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KILLER APP: You can now experience the Perseid
meteor shower on your iPhone. It's cloud-proof! Learn
more and give
it a try. |
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AURORA WATCH:
A solar wind stream is buffeting Earth's magnetic field. High-latitude
sky watchers should be alert
for auroras.
METEOR UPDATE: Perseid
meteors are now hitting Earth's upper atmosphere with a speed of
58 to 60 km/s, about 130,000 mph. That's the result of triangulation
by a dual-station meteor monitoring system operated by NASA's Meteoroid
Environment Office. Last night the system detected five fireballs
that provided the data for this speed estimate.
EARLY PERSEIDS:
The Perseid meteor shower is slowly intensifying as Earth plunges
deeper in Comet Swift-Tuttle's debris stream. On August 4th, amateur
astronomer Thomas Ashcraft caught an early arrival using an all-sky
camera at his observatory near Santa Fe, New Mexico. Click on the
image to play a movie with sound effects:
The "ping" you just heard was a 61.25 MHz
TV signal bouncing off the meteor's ionized tail. Ashcraft keeps
an antenna trained on the sky so that he can record the echos and
lay them down as soundtracks for his all-sky movies. "I'm sure
I'll record many more in the days ahead," he says. "Highlights
will be posted here."
According to the International Meteor Organization,
about 10 Perseids per hour are now streaking across the night sky:
data. This number
could increase to as many as 200 per hour when Earth crosses an
anticipated filament of comet dust around 0800 UT (1 a.m. PDT) on
August 12th. Observing tips and a sky map may be found in the Science@NASA
story "The
Perseids are Coming."
2009
Perseid Meteor Gallery
[previous Perseids: 2008,
2007, 2006,
2005, 2004,
2001]
BLANK IS BEAUTIFUL:
The sun is entering its 27th consecutive
day of spotlessness, quiet and calm. That's okay. According to astrophotographer
Greg Piepol of Rockville,
Maryland, blank is beautiful:
"I took this picture on August 4th using my Coronado
SolarMax90," says Piepol. "It was a pretty sight uninterrupted
by sunspots or other activity."
Indeed, the sun is being remarkably quiet. After a
promising
eruption
of
sunspots
in early July raised hopes that Solar Cycle 24 was gaining strength,
the sun reversed course and retreated to peaceful slumber. Only
four weeks after behemoth sunspot 1024 amazed onlookers, solar minimum
has never seemed deeper. The sun's 77% rate of spotlessness in 2009
confirms the ongoing minimum as a century class event.
2009
Noctilucent Photo Gallery
[previous years: 2008,
2007, 2006,
2005, 2004,
2003]
July
2009 Aurora Gallery
[previous Julys: 2008,
2007, 2006,
2005, 2004,
2003]
Explore
the Sunspot Cycle
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