[GTER] Explosão solar

[Gustavo Molina]

Preparem-se para eventuais blackouts em comunicação.

http://www.cnn.com/2003/TECH/space/10/28/solar.flare/

CNN)  --  One of the largest known solar flares erupted from the sun on Tuesday,
heralding a storm of superheated gas that could hit Earth within a day.

The  outburst  was  classified  an  X17.2  flare,  the  third largest on record,
according  to  Paal  Brekke, a project scientist with the Solar and Heliospheric
Observatory (SOHO), a sun-watching satellite mission jointly run by NASA and the
European Space Agency.

In  comparison,  two  solar  storms  observed  last week were between X1 and X5,
Brekke said.

Solar flares are associated with coronal mass ejections, or CMEs, eruptions from
the sun that, if headed our way, can disrupt communications satellites and power
grids.

As  this  particularly  fast-moving  CME  is  aimed directly toward Earth, it is
possible that when it arrives midday Wednesday, the geomagnetic activity will be
strong enough to stir up electrical trouble.

"The  eruption  was  positioned  perfectly.  It's  headed straight for us like a
freight  train,"  said  John Kohl, a Harvard-Smithsonian Center for Astrophysics
scientist, in a statement. "A major geomagnetic storm is bound to happen."

Brekke  is  not  so  sure  and awaits more data from SOHO and another deep space
solar-watching satellite positioned between the sun and Earth.

"Until  we know the orientation of the magnetic field in this cloud, we will not
know how severe the geomagnetic storm will be."
 
Interacting with Earth's magnetic field, the high-energy solar winds produced by
a CME often increase night displays of the northern and southern lights.

"Not  all  CMEs trigger auroras. Several, for instance, have swept past Earth in
recent  days  without  causing  widespread  displays,"  said  Tony  Phillips  of
Spaceweather.com, which monitors cosmic conditions related to the sun and Earth.

"It  all  depends  on  the  orientation  of  tangled  magnetic fields within the
electrified  cloud  of gas. This CME is no exception. It might cause auroras, or
it might not. We will find out when it arrives."

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Gustavo Molina          mailto:gustavo at molina.com.br