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Sunday, Aug. 19, 2012
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What's up in space | |
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SIGNIFICANT
SOLAR FLARE, NOT EARTH-DIRECTED:
A magnetic filament snaking over the sun's northeastern
limb erupted on August 18th (01:02 UT), producing
a significant M5.5-class
solar flare. Click to view a movie of the eruption
recorded by NASA's Solar Dynamics Observatory:
A coronal mass ejection (CME) flew
away from the blast site, but the cloud is not heading
for Earth. This eruption was not geoeffective.
The magnetic filament reformed, post-eruption,
and appears to be connected to an active sunspot
group on the farside of the sun. Although the sunspot
is hidden behind the limb, the Solar Dynamics Observatory
can see the sunspot's towering magnetic canopy flashing
and hurling plasma over the edge of the sun. Click
on the image to set the scene in motion:
A great way to see the hidden sunspot
is using NASA's 3D Sun app, which shows our star
as a 3-dimensional globe that you can spin and inspect
from any angle. Data for the app come from a fleet
of three spacecraft (SDO + STEREO) that surround
the sun. Download the
app and look around the globe for a hot spot
labeled 'farside AR.' (AR="active region")
Soon, the sun's rotation will turn
the sunspot from the farside to the Earthside of
the sun. A significant uptick in geoeffective solar
activity is possible in the days ahead. Solar
flare alerts: text,
phone.
RETURN
OF THE ARCTIC AURORAS: It has been
a while since sky watchers around the Arctic Circle
have enjoyed the Northern Lights. Auroras are hard
to see through the glare of the midnight sun. As
summer comes to an end, however, aurora season is
beginning again. On August 16th, B.Art Braafhart
spotted a splash of green over Salla in the Finnish
Lapland:
"Finally, after three nights
hunting for 'the green lights,' I made the first
catch of the new season," says Braafhart. "The
nice temperature (+12C) was accompanied by zooming
mosquitos around midnight. The apparition was brief,
the colors thin and light, but after an absence
of 4 months exciting again!" Aurora
alerts: text,
phone.
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