Forecasts of solar flares and geomagnetic storms, plus daily animations of the sun.
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VERY QUIET SUN: Solar
activity has returned to very low levels, and it is likely to remain so
for the next few days. NOAA forecasters say there is no more than a 1%
chance of strong flares on March 25-26-27. Solar flare alerts: text or voice
RADAR IMAGES OF EARTH-BUZZING COMET: On
March 22nd, comet fragment P/2016 BA14 made the 3rd-closest approach to
Earth of any comet in recorded history. NASA researchers took advantage
of the comet's proximity and pinged its icy core using the Goldstone
Solar System Radar in California's Mojave Desert. Newly released images
reveal a 1-km wide strangely-shaped object spinning once every 35 to 40
hours:
"The comet has an irregular
shape. It looks like a brick on one side and a pear on the other,"
says Shantanu Naidu, a postdoctoral researcher at NASA's Jet Propulsion
Laboratory who led the observations. "We can see quite a few
signatures related to topographic features such as large flat regions,
small concavities and ridges on the surface of the nucleus."
While the radar observations
were underway, Vishnu Reddy of the Planetary Science Institute in
Tucson, Arizona, also observed P/2016 BA14 using the Infrared
Telescope Facility on Mauna Kea, Hawaii. He found that the comet
reflects less than 3 percent of the sunlight that falls on its
surface. In other words, it was as dark as fresh asphalt.
CORONAL CANYON SPEWS SOLAR WIND: A
gaseous canyon has opened up in the sun's atmosphere, and it is spewing
solar wind toward Earth. NASA's Solar Dynamics Observatory is
monitoring the structure, shown here in an extreme ultraviolet image
taken on March 25th:
This is a canyon-shaped
example of a coronal hole--a place in the sun's atmosphere where the
magnetic field spreads apart and allows solar wind to escape. In the
image, above, the coronal hole is colored deep-blue, while the flow of
solar wind is indicted by white arrows.
A stream of solar wind
flowing from the canyon should reach Earth on March 28th. There's a good
chance its arrival will bring auroras. The reason is, the stream will
be preceded by a co-rotating interaction region or "CIR." CIRs are
transition zones between slow- and
fast-moving solar wind streams. Solar
wind plasma piles up in these regions, producing
density gradients and shock waves that do a
good job of sparking Northern
Lights. Aurora alerts: text or voice
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