I suspect that many ATS members are well aware of the impending Perseid Meteor shower we should be witnessing this weekend...
On the nights of Aug. 11th through 13th, the best meteor shower of the year will fill pre-dawn skies with hundreds of shooting stars. And that's
just for starters. The brightest planets in the solar system are lining up right in the middle of the display.
The Perseid meteor shower peaks on the nights around August 12th as Earth passes through a stream of debris from Comet Swift-Tuttle.
"We expect to see meteor rates as high as a hundred per hour," says Bill Cooke of NASA's Meteoroid Environment Office. "The Perseids always put on
a good show."
Perseids can be seen any time after 10 to 11 pm. The best time to look, however, is during the dark hours immediately before dawn.
I have to confess to jealousy for those of you will see it... my local forecast calls fro dense cloud cover (among other annoyances) ... but there is
some more "bonus" stuff going on up there worth a look for the amateur astronomer in all of us....
This year's display is extra-special because of the planets. Jupiter, Venus, and the crescent Moon are gathering together just as the Perseid
meteor shower reaches its peak. The alignment occurs in the eastern sky before sunrise on the three mornings of highest meteor activity.
On August 11th, a 33% crescent Moon will glide by Jupiter, temporarily forming a bright pair directly above brilliant Venus. Red-giant star Aldebaran
will be there, too, adding a splash of color to the gathering.
August 12th, the narrowing 24% crescent Moon will drop down between Jupiter and Venus. Together they make a bright 3-point line in the sky, frequently
bisected by shooting stars.
On August 13th, with the shower just beginning to wane, the planets put on their best show yet: The 17% crescent moon will pass less than 3 degrees
from Venus as Jupiter hovers overhead. Sky watchers say there's nothing prettier than a close encounter between the slender crescent Moon and
Venus--nothing, that is, except for the crescent Moon, Venus and a flurry of Perseids.
But wait... there's more!
In a recent article another 'something you may be interested in may be seen....
Noctilucent clouds or “NLCs”
Anyone who's ever seen a noctilucent cloud or “NLC” would agree: They look alien. The electric-blue ripples and pale tendrils of NLCs
reaching across the night sky resemble something from another world.
Researchers say that's not far off. A key ingredient for the mysterious clouds comes from outer space.
"We've detected bits of 'meteor smoke' imbedded in noctilucent clouds," reports James Russell of Hampton University, principal investigator of
NASA's AIM mission to study the phenomenon. "This discovery supports the theory that meteor dust is the nucleating agent around which NLCs form."
It turns out that as meteors break up, the dust they trail behind them may be a significant precursor to NLCs, which some have seen and been quite
confused about. Clouds that high reflect sunlight even though on the ground it's dark... and if the theory is correct the dusty smoke may serve as
the 'sticky core' for the accumulation of luminescent (glowing) particles.
The inner solar system is littered with meteoroids of all shapes and sizes--from asteroid-sized chunks of rock to microscopic specks of dust.
Every day Earth scoops up tons of the material, mostly the small stuff. When meteoroids hit our atmosphere and burn up, they leave behind a haze of
tiny particles suspended 70 km to 100 km above Earth's surface.
It's no coincidence that NLCs form 83 km high, squarely inside the meteor smoke zone.
Specks of meteor smoke act as gathering points where water molecules can assemble themselves into ice crystals. The process is called
Nucleation happens all the time in the lower atmosphere. In ordinary clouds, airborne specks of dust and even living microbes can serve as nucleation
sites. Tiny ice crystals, drops of water, and snowflakes grow around these particles, falling to Earth if and when they become heavy enough.
Nucleating agents are especially important in the ethereal realm of NLCs. The clouds form at the edge of space where the air pressure is little
more than vacuum. The odds of two water molecules meeting is slim, and of sticking together slimmer still.
Meteor smoke helps beat the odds. .....
Meteor smoke explains much about NLCs, but a key mystery remains: Why are the clouds brightening and spreading?
Short possible answer: Methane in the atmosphere....