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VERY QUIET SUN: With no sunspots actively flaring, the sun's X-ray output has flatlined. Solar activity is very low and likely to remain so for the next 24 hours. According to NOAA forecasters, the chance of a strong flare on May 26th is no more than 1%. Solar flare alerts: text, voice
SPRITES OVER OKLAHOMA: On Saturday night, May 23rd, strong thunderstorms raked Texas and Oklahoma, producing torrential rains and deadly floods. Amateur astronomer Thomas Ashcraft could see the lightning bolts all the way from New Mexico--and not all of them were going down. "There was a bright display of sprites shooting up from the tops of the thunderclouds," says Ashcraft. He took this picture using a near-infrared camera at his observatory outside Santa Fe:
Sprites are an exotic form of lightning that appear very high above Earth's surface, at the edge of space itself.
"Sprites are a true space weather phenomenon," says lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain. "They develop in mid-air around 80 km altitude, growing in both directions, first down, then up. This happens when a fierce lightning bolt draws lots of charge from a cloud near Earth's surface. Electric fields [shoot] to the top of Earth's atmosphere--and the result is a sprite."
How exotic are they? This close-up view of the Oklahoma sprites says it all:
"Turn up the volume," advises Ashcraft. "In the movie you can hear the very low frequency radio crackles from individual lightning strokes."
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" routinely photograph sprites from their own homes. Give it a try.
Realtime Sprite Photo Gallery
POLLEN CORONAS: It begins with a sneeze. Pollen floating through the air tickles your nose, and your body responds by expelling the allergen. Gesundheit! When the paroxysm subsides, look up at the sky. The same pollen that makes you sneeze can also make beautiful coronas around the sun, like this one photographed on May 24th by Peter Paul Hattinga Verschure of Deventer, the Netherlands:
"Springtime pollen was drifting through the air of Deventer," says Verschure. "Hiding the sun behind a lamp post revealed this corona no more than 3 degrees wide." Sharpening the image uncovers an even wider network of colorful rings: click here.
Atmospheric optics expert Les Cowley explains the phenonenon: "Coronas are produced when light waves scatter from the outsides of small particles. Tiny droplets of water in clouds make most coronas, but opaque equal-sized pollen grains do even better. They make small but very colorful multi-ringed coronas."
"Unlike water droplets, pollens are non-spherical--and this adds to their magic," he continues. "Many have air sacs to help carry them in the wind. These align the grains to give beautiful elliptical coronas with bright spots." This is why Verschure's pollen corona looks the way it does.
As northern spring unfolds, pollen coronas become increasingly common. Look for them the next time your nose feels a tickle.
Realtime Space Weather Photo Gallery
Realtime Aurora Photo Gallery
Realtime Comet Photo Gallery
Every night, a network of NASA 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 May. 26, 2015, the network reported 7 fireballs.
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 ones
all the time.
On May 26, 2015 there were 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.
| ||The official U.S. government space weather bureau |
| ||The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| ||Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| ||3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| ||Realtime and archival images of the Sun from SOHO. |
| ||from the NOAA Space Environment Center |
| ||the underlying science of space weather |