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GROUND CURRENTS IN NORWAY: A weak CME expected to hit Earth's magnetic field on Nov. 20th did not reveal itself as an obvious disturbance in the speed of the solar wind. Nevertheless, it might have been there. A surge in ground currents in northern Norway suggests a stealthy CME impact might have occured, after all. Aurora alerts: text, voice
RED SPRITES OVER THE ADRIATIC: Summer is the season for sprites, a form of lightning that leaps up from the tops of thunderstorms. This picture, just in from Dubrovnik, a Croatian city on the Adriatic Sea, shows that they can be seen in autumn, too:
"I was photographing a distant thunderstorm when this red sprite appeared," says Boris Basic of Dubrovnik. "It is a rare upper atmospheric phenomenon."
Inhabiting the upper reaches of Earth's atmosphere alongside noctilucent clouds, meteors, and some auroras, sprites are a true space weather phenomenon. Some researchers believe they are linked to cosmic rays: subatomic particles from deep space striking the top of Earth's atmosphere produce secondary electrons that, in turn, could provide the spark that triggers sprites.
Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now "sprite chasers" regularly photograph the upward bolts from their own homes. Give it a try!
Space Weather Photo Gallery
SUB-SUNDOG: Next week's Thanksgiving is the biggest travel holiday of the year in the United States. Millions of people board airplanes and fly long hours to visit friends and family. Dreading the trip? Think of it as a sky watching opportunity. There are some things you can see only through the window of an airplane--like this:
"In the tops of the clouds, I saw a bright reflection of the sun flanked by rainbow-colored sundogs," says Alex Ruege, who snapped the picture on November 14th while he was flying over Phoenix, Arizona.
Atmospheric optics expert Les Cowley explains the apparition: "Look down from the sunny side of an aircraft and you will often see a dazzling reflection of the sun in the clouds. This is a subsun, formed by millions of plate shaped ice crystals acting as mirrors. Sometimes the subsun is flanked by two colorful sub-sundogs. How do they form? Sunlight nearly always bounces up and down inside the thin ice plates before it can emerge. An even number of bounces make a sundog. An odd number makes the sub-sundog. When you see halos always check out the opposite direction – you might see even rarer sights!"
Space Weather Photo Gallery
Comet Photo Gallery
Aurora Photo Gallery
Every night, a network
all-sky cameras scans the skies above the United
States for meteoritic fireballs. Automated software
maintained by NASA's Meteoroid Environment Office
calculates their orbits, velocity, penetration depth
in Earth's atmosphere and many other characteristics.
Daily results are presented here on Spaceweather.com.
On Nov. 21, 2014, the network reported 37 fireballs.
(21 sporadics, 10 Leonids, 2 alpha Monocerotids, 2 Northern Taurids, 2 November omega Orionids)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]
Potentially Hazardous Asteroids (PHAs
are space rocks larger than approximately 100m that
can come closer to Earth than 0.05 AU. None of the
known PHAs is on a collision course with our planet,
although astronomers are finding new
all the time.
November 21, 2014 there were 1513
potentially hazardous asteroids.
Notes: LD means
"Lunar Distance." 1 LD = 384,401 km, the distance
between Earth and the Moon. 1 LD also equals 0.00256
AU. MAG is the visual magnitude of the asteroid on
the date of closest approach.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO
is the most advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather