Perseid Meteors vs. the Supermoon
 
July 28, 2014:  Every year, sky watchers and summertime campers circle on
their calendars a few key August nights-the 11th, 12th and 13th.  These are
the dates of the annual Perseid meteor shower, which rarely fails to please
those who see it.
 
This year they're adding a note: "supermoon."
 
During the second week of August, the biggest and brightest full Moon of
the year will face off against everyone's favorite meteor shower-and the
outcome could be beautiful.
 
http://youtu.be/JkKzMAzT5fs
 
A new ScienceCast video previews the competition between the supermoon of
August and the 2014 Perseid meteor shower.  Play it
 
The source of the Perseid meteor shower is Comet Swift Tuttle. Every 133
years the huge comet swings through the inner solar system and leaves
behind a trail of dust and grit. When Earth passes through the debris zone,
specks of comet-stuff hit the atmosphere at 140,000 mph and disintegrate in
flashes of light. These meteors are called Perseids because they fly out of
the constellation Perseus.
 
In a normal year, dark-sky observers typically count more than 100 Perseids
per hour.  But this is no normal year.
 
On August 10, 2014, just as the Perseids are set to peak, the Moon will
become full. Moreover, it will become full just as it reaches the place in
its orbit (perigee) that is closest to Earth.  The perigee full Moon of
August 10th -also known as a supermoon- will be as much as 14% closer and
30% brighter than other full Moons of the year.
 
"This is bad news for the Perseids," says Bill Cooke of NASA's
Meteoroid Environment Office.  "Lunar glare wipes out the
black-velvety backdrop required to see faint meteors, and sharply reduces
counts."
 
But there's good news, too.
 
http://tinyurl.com/o8m67ng
 
Since 2008, the Perseids have produced more fireballs than any other annual
meteor shower. The Geminids are a close second. See the dataThe debris
stream of Comet Swift-Tuttle is broad, and it is possible to see Perseids
as early as late July, well before the Moon becomes full.
 
Also, notes Cooke, "the Perseids are rich in fireballs as bright as
Jupiter or Venus. These will be visible in spite of the glare."
 
Using a network of meteor cameras distributed across the USA, Cooke's team
has been tracking fireball activity since 2008, and they have built up a
database of hundreds of events to analyze. Their data show the Perseids are
the undisputed 'fireball champion' of annual meteor showers.  "We see
more fireballs from Swift-Tuttle than any other parent comet," he
says.
 
A warm summer night, a moonlit landscape, and an occasional fireball
cutting past a supermoon: that's an ensemble with a special beauty all its
own. Enjoy the show.
 
Credits:
Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:
Science{at}NASA
 
Related video:
 
Summer Supermoons -- from Science{at}NASA
 
 
Regards,
 
Roger

--- D'Bridge 3.99