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LYRID METEOR SHOWER: Earth is approaching the debris field of ancient Comet Thatcher, source of the annual Lyrid meteor shower. Forecasters expect the shower to peak on April 21-22; a nearly-new moon on those dates will provide perfect dark-sky conditions for meteor watching. Usually the shower is mild (10-20 meteors per hour) but unmapped filaments of dust in the comet's tail sometimes trigger outbursts 10 times stronger. [video] [Lyrid chat] [more]
NO CME, NO PROBLEM: A CME expected to hit Earth on April 9th missed, but the Arctic lit up with auroras anyway. Yuichi Takasaka sends this report from the Northwest Territories of Canada: "Even though the CME missed, we had three outbreaks of Northern Lights at Prelude Lake." Here is one of them:
The source of the display was the IMF (interplanetary magnetic field), which tipped south on April 9th, opening a crack in Earth's magnetosphere. Solar wind poured in and fueled the auroras.
More Arctic lights are possible on April 13-14 when a high speed solar wind stream is expected to hit Earth's magnetic field. NOAA forecasters estimate a 20% chance of geomagnetic storms around the poles. Aurora alerts: text, phone.
more images: from Frank Olsen of Blokken in Sortland, Norway; from Ole C. Salomonsen of Tromsø, Norway; from Anne Fyhn of Grøtfjord, Tromsø, Norway; from Harald Albrigtsen of Grøtfjorden, Norway; from Sylvain Serre of Ivujivik, Nunavik, Quebec, Canada; from Göran Strand of Rörvattnet, Sweden;
SEVEN ICE HALOES: As spring unfolds, Arctic daylight will soon wrap all the way around the clock, chasing away midnight displays of aurora borealis. There are compensations, however, for 24-hour sunlight. It increases the odds of witnessing ice haloes around the sun. On April 4th, Fredrik Broms photographed this display over Rovaniemi, Finland
"Looking up at the sky during daytime can be rewarding," says Broms. "In the cold crisp air in Finland a beautiful ice halo display was visible a few days ago."
The luminous rays, rings, and arcs he photographed are caused by sunlight shining through ice crystals in the air. Looking carefully, Broms counted at least seven distinct ice halos around the sun: labeled image.
You don't have to be in the Arctic to witness displays like this. Temperatures are freezing all around the world in clouds ~10km above the ground. Sunlight shining through icy clouds can produce haloes anywhere. Browse the links for more examples: from Ivo Dinsbergs of Riga, Latvia; from Heiko Ulbricht of Freital, Saxony, Germany.