Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift. |
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JUPITER AND THE MOON:
When the sun goes down tonight,
step outside and look south. The Moon is passing
Jupiter in the constellation Taurus. It's a pretty
close encounter visible even through city lights.
[sky map]
[photos]
COMET PAN-STARRS
UPDATE: Comet Pan-STARRS (C/2011
L4), widely expected to become a naked-eye object
in early March, is now closer to the sun than Venus.
Solar heating is vaporizing the comet's icy core
and creating a wide, fan-shaped tail visible through
binoculars in the southern hemisphere. Ignacio Diaz
Bobillo sends this picture from Buenos Aires, Argentina:
"I saw Comet Pan-STARRS just
before daybreak in the constellation Grus,"
says Bobillo. "This is what it looked like
through a small telescope, imaged with an exposure
time of 8x2 minutes."
In early March, Comet Pan-STARRS
will make its closest approach to the sun inside
the orbit of Mercury; at that time it could brighten
to easy naked-eye visibility. No one knows exactly
what will happen, however, because it is a fresh
comet being exposed to solar heating for the first
time. Experts discuss the possibilities in this
video from Science@NASA. More:
3D
orbit, ephemeris,
light
curves, NASA
story.
Realtime
Comet Photo Gallery
M-CLASS SOLAR FLARE:
Yesterday, Feb. 17th, new sunspot
AR1675 unleashed the most intense flare of the year
so far, an M1.9-class
explosion. NASA's Solar Dynamics Observatory captured
a double-flash of extreme UV radiation from the
explosion:
Coronagraph images from SOHO and the
twin STEREO probes show that this explosion did
not produce a coronal mass ejection (CME). Nevertheless,
there were some Earth-effects. UV radiation from
the flare produced a wave of ionization in Earth's
upper atmosphere. Radio listeners in Europe
and North
America detected the sudden ionospheric disturbance.
Solar flare alerts: text,
voice.
Realtime
Space Weather Photo Gallery
RUSSIAN METEOR UPDATE:
On Friday, February 15th at 9:30
am local time in Russia, a small asteroid struck
the atmosphere over the city of Chelyabinsk and
exploded. According to reports from news organizations
and Russian authorities, as many as 1000 people
received minor injuries from the shock wave. This
is the most energetic recorded meteor strike since
the Tunguska impact of 1908.
Note: In the following
paragraph, bold-faced numbers were updated on Feb.
17th to reflect new and improved estimates of the
asteroid's size and energy. It was even bigger than
we thought!
Researchers have conducted a preliminary
analysis of the event. "Here is what we know
so far," says Bill Cooke, head of NASA's Meteoroid
Environment Office. "The asteroid was about
17 meters in diameter and weighed
approximately 10,000 metric tons.
It struck Earth's atmosphere at 40,000 mph (18 km/s)
and broke apart about 12 to 15 miles (20 to 25 km)
above Earth's surface. The energy of the resulting
explosion was in the vicinity of 500 kilotons
of TNT." (continued below)
"A shock wave propagated down
and struck the city below, causing large numbers
of windows to break, some walls to collapse, and
minor damage throughout the city," he continued.
"When you hear about injuries, those are undoubtedly
due to the effects of the shock wave, not due to
fragments striking the ground. There are undoubtedly
fragments on the ground, but as of this time we
know of no recovered fragments that we can verify."
Videos of the event may be found here
and here.
In many of the videos you can hear the sound of
windows shattering as the meteor's loud shock wave
reaches the ground. Onlookers cry out in Russian
as alarms and sirens sound in the background. This
pair of wide-angle gif animations is also worth
watching: #1,
#2.
It is natural to wonder if this event
has any connection to Friday's record-setting
flyby of asteroid 2012 DA14. Paul Chodas of
the Near Earth Object Program at JPL says no. "The
Russian fireball is not related to 2012 DA14 in
any way. It's an incredible coincidence that we
have had these two rare events in one day."
Realtime
Asteroid Photo Gallery
Realtime
Aurora Photo Gallery
Realtime
Noctilucent Cloud Photo Gallery
[previous years: 2003,
2004,
2005,
2006,
2007,
2008,
2009,
2011]
