NOCTILUCENT CLOUD IMAGES: They're back. Daily images of noctilucent clouds (NLCs) from NASA's AIM spacecraft have been restored to Spaceweather.com. A 1-month interuption in the data stream was caused by an anomaly on the spacecraft in July. The latest images (look here) show an abundance of clouds inside the Arctic Circle--remarkable considering that NLC season is usually finished by mid-August. Thus continues a record-setting year for noctilucent clouds. Browse: NLC Photo Gallery.
RED SPRITES AND TROLLS: If you've been paying attention to space weather in recent years, you've probably heard of sprites--exotic forms of lightning that leap up from powerful thunderstorms, reaching toward the edge of space. Now let us introduce you to trolls. Trolls are sprite-like tadpoles of light that sometimes follow sprites into the upper reaches of the atmosphere. On Aug. 12th, Martin Popek of Nýdek, Czechia, photographed these specimens:
"I captured them on two cameras," says Popek. "The leaped up from a big storm across the border in Poland."
Short for "Transient Red Optical Luminous Lineaments," trolls are occasionally observed alongside big clusters of sprites, and they can ascend 40 km to 60 km high. Why do they form? Sprites can actually pull Earth's ionosphere down toward the thunderstorm. When the gap shrinks, and the local electric field intensifies, trolls appear. It's another thing to look for above the clouds.
Realtime Sprite Photo Gallery
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DOUBLE DRONE-BOW: To see a rainbow, all you need are sunlight and falling rain. Correction: that's all you need to see half a rainbow. Typical rainbows are at least 50% hidden below the horizon. To see more, you also need a drone:
"After a rainstorm yesterday, I launched my drone," says Piotr Wieczorek of Opławiec, Poland. "As it ascended, an almost-full circle rainbow appeared. I took this picture using the onboard GoPro camera."
Rainbows always appear directly opposite the sun. As the drone rose above the physical horizon, the rainbow did, too. With only a little more lift, the circle would have been complete.
The drone view illustrates another common yet frequently overlooked aspect of rainbows. They are double. The interior or "primary rainbow" is caused by one reflection inside raindrops. The exterior or "secondary rainbow" is caused by two reflections. A double drone bow is a rare sight indeed.
Realtime Space Weather Photo Gallery
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APOLLO 11 PROOF SILVER DOLLARS: The students of Earth to Sky Calculus weren't even born when Neil Armstrong and Buzz Aldrin landed on the Moon in 1969 years ago. Nevertheless, they "get it." On July 20th, the students launched 50 Apollo 11 silver dollars to the stratosphere onboard a cosmic ray balloon. The coins touched the edge of space 50 years to the day after Neil and Buzz made footprints in the Sea of Tranquillity:
You can have one for $197.95. The students are selling these coins to support their cosmic ray ballooning program. Quantities are limited and more than half have already been sold. Each one comes with a greeting card showing the item in flight and telling the story of its journey to the edge of space.
Far Out Gifts: Earth to Sky Store
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