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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INCOMING CME: Another CME is en route to Earth. It was launched in our direction three days ago by the eruption of a magnetic filament near the center of the solar disk. The impact won't be as effective as the double-whammy of Sept. 12th, described below. Nevertheless, NOAA forecasters estimate a 40% chance of polar geomagnetic storms on Sept. 16th when the CME arrives. High-latitude sky watchers should remain alert for auroras. Aurora alerts: text, voice
AURORAS IN MOTION: As predicted, a pair of CMEs hit Earth's magnetic field in quick succession on Sept. 11th and 12th. The result was a G3-class geomagnetic storm, the most intense of the year so far. Around the Arctic Circle, "the storm sparked aurora displays that will never be forgotten by the people who were lucky enough to witness the event," reports tour guide Chad Blakley of Abisko, Sweden. "This short film is for everyone else."
At the peak of the storm, observers in Scandinavia witnessed stunning coronas and even a rare aurora-rainbow ensemble. A hint of auroras were even photographed in Arizona.
Another CME is en route to Earth. It was launched in our direction three days ago by the eruption of a magnetic filament near the center of the solar disk. The impact won't be as effective as the double-whammy of Sept. 12th. Nevertheless, NOAA forecasters estimate a 40% chance of polar geomagnetic storms on Sept. 16th when the cloud arrives. High-latitude sky watchers should remain alert for auroras. Aurora alerts: text, voice
Realtime Aurora Photo Gallery
SPACE WEATHER PROBE LAUNCHED: While the web site Spaceweather.com was down during the most intense geomagnetic storm of the year, the webmaster shook off the stress by going outside ... and launching a space weather probe. Carried aloft by a helium balloon, the probe was prepared and released by the students of Earth to Sky Calculus just as the planetary K-index hit 7during the waning hours of Sept. 12th:
Inside the balloon's payload, there was a high-energy radiation sensor, a cryogenic thermometer, multiple GPS altimeters and trackers, and three cameras to record the flight. The launch was the latest in an ongoing series of suborbital balloon flights to measure the effect of stormy space weather on Earth's atmosphere from ground level to the stratosphere. Soon, the group will release an entire year's worth of data of interest to commercial aviation and space tourism.
After a 2.5 hour flight, the payload has parachuted back to Earth and landed in the Inyo Mountains of central California. A student team will recover the payload and its sensors this weekend. Stay tuned.
Realtime Space Weather 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 Sep. 15, 2014, the network reported 16 fireballs.
(13 sporadics, 3 September epsilon Perseids)
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 September 15, 2014 there were 1500 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 |