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. | | |
NO METEOR OUTBURST? So far we have received no reports of a predicted gamma Delphinid meteor outburst on June 11th. If there was a stream of comet debris near Earth's orbit, either we missed it, or it was populated by meteoroids too small to produce naked-eye meteors. [Meteor radar]
AURORAS + NOCTILUCENT CLOUDS: On Sunday, June 9th, Alan Dyer of Gleichen, Alberta, Canada, went outside to see the colors of the sunset. He got more than he bargained for. Stacked atop the rosy glow of twilight were dual bands of electric-blue noctilucent clouds and green auroras:
"At times the auroral curtains appeared superimposed on the noctilucent clouds," says Dyer. "It isn't often we see the two phenomena together."
That's because they are completely unrelated. Auroras are caused by energetic particles from the sun raining down on Earth's upper atmosphere, causing the air to glow like the picture tube of a color TV. Noctilucent clouds are made of tiny ice crystals wrapped around bits of meteor smoke. Their electric-blue color comes from the scattering of high altitude sunlight. On June 9th the two phenomena overlapped for a rare display.
"Adding to the colours was the deep orange of perpetual twilight rimming the northern horizon," continues Dyer. "It was a beautiful pre-solstice night."
More aurora-noctilucent overlaps might be in the offing. NLC experts say noctilucent clouds have appeared bright and early this year, while 2013 might bring the late surge of a double-peaked Solar Max. High-latitude sky watchers should keep an eye on the sunset. Aurora alerts: text, voice.
Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]
WEIRD SUNSET: Astronomers in the Netherlands have discovered a world where the sun is square. It is Earth. On June 6th Jan Koeman was watching the sunset from Lauwersoog, and this is what he saw:
"The sunset was a very weird one," says Koeman. "Inversions in the atmosphere gave it some very odd shapes."
UK atmospheric optics expert Les Cowley was in the Netherlands last week. "Conditions were favorable for this kind of mirage," he says. "To see weird miraged suns look out at sunrise in very cold weather and at sunset when it is hot. We had beautiful hot sunny weather all last week in the Netherlands. The sun heated the land and topmost layers of the sea to generate by early evening strong temperature inversions, layers of unusually warm air beneath cooler air. The setting sun rays slanted through the layers where they were bent to form multiple image slices that combine into outlandish shapes and even stacked pancakes. Sometimes tiny green flashes can be photographed on the topmost pancake."
"I was looking for the green flash," adds Koeman, "but this time no success. More sunsets will follow."
Realtime Space Weather Photo Gallery
Realtime Aurora Photo Gallery
Realtime Comet Photo Gallery