
- http://us.rd.yahoo.com/dailynews/space/SIG=grdpua/*http://www.SPACE.com/
SPACE.com.
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