http://www.westender.com.au/stories.php?s_id=376


Sun unleashes major solar flare
- Dave Reneke
The Sun is just past its low-point in
an 11-year cycle of activity. But big eruptions can happen anytime. One
just did.


A major X-9 flare erupted last week. It
emanated from a large sunspot, numbered 929, which is just coming into
view around the eastern limb of the Sun.

The flare lifted off the Sun and was
directed away from Earth. But this sunspot will rotate toward the
centre of the Sun over the next few days and could offer up more major
blasts that could take direct aim at our planet, forecasters say. It
may cause auroras in Tasmania later this week.

Flares of this magnitude (X-class flares
are all major) can damage satellites and disrupt telecommunications on
Earth. They can also threaten astronauts in space.

NASA sometimes orders astronauts aboard
the International Space Station to retreat to the most well protected
part of the orbiting outpost to avoid excess radiation exposure.
Spacewalks are avoided during solar storms.

Sunspots are dark regions of the Sun
where intense magnetic activity caps the upwelling of material from
below. Sometimes a cap blows, and a visible flare results. The flares
are loaded with X-rays and other radiation, all of which reaches Earth
moments after the eruption and can be accompanied by a shower of
protons.

These storms can arrive in moments with
little warning and can be deadly. Many flares are accompanied by clouds
of electrified gas called coronal mass ejections, which can slam Earth
a day or so later.

Earth is somewhat shielded from solar
storms, but some of the radiation leaks through our protective magnetic
field. Experts say space radiation is one of the biggest threats to
current and future space missions, including the effort to establish a
lunar base.

NASA.


Dave Reneke
News Editor

http://www.westender.com.au/stories.php?s_id=376


Sun unleashes major solar flare
- Dave Reneke
The Sun is just past its low-point in an
11-year cycle of activity. But big eruptions can happen anytime. One just
did.


A major X-9 flare erupted last week. It
emanated from a large sunspot, numbered 929, which is just coming into
view around the eastern limb of the Sun.

The flare lifted off the Sun and was
directed away from Earth. But this sunspot will rotate toward the centre
of the Sun over the next few days and could offer up more major blasts
that could take direct aim at our planet, forecasters say. It may cause
auroras in Tasmania later this week.

Flares of this magnitude (X-class flares are
all major) can damage satellites and disrupt telecommunications on Earth.
They can also threaten astronauts in space.

NASA sometimes orders astronauts aboard the
International Space Station to retreat to the most well protected part of
the orbiting outpost to avoid excess radiation exposure. Spacewalks are
avoided during solar storms.

Sunspots are dark regions of the Sun where
intense magnetic activity caps the upwelling of material from below.
Sometimes a cap blows, and a visible flare results. The flares are loaded
with X-rays and other radiation, all of which reaches Earth moments after
the eruption and can be accompanied by a shower of protons.

These storms can arrive in moments with
little warning and can be deadly. Many flares are accompanied by clouds of
electrified gas called coronal mass ejections, which can slam Earth a day
or so later.

Earth is somewhat shielded from solar
storms, but some of the radiation leaks through our protective magnetic
field. Experts say space radiation is one of the biggest threats to
current and future space missions, including the effort to establish a
lunar base.

NASA.


Dave Reneke
News Editor