MOTHER'S DAY: Give your mom a truly heavenly gift on May 11th--a subscription to Space Weather PHONE! | | | SUPER SOLAR FLARE: In September 1859, the sun unleashed a solar flare so intense that the flash of light rivaled the surface brightness of the sun itself. A ferocious geomagnetic storm ensued in which Northern Lights descended as far south as the Bahamas and Hawaii. Meanwhile, telegraph engineers disconnected their batteries and powered communications by electricity from the auroras! Could it happen again? Get the answer from Science@NASA EARLY NOCTILUCENT CLOUDS: Just before daybreak on May 5th, experienced sky watchers in Northern Ireland were surprised by a sudden apparition of noctilucent clouds (NLCs). "I was outdoors looking for eta Aquarid meteors when I spotted an eerie glow between my neigbour's houses." reports Martin McKenna of Maghera, Co. Derry. "The strong blue color was unmistakable--it was an NLC." He took this picture at 4 a.m. local time: Noctilucent clouds are mainly a summertime phenomenon and it is very unusual for them to appear so early in May. "In my long years of observing NLCs, this is the earliest I have ever seen them," says John C McConnell who photographed the same May 5th display from Maghaberry, Northern Ireland: image. These sightings only add to the mystery of NLCs. High-latitude "night-shining clouds" were first reported in the 19th century after the eruption of super-volcano Krakatoa. At the time, the clouds were widely thought to be associated with the volcano. Long after the ash settled, however, NLCs persisted. In recent years they have intensified and spread with sightings as far south as Utah and Colorado. What causes the phenomenon? A NASA spacecraft named AIM is orbiting Earth on a mission to find out. The early onset of NLCs could herald a spectacular season to come. Readers, browse our 2007 NLC Photo Gallery for observing tips. Noctilucent Cloud Photo Gallery ["Noctilucent Cloud"--the song] [NLC Basics] RANDOM METEOR: Last week in the Black Forest of Germany, Achim Schaller was testing his new Nikon D300 by attaching it to his backyard telescope and taking a few pictures of the Leo Triplet of galaxies. "When I looked over the images," he says, "I found one of them had caught a meteor in flight." There was no meteor shower in progress on April 29th when Schaller took the picture. So where did the meteor come from? Scroll down for the answer: It was a "sporadic" or random meteor. Every night, thousands of them flit across the sky mostly unseen because they are so dim. The one in Schaller's photo registered 10th magnitude, too faint by a factor of 40 to see with the human eye. (Note: Not all random meteors are faint. Standing under the stars on a dark, moonless night, you can count a few sporadics every hour plainly visible to the unaided eye. Most, however, require a telescope.) Random meteors come not from any particular comet or asteroid, but from a diffuse swarm of space dust that fills the inner solar system. "Every day Earth sweeps up about 22 metric tons of this material," says Bill Cooke of NASA's Meteoroid Environment Office. He estimates that "40% of that mass, or 8.8 metric tons, turns into meteors of 10th magnitude or brighter: graph." If those metric tons arrived in a single lump, the result would be a fantastic fireball in the sky and possibly a scattering of meteorites on the ground. Instead, the swept-up material arrives mainly as microscopic bits and pieces, producing a faint drizzle of year-round meteor activity. The meteoroid in Schaller's photo probably had a mass "of around 0.00005 grams," notes Cooke. Tiny, but beautiful! April 2008 Aurora Gallery [Aurora Alerts] [Night-sky Cameras] |