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Noctilucent clouds — the rarest clouds in the world — glowed like shimmering cobwebs in the sky over the San Francisco Bay Area early Friday morning, and experts think they were likely the result of a rocket launch. Skywatchers across the region were delighted by the otherworldly spectacle overhead and shared images on social media. One Twitter user posted a photo taken in the Sunset District at 6:30 a.m. "Pretty crazy looking," the tweet read. Scientists chimed in with excitement. "Great shot of what appears to be a noctilucent cloud over the SF Bay Area this morning!" UCLA climate scientist...

Over the next few weeks, mid-latitude observers might experience the best noctilucent cloud viewing of their lifetimes. Observers over the northern half of the U.S. are reporting something they have never seen before — electric-blue noctilucent (night-shining) clouds. They are wispy in appearance, and continuously change shape. They can be seen when the sun is about 6 to 16 deg. below the horizon, so about 1 to 2 hours after sunset or before sunrise. During that time of night the sun is still shining on these clouds, but not on any normal weather-related clouds. In the late spring every year,...

NASA’s AIM spacecraft is monitoring a vast ring of electric-blue clouds circling high above Antarctica. These are noctilucent clouds (NLCs), made of ice crystals frosting specks of “meteor smoke” in the mesosphere 83 km above the frozen continent. Here is an animation from the past week: This is the season for southern noctilucent clouds. Every year around this time, summertime water vapor billows up into the high atmosphere over Antarctica, providing moisture needed to form icy clouds at the edge of space. Sunlight shining through the high clouds produces an electric-blue glow, which AIM can observe from Earth orbit. “The...

ELECTRIC-BLUE CLOUDS CIRCLING ANTARCTICA: NASA's AIM spacecraft is monitoring a vast ring of electric-blue clouds circling high above Antarctica. These are noctilucent clouds (NLCs), made of ice crystals frosting specks of "meteor smoke" in the mesosphere 83 km above the frozen continent. This is the season for southern noctilucent clouds. Every year around this time, summertime water vapor billows up into the high atmosphere over Antarctica, providing moisture needed to form icy clouds at the edge of space. Sunlight shining through the high clouds produces an electric-blue glow, which AIM can observe from Earth orbit. "The current season began on...

The southern season for noctilucent clouds (NLCs) has come to an end. NASA's AIM spacecraft observed the last wisps of electric-blue over Antarctica on Feb. 20, 2015. The end of the season was no surprise: The polar clouds always subside in late summer. Looking back over the entire season, however, reveals something unexpected. In an 8-year plot of Antarctic noctilucent cloud frequencies, the 2014-2015 season is clearly different from the rest: These data come from the AIM spacecraft, which was launched in 2007 to monitor NLCs from Earth orbit. The curves show the abundance ("frequency") of the clouds vs. time...

After the sun sets on a summer evening and the sky fades to black, you may be lucky enough to see thin, wavy clouds illuminating the night, such as these seen over Billund, Denmark, on July 15, 2010. Clouds bright enough to see at night are not as hard to find as they once were. These so-called night-shining clouds are still rare — rare enough that Matthew DeLand, who has been studying them for 11 years, has seen them only once. But his odds are increasing. [Related: In Images: Reading the Clouds.] These mysterious clouds form between 50 and...

Mysterious glowing clouds targeted by NASA 17:07 26 May 2006 NewScientist.com news service Maggie McKee Print this pageEmail to a friendRSS Feed High-altitude noctilucent clouds have been mysteriously spreading around the world in recent years (Image: NASA/JSC/ES and IA) AIM mission, Hampton University Noctilucent clouds, University of Colorado Scott Bailey, University of Alaska Glowing, silvery blue clouds that have been spreading around the world and brightening mysteriously in recent years will soon be studied in unprecedented detail by a NASA spacecraft. The Aeronomy of Ice in the Mesosphere (AIM) mission will be the first satellite dedicated to studying this enigmatic...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 June 15 Noctilucent Clouds Credit & Copyright: Pekka Parviainen (Polar Image) Explanation: Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above. Under usual circumstances, a pretty sunset might be visible, but unusual noctilucent clouds float so high up they...

<p>SAN JOSE, Calif.(AP) - The space shuttle Columbia broke up in a mysterious area of the upper atmosphere once so little understood and difficult to study that scientists dubbed it the "ignorosphere."</p> <p>On Friday, NASA said it has asked outside atmospheric scientists for their opinion on whether some sort of electrical discharge could have occurred as the shuttle screamed toward touchdown at Kennedy Space Center in Florida.</p>