by APOD Robot » Sat Aug 28, 2010 4:02 am
Hole in the Sun
Explanation: This ominous, dark shape sprawling across the face of the Sun is a
coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively
from space since the 1960s in ultraviolet and
x-ray light, coronal holes are known to be the source of the high-speed
solar wind, atoms and electrons
which flow outward along the open
magnetic field lines. During periods of low activity, coronal holes typically cover regions just above the Sun's poles. But this extensive coronal hole dominated the Sun's northern hemisphere earlier this week, captured here in extreme ultraviolet light by cameras onboard the
Solar Dynamics Observatory. The solar wind streaming from this coronal hole triggered auroral displays
on planet Earth.
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[url=http://apod.nasa.gov/apod/ap100828.html][img]http://apod.nasa.gov/apod/calendar/S_100828.jpg[/img] [size=150]Hole in the Sun[/size][/url]
[b] Explanation: [/b] This ominous, dark shape sprawling across the face of the Sun is a [url=http://helios.gsfc.nasa.gov/chole.html]coronal hole[/url] -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively [url=http://vestige.lmsal.com/TRACE/POD/Sunscapes.html]from space[/url] since the 1960s in ultraviolet and [url=http://imagine.gsfc.nasa.gov/docs/science/know_l2/sun.html]x-ray light[/url], coronal holes are known to be the source of the high-speed [url=http://www.spaceweathercenter.org/living_with_a_star/06/06.html]solar wind[/url], atoms and electrons [url=http://www.astrobio.net/pressrelease/3269/streams-of-the-sun]which flow outward[/url] along the open [url=http://solar.physics.montana.edu/YPOP/Spotlight/Magnetic/]magnetic field lines[/url]. During periods of low activity, coronal holes typically cover regions just above the Sun's poles. But this extensive coronal hole dominated the Sun's northern hemisphere earlier this week, captured here in extreme ultraviolet light by cameras onboard the [url=http://sdo.gsfc.nasa.gov/]Solar Dynamics Observatory[/url]. The solar wind streaming from this coronal hole triggered auroral displays [url=http://www.spaceweather.com/submissions/large_image_popup.php?image_name=Kjetil-Skogli-KSBH10_7826_1282754369.jpg]on planet Earth[/url].
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