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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VOYAGER 1 HAS LEFT THE SOLAR SYSTEM: Researchers have long waited for one of the Voyager probes to leave the solar system. In a surprising turn of events, NASA announced on Thursday that Voyager 1 entered interstellar space a whole year ago. This event sets in motion a new era of exploration of the realm between the stars. Congratulations to the Voyager team! [full story]
ALL QUIET ALERT: With the Sun's disk almost completely devoid of sunspots, solar flare activity has come to a halt. Measurements by NOAA's GOES 15 satellite show that the sun's global x-ray emission, a key metric of solar activity, has flatlined:
The quiet is unlikely to break this weekend. NOAA forecasters estimate a scant 1% chance of M- or X-class solar flares during the next 24-48 hours.
The quiet spell is a bit strange because 2013 is supposed to be a year of solar maximum, with lots of flares and sunspots. Supporting this view are data from NASA-supported observatories which show that the sun's magnetic field is poised to flip--a long-held sign that Solar Max has arrived. Nevertheless, solar activity is low.
One possible explanation is that Solar Max is double-peaked and we are in the valley between peaks. If so, solar activity could surge again in late 2013-2014. No one can say for sure, though. Researchers have been studying sunspots for more than 400 years, and we still cannot predict the behavior of the solar cycle. Continued quiet or stormy space weather? Both are possible in the weeks and months ahead. Solar flare alerts: text, voice.
Realtime Space Weather Photo Gallery
ARCTIC AURORAS: A medium-speed (~450 km/s) stream of solar wind is gently buffeting Earth's magnetic field. The action of the solar wind has not sparked a geomagnetic storm, but it has been enough to ignite naked-eye auroras around the Arctic Circle. Pilot Brian Whittaker was flying 35,000 feet over Greenland last night when he saw this display out the cockpit window:
"The brightest 'star' in the image is Jupiter," points out Whittaker. "It was pretty cool."
More auroras are in the offing. Another, more effective solar wind stream is due to reach Earth on or about Sept. 16th. NOAA forecasters estimate a 45% chance of polar geomagnetic storms. Aurora alerts: text, voice.
Realtime Aurora Photo Gallery
Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]
Realtime Comet Photo Gallery
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, 2013 there were 1426 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 |