When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms.
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THE ALL QUIET EVENT: The "All Quiet Event" is still underway. For the 6th day in a row, solar activity is extremely low, with weak solar wind, no flares, and a sunspot number near zero. NOAA forecasters put the odds of a significant flare today at no more than 1%. Follow the action, or lack thereof, on Twitter @spaceweatherman.
RED SPRITES OVER NEW MEXICO: Solar activity is extremely low. Nevertheless, space weather continues. High above thunderstorms in the American west, red sprites are dancing across the cloudtops, reaching up to the edge of space itself. Harald Edens photographed this specimen on July 18th from the Langmuir Laboratory for Atmospheric Research in New Mexico:
"This colorful sprite occurred over a large thunderstorm system in northeast New Mexico and was visible to the naked eye," says Edens. "I took the picture using a Nikon D4s and a 50 mm f/2 lens at ISO 25600."
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!
Realtime Sprite Photo Gallery
FARSIDE CME: During the early hours of July 20th, a coronal mass ejection (CME) exploded from the far side of the sun. SOHO recorded the cloud as it billowed over the sun's northeastern limb:
Although the CME appears to envelop Jupiter, it does not. Jupiter is almost 500 million miles behind the sun. The apparent intersection is just the CME passing in front of the giant planet.
Images taken by NASA's STEREO-B probe, which is stationed over the farside of the sun, suggest that the CME was propelled into space by an erupting filament of magnetism possibly connected to a small sunspot. We will get a direct view of the blast site in a few days when it rotates onto the Earthside of the sun. Overall, solar activity remains low despite this relatively minor outburst.
Realtime Space Weather Photo Gallery
Realtime NLC Photo Gallery
Realtime Comet Photo Gallery
Realtime Aurora 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 Jul. 21, 2014, the network reported 4 fireballs.
( 4 sporadics)
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 July 21, 2014 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 |