They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store. |
|
|
X-FLARE!
Big sunspot AR1520 unleashed an
X1.4-class solar flare on July 12th at 1653 UT.
Because this sunspot is directly facing Earth, everything
about the blast was geoeffective. For one thing,
it hurled a coronal mass ejection (CME) directly
toward our planet. According to a forecast
track prepared by analysts at the Goddard Space
Weather Lab, the CME will hit Earth on July 14th
around 10:20 UT (+/- 7 hours) and could spark strong
geomagnetic storms. Sky watchers should be alert
for auroras this weekend. Geomagnetic
storm alerts: text,
voice.
The explosion also strobed Earth with
a pulse of extreme UV radiation, shown here in an
image captured by NASA's Solar Dynamics Observatory:
The UV pulse partially ionized Earth's
upper atmosphere, disturbing the normal propagation
of radio signals around the planet. Monitoring stations
in
Norway and
Ireland recorded the sudden ionospheric disturbance.
Finally, solar protons accelerated
by the blast are swarming around Earth. The radiation
storm, in
progress, ranks "S1" on NOAA space
weather scales, which means it poses no serious
threat to satellites or astronauts. This could change
if the storm continues to intensify. Stay tuned.
Realtime
Space Weather Photo Gallery
NOCTILUCENT
CLOUDS: This morning a vast bank
of electric-blue noctilucent clouds rippled across
northern Europe. "It was like water in the
sky," says Barbara Grudzinska, who photographed
the display from Warsaw, Poland:
"These are the first noctilucent
clouds this year so clearly visible at our latitude
in Warsaw (52 N)," says Grudzinska.
When NLCs first appeared in the 19th
century, the mysterious
clouds were confined to the Arctic, most often
seen in the same places as Northern Lights. In recent
years, however, their "habitat" has been
expanding, rippling as far south as Colorado, Virginia,
Kansas, and Utah. (Here
are
some
examples
of sightings in the lower United States.) There
is growing evidence that the expansion is a sign
of climate change, although this remains controversial.
Whatever the reason, noctilucent clouds aren't
just at high latitudes anymore, so sky watchers
everywhere should be alert for them. Observing
tips: Look west 30 to 60 minutes after
sunset when the sun has dipped 6o
to 16o below the horizon. If you see
luminous blue-white tendrils spreading across the
sky, you've probably spotted a noctilucent cloud.
Realtime
Noctilucent Cloud Photo Gallery
[previous years: 2003,
2004,
2005, 2006,
2007, 2008,
2009,
2011]
SOLAR
ARCHIPELAGO: Sunspots are magnetic
islands on the sun. Sunspot AR1520 is a complete
archipelago. Scroll down to scan more than 200,000
miles of island chain:
Amateur astronomer Alan
Friedman took the picture on July 10th from
his backyard observatory in Buffalo, New York. "AR1520
is a tremendous archipelago and a wonderful target
for backyard solar
telescopes," he says.
The tangled magnetic canopy of the
sunspot group, shown
here in an extreme UV image from NASA's Solar
Dynamics Observatory, harbors energy for strong
solar flares. NOAA forecasters estimate an 80% chance
of M-class flares and a 15% chance of X-class flares
during the next 24 hours.
Solar flare alerts: text,
voice.
Realtime
Sunspot Photo Gallery
Realtime
Space Weather Photo Gallery
Realtime
Planets Photo Gallery
[NASA video: A
Good Reason to Wake Up at Dawn]
