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. | | |
WEAK IMPACT: A minor CME hit Earth's magnetic field on July 9th at approximately 20:30 UT. The impact was weak and did not immediately trigger a geomagnetic storm. Aurora alerts: text, voice.
POTENT SUNSPOTS, STILL QUIET: Sunspots AR1785 and AR1787 are defying the odds. Despite the fact that both sunspots have unstable magnetic fields laden with energy for strong flares, solar activity remains low. Maybe it is the calm before the storm. NOAA forecasters estimate a 55% chance of M-class solar flares on July 8th. Solar flare alerts: text, voice.
THE THINNEST CRESCENT: Astrophotographer Thierry Legault is known for his razor-sharp images of spacecraft. Yesterday, for a change of pace, he photographed a razor-sharp crescent:
"This image shows the tiny lunar crescent at the precise moment of the New Moon, in full daylight at 7h14min UTC on July 8 2013," says Legault. "It is the youngest possible crescent, the age of the Moon at this instant being exactly zero."
"From the shooting site in Elancourt, France, the angular separation between the Moon and the Sun was only 4.4° (nine solar diameters)," he continues. "At this very small separation, the crescent is extremely thin (a few arc seconds at maximum) and, above all, it is drowned in the solar glare, the blue sky being about 400 times brighter than the crescent itself in infrared and probably more than 1000 times brighter in visible light. In order to reduce the glare, the images have been taken at near-infrared wavelengths using a pierced screen placed just in front of the telescope to block direct sunlight."
Legault's photo may have theological as well as astronomical significance. In the Muslim world, the New Moon of July 8th and the sighting of the first crescent afterward sets the stage for the beginning of Ramadan 2013.
Realtime Space Weather Photo Gallery
SOUTHERN LIGHTS: On July 6-7, Earth passed through a region of interplanetary space with a south-pointing magnetic field. The encounter opened a crack in Earth's magnetosphere, allowing solar wind to flow inside. The resulting auroras were best seen in the wintry-dark skies of the southern hemisphere:
"These were the biggest auroras so far this year," says photographer Taichi Nakamura of Dunedin, New Zealand. "I rushed my 2 year old son and wife to finish their dinner, and I am glad I did. They enjoyed the show! It helped that the night was warmer than usual, not going under 0 degrees Celsius. I myself became so excited that I took more than 2500 shots."
More auroras could be in the offing. A slow-moving CME expelled from the sun on July 6th is expected to hit Earth's magnetic field on July 10th. Minor geomagnetic storms are possible when the CME arrives. Aurora alerts: text, voice.
Realtime Aurora Photo Gallery
SPACE WEATHER BALLOON CLIFFHANGER: On July 2nd a recovery team reached the payload of a space weather balloon launched on June 30th. It was the second attempt to retrieve the balloon from its mountainous landing site in the Sierra Nevada mountains of central California. The first attempt late on July 1st was aborted due to challenging terrain and fading sunlight. This time, the team started earlier and in the full light of midday they found the landing site. It turned out to be a cliffhanger:
As shown above, the payload was dangling from a shear cliff face more than 1400 feet above the foot of the Nevahbe Ridge. Super-climber Michael White, a member of the Earth to Sky Calculus student group that launched the balloon, was able to reach the landing site and snag the payload from the safety of a small ledge just above the parachute. The shoe in the photo belongs to Michael.
This balloon was launched at the peak of a record-setting heat wave in the southwestern USA, bringing temperatures as high as 128 F to desert areas around the launch site. The goal of the curiosity-driven flight was to discover whether the heat wave extended all the up to the Edge of Space. To help answer the question, the balloon's payload was outfitted with two HD video cameras, a pair of GPS trackers, a GPS altimeter, a cryogenic thermometer and an ozone sensor.
Students are analyzing the footage and data now. Stay tuned for results!
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