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(meteorobs) Re: leap year Geminids + shuttle launch seen



Timing for the Geminids in a leap year changes by a day from the previous
year.  The difference is dramatic, and I have seen it well in 1972, 1976,
1980, 1984, 1988, and 1996.  The night for highest Geminid rates in U.S.
longitudes is Dec 12/13 in a leap year.  Then Dec 13/14 is only half as
strong but the Geminids are much brighter.  By Dec 14/15 only a few remain,
possibly as high as 10/hr when the radiant is high.  For the mid-evening
hours this is the year's best shower by far.

The full moon changes when the best rates are seen this year.  I would
expect the late PM hours of Dec 13/14 to show the highest numbers because of
the bright Geminids coming then and the moon not yet overhead. One hour
should reach maybe 25 Geminids while the moon is still low.  The
earth-grazer period begins around 730 PM in Florida, earlier going
northwards, with spectacular long-pathed Geminids coming from ENE.   Dec
12/13 has mostly faint Geminids which will be washed out by the moon.  In
past years with the moon at, or nearly full, I tend to see Geminid rates in
the high teens at best.  1981 and 1978 were good examples of that. 

 In 1962 with a Geminid full moon I watched from the living room at home in
Miami (saw about 10 Geminids in an hour out the closed window)  because the
great Florida freeze was taking place that night.  The Miami morning low was
35oF, coldest I had ever experienced from Florida at that point.  Fort Myers
had its all-time low the same morning, 26oF.

Joan and I saw the past two shuttle launches from a nice spot along the
river, perfectly oriented to give a low NE horizon where we need to look.
It is only a mile to the viewing site.  We are 150 miles SW of the launch
pad so it is a rear-end vantage point.  The last launch began as a  -8m
intense orange fireball half a degree wide, initially appearing slightly
left of the highest part of the US 41 bridge crossing the mile-wide
Caloosahatchee River.  Only the bottom two degrees is blocked.  It rose to a
maximum elevation of 12 degrees, then the boosters separated and fell away
as a close pair of orange-red  +2m stars.  Appearance changed to a  -4m
green streak about a degree long.  After a minute more it changed to a  -4m
white-blue star, gradually shifting rightward and setting.  Getting lower it
gradually faded, twinkled more violently, and flashed numerous colors like
Sirius.  Acceleration was readily apparent in the last 5 degrees of
visibility.   It disappeared behind the bridge as an orange  +1m star,
shining through a bit of low-level smoke.  In azimuth it had shifted 10
degrees to the right.

We saw two other people walk out on a nearby pier minutes before the launch.
They had their backs turned to the show when it began, so Joan yelled to
them to turn around and look.

The previous launch was unique in going up during evening twilight.  The sun
had set about 20 minutes earlier, and the earth's shadow rising in the east
provided a nice dark backdrop.  The vapor trail was completely visible, but
the best part was seeing the shuttle break into sunlight  2/3 of the way up.
It was like a shuffled columnar rainbow with almost every color showing up
somewhere along the trail : dark blue at the bottom, orange in the middle,
shifting to bright yellow at the top.  A lot of people got to see this one
and commented on its unusual beauty.

I failed to get an error-free report out last time, once again.  The last
hour of 2000 Nov 30/1, 426 - 526 EST, should have been 19 total meteors
seen, not 15.

Norman



Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod@peganet.com

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