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ORIONID METEOR SHOWER: Next weekend, Earth will pass through a stream of debris from Halley's Comet, source of the annual Orionid meteor shower. Forecasters expect 25 meteors per hour when the shower peaks on Oct. 21st. [video] [full story]
GEOMAGNETIC STORM UNDERWAY: A G1-class geomagnetic storm is underway on Oct. 13th. Reports of bright auroras have been received from Scandinavia, Greenland, Canada and several northern-tier US states. Colin Chatfield sends this picture from Saskatoon, Saskatchewan:
"This is from my backyard around 5:00a.m. this morning," says Chatfield. "Never have I seen the auroras so bright, especially from within the city. They were astounding, with purple visible to the naked eye."
The ongoing storm was triggered by a knot of south-pointing magnetism from the sun. During the early hours of Oct. 13th, the knot bumped into Earth's magnetic field, opening a crack in our planet's magnetosphere. Solar wind poured in to fuel the auroras.
More auroras are in the offing. NOAA forecasters estimate a 40% chance of strong polar geomagnetic storms on Oct. 14th when a solar wind stream is expected to blow past Earth. High-latitude sky watchers should be alert for auroras. Aurora alerts: text, voice.
Realtime Aurora Photo Gallery
RADIO STORM ON JUPITER: Two nights ago, there was a storm on Jupiter--a radio storm. Amateur radio astronomer Thomas Ashcraft recorded the event using a shortwave radio telescope located in New Mexico. Click on the dynamic spectrum (a plot of intensity vs. frequency vs. time) to hear the whooshing, crackling, popping sounds that emerged from his telescope's loudspeaker:
Dynamic spectrum courtesy of Wes Greenman, Radio Alachua Observatory
"Listen to the recording in stereo," advises Ashcraft. "I recorded the audio from two separate radios at 21.1 MHz and 20.9 MHz, so there is a stereo spatial effect from the frequency drift of the emissions."
Jupiter's radio storms are caused by natural radio lasers in the planet's magnetosphere that sweep past Earth as Jupiter rotates. Electrical currents flowing between Jupiter's upper atmosphere and the volcanic moon Io can boost these emissions to power levels easily detected by ham radio antennas on Earth. Jovian "S-bursts" and "L-bursts" mimic the sounds of woodpeckers, whales, and waves crashing on the beach. Here are a few audio samples: S-bursts, S-bursts (slowed down 128:1), L-Bursts
Now is a good time to listen to Jupiter's radio storms. The distance between Earth and Jupiter is decreasing as the giant planet approaches opposition on Dec. 3rd; the closer we come to Jupiter, the louder it gets. NASA's Radio Jove Project explains how to build your own receiver.
DRACONID METEOR OUTBURST: On Oct. 8th, more than 2000 meteors per hour exploded across the skies of North America and Europe. Radars in Canada and Germany detected the outburst of Draconids, yet sky watchers saw almost nothing. The meteors were too dim for human vision. Nevertheless, a meteor camera in Serbia captured visual evidence that an outburst was underway:
These seven Draconids appeared over the Petnica Science Center at the Institute of Physics in Belgrade. They were the bright "tip of the iceberg" marking the presence of an underlying stream of much dimmer and more numerous meteoroids. Researchers believe the outburst happened when Earth passed through a stream of dusty debris from Comet 21P/Giacobini-Zinner, parent of the annual Draconid meteor shower. This particular stream was laid down by the comet when it passed by Earth's orbit in 1959.
Realtime Space Weather Photo Gallery
Realtime Noctilucent Cloud Photo Gallery
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