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THREE CMEs: A sequence of magnetic filament eruptions around the sun's western limb propelled three CMEs into space on Nov. 3rd. Click on the image to view a SOHO coronagraph movie of the expanding clouds:
Only one of the CMEs appears to be (slightly) Earth directed. If so, it would add to the impact of a minor solar wind stream already en route to our planet, due to arrive on Nov. 4-5. Arctic sky watchers should be alert for Northern Lights in that time frame. Magnetic storm alerts: text, voice.
TAURID FIREBALLS: Sky watchers should be alert for fireballs in the nights ahead. Forecasters say Earth might be heading for a swarm of gravelly debris from comet Encke. If so, meteoroids the size of pebbles and small stones hitting Earth's atmosphere at 25 km/s would produce a slow drizzle of very bright fireballs flying out of the constellation Taurus--hence the name "Taurids." The display is expected to peak with a few fireballs every hour during the nights of Nov. 5-12.
NASA's network of all-sky meteor cameras is already picking up some Taurid fireballs--"6 last night and 17 altogether since Halloween," reports Bill Cooke of the Meteoroid Environment Office. Here are their orbits:
In the orbital diagram, the location of Earth is denoted by a red splat. The orbits of the meteoroids (yellow) roughly match that of parent Comet Encke (orange), confirming their association with the Taurid debris swarm.
"What always strikes me about the Taurids," notes Cooke, "is how deeply they penetrate Earth's atmosphere. On average, they make it to an altitude of 44 miles. Contrast this to the recent Orionids, which burn up at an average altitude of 58 miles. Part of this is due to the speed difference: Taurids are slow (27 km/s) while Orionids are fast (66 km/s). In addition, many Taurids are made up of stronger stuff than the Orionids."
On Nov. 1st, Cooke received this report from a hunter in Tennessee, who was near the terminus of a Taurid fireball which made it all the way down to 18.5 miles altitude: "On the morning of October 30 at approximately 6:00 CDT I was walking into a hunting spot in the middle of the Hatchie National Wildlife Refuge. As I was standing, this bright white light appeared from the north, illuminating the woods like daylight, casting shadows of the trees, and as it passed overhead in a couple of seconds, the shadows quickly reversed direction. It was so intense I felt like a searchlight from an overhead helicopter was on me, but there was no noise. As it disappeared into the southern sky, I heard three extremely loud booms which I also felt much like a sonic boom from a plane. The resident birds all began to call for a minute after. In my 62 years of living on this planet, and witnessing several meteor showers- some very bright- I can tell you I have never witnessed anything like this. The experience was not totally unlike that seen in the movie Close Encounters of the Third Kind when the man's truck was stopped at a railroad crossing and he was engulfed in light!"
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AMAZING ICE HALO DISPLAY: On Oct. 30th, sky watchers around the Marshall Space Flight Center in Huntsville, Alabama, witnessed something amazing: A complex network of luminous arcs and rings surrounded the afternoon sun. "I've never seen anything quite like it," says eyewitness Bill Cooke, head of NASA's Meteoroid Environment Office. Solar physicist David Hathaway snapped this picture of the display:
Image credit and copyright: David Hathaway/NASA/MSFC
The apparition is almost certainly connected to hurricane Sandy. The core of the storm swept well north of Alabama, but Sandy's outer bands did pass over the area, leaving behind a thin haze of ice crystals in cirrus clouds. Sunlight shining through the crystals produced an unusually rich variety of ice halos.
"By my count, there are two sun dogs, a 22o halo, a parahelic circle, an upper tangent arc, and a parry arc," says Chris Brightwell, who also photographed the display. "It was amazing."
"Very impressive," agreed onlooker Kyle Winkleman. "This was a once-in-a-decade event for our area."
It might not be necessary to wait another decade for a repeat performance. Some researchers believe that superstorms will become more common in the years ahead as a result of climate change, creating new things both terrible and beautiful to see overhead. Sky watchers in the storm zone should remain alert for the unusual.
UPDATE: Atmospheric optics expert Les Cowley comments on the Sandy-ice halo link: "Over the last few days there have been spectacular halo displays around the edge of Sandy from New England to Alabama. Hathaway's image like many others shows several very rare halo arcs, an upper Lowitz, helic and Parry supralateral."
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