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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A MARS ROVER'S IMPROBABLE ANNIVERSARY: When Opportunity left Earth on July 7, 2003, many observers expected the rover to survive no more than a few months on the hostile surface of Mars. Ten years later, Opportunity is still going strong and could be poised to make its biggest discoveries yet at a place named Solander Point. [video] [full story]
SHAPE-SHIFTING SUNSPOT: Behemoth sunspot AR1785 is undergoing a metamorphasis, changing shape by the hour as it turns toward Earth. This movie from NASA's Solar Dynamics Observatory shows the action on July 6-7:
In less than 24 hours, AR1785 has stretched and lengthened by more than 40,000 km. It is now more than 11 times as wide as Earth, which makes the active region an easy target for backyard solar telescopes.
One thing hasn't changed: the sprawling sunspot group has a 'beta-gamma-delta' magnetic field that harbors energy for strong solar flares. Moreover, the shape-shifting of AR1785 could lead to explosive instabilities in the sunspot's magnetic canopy. NOAA forecasters estimate a 55% chance of M-class solar flares and a 10% chance of X-flares during the next 24 hours. Solar flare alerts: text, voice.
Realtime Space Weather Photo Gallery
WEEKEND AURORAS: Auroras are a sign of geomagnetic storms. Sometimes they are a sign of no geomagnetic storms, too. On July 5-6, observers in Canada and upper-tier US states spotted auroras even though no storm was in progress. John Vose sends this picture from Lake Willoughby in northern Vermont:
"The clouds were lit by occasional lightning, and the rocks were illuminated with my cell phone," says Vose. It was a lucky shot because "soon after the auroras appeared, the fog rolled in...."
At the time, Earth was passing through a region of interplanetary space with a south-pointing magnetic field. The encounter opened a crack in Earth's magnetosphere; solar wind poured in to fuel the auroras. Despite the colorful lights, geomagnetic activity never crossed the threshold into full-fledged storming.
Actual storms could be in the offing, however. A solar wind stream is approaching Earth, due to arrive on July 7-8. NOAA forecasters estimate a 30% to 35% chance of polar geomagnetic storms. 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!
Realtime Space Weather Photo Gallery
Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]
Realtime Comet Photo Gallery