iPHONE VS ANDROID! Actually, it doesn't matter which phone you carry. Our cool, new app turns both smartphones into field-tested satellite trackers. Learn more.
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NASA MISSION TO TOUCH THE SUN: NASA's daring plan to visit the sun took a giant leap forward today with the selection of five key science investigations for the Solar Probe+ spacecraft. Get the full story from Science@NASA.
BLOWING BUBBLES: Emerging sunspot 1105 erupted today at 1520 UT, producing a B2-class solar flare. The minor blast blew a bubble in the sun's atmosphere more than 50,000 km wide. The action unfolds in this extreme ultraviolet movie from the Solar Dynamics Observatory:
Watch it again. The bubble is the dark crescent-shaped void expanding to the upper left of the sunspot's bright magnetic canopy. Several copies of our entire planet Earth could fit inside that volume with room to spare. What seems huge by Earth-standards, however, is miniscule on the sun. At maximum, the bubble occupied a volume less than 0.003% of the total solar globe. It's all relative, after all.
Stay tuned for bigger bubbles as sunspot 1105 continues to grow.
VIRTUAL REALITY PARHELIC CIRCLE: A parhelic circle is an unforgettable sight. Thin and pale, it circles the zenith in a majestic arc, always keeping the same distance above the horizon. "I've been looking for a parhelic circle for more than 13 years," says photographer Laurent Laveder of Pluguffan, France. "Yesterday I finally saw one." He rushed for his camera and quickly snapped enough pictures to assemble a complete 360o zenith-to-horizon composite view of the phenomenon. Click on the image below to experience the VR parhelic circle:
Parhelic circles are caused by sunlight reflecting from the vertical faces of ice crystals--millions of them floating in thin cirrus clouds spread almost evenly across the wide blue sky. As Les Cowley notes in his authoritative web page on the subject, "the parhelic circle appears simple yet more ray paths contribute to it than in any other halo. Some are very intricate."
A striking aspect of the parhelic circle is its dual personality. At the same time it appears both circular and straight. "These two pictures (1, 2) illustrate the effect," says Laveder. More images may be found here.
August 2010 Northern Lights Gallery
[previous Augusts: 2009, 2008, 2007, 2006, 2005, 2004, 2003]