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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.
Researchers including Prof. Peter
Brown of the University of Western Ontario along
with NASA experts 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 15 meters in
diameter and weighed approximately 7000 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 300 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 today'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."
Stay tuned for updates!
GOOD-BYE 2012 DA14:
Asteroid 2012
DA14 few past Earth on Feb. 15th inside the
orbit of many geosynchronous satellites. At closest
approach, around 2:25 pm EST, the 45-meter wide
space rock was only 17,200 miles above Indonesia.
No satellites were damaged by the flyby, and the
asteroid is now receding from Earth.
Using a 3" refractor at the Siding
Spring Observatory in Australia, Aaron Kingery captured
this image of 2012 DA14 passing in front of the
eta Carina Nebula:
NASA's Goldstone radar in the Mojave
Desert will ping the space rock for the next four
days to refine its orbit and map its surface features.
Researchers will look carefully for signs that Earth's
gravity might have caused seismic
activity on the asteroid.
Browse the realtime
gallery for more images from around the world.
Realtime
Space Weather Photo Gallery
VALENTINE'S DAY MAGNETIC
STORM: Valentine's Day in Scandinavia
began with a magnetic storm. Rob Stammes of the
Polar Light Center in Lofoten, Norway, reports:
"Our instruments recorded 2o swings
in the local magnetic field, which induced strong
electrical currents in the ground outside our lab."
The needles on his chart recorder were swinging
wildly:
"Overhead we saw some fantastic
auroras," he adds.
The storm was caused by a region of
south-pointing magnetism in the solar wind that
wafted past Earth during the early hours of Feb.
14th. The solar wind's south-pointing magnetic field
partially canceled Earth's north-pointing magnetic
field, opening a crack in our planet's magnetosphere.
Solar wind poured in to fuel the storm.
Browse the realtime
gallery for images of some sweet auroras on
Valentine's day.
Aurora alerts:
text,
voice.
Realtime
Aurora Photo Gallery
Realtime
Comet Photo Gallery
Realtime
Noctilucent Cloud Photo Gallery
[previous years: 2003,
2004,
2005,
2006,
2007,
2008,
2009,
2011]
