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(meteorobs) Re: NM 2002 Leonids partly cloudy in Texas

Joan and I went out to Texas for the 2002  Leonids.  Knowing in advance that
North Florida was the best place to be would have qualified us as prophets.
I thought that more time was needed to insure the peak would not be missed
or cut short by twilight.  Our goal was to be midway between Houston and San
Antonio, away from the big city lights plus far south enough to not freeze.

As it turned out, a dry cold front was due through around sunset of the big
night, but the trailing cirrus clouds were too slow to depart.  We ended up
watching Leonids in clear breaks of 30% at first, improving to 60% later.  I
skipped recording due to the uncertain conditions so am limited to a
qualitative impression.  The peak seemed to be on schedule with the best
minute right after 440 AM CST having about 10 Leonids.  By 5 AM we saw only
an occasional Leonid so the show dropped off very quickly.  I was surprised
at how many faint Leonids were visible despite the moon, although having it
cloud-covered made the sky darker where clear.  There were several +5m's and
gobs of +4m's.  Hardly any brighter than +2m, although very late we saw a
blue-green  -6m overhead with a 2-minute train.  I was looking low west and
saw the landscape light up from the meteor at the fringe of my vision.
Total Leonids seen I am guessing at 150 in about an hour, with potential
easily twice that.   Joan actually counted 65 but was watching part of the
time from inside the car.

We were next to a small airfield.  I managed to park a bit too far off the
road and got two wheels stuck in mud.  We had to wait until just after
sunrise, when a good Texan equipped for pulling hauled us out in a matter of
minutes.

Jeff Corder is a new engineer at Florida Power & Light, living near St.
Augustine.  He is a very experienced telescope user, and he sent an
interesting report :

>BRANDON, GEN AND I WATCHED THE LEONIDS FROM 4:10 AM TIL 6:00 AM THIS
>MORNING.
>EASILY THE BEST METEOR SHOWER I CAN REMEMBER !
>ROUGHLY SEEING 250 -300 PER HOUR, BRANDON COUNTED 500 IN 1.5 HOURS, EVEN
>WITH FULL MOON.  OFTEN SAW 3-5 IN 1 SECOND.  LOTS OF WONDERFUL 30
>SECONDS-LONG BURSTS WHERE WE'D COUNT 20+ METEORS.  SAW ONE VERY WONDERFUL
>-3 MAG POINT METEOR.
>
>CAN NOT IMAGINE WHAT IT WOULD HAVE BEEN LIKE WITH NO MOON IN THE SKY.  AT
>TIMES I GOT THE FEELING IT WAS RAINING METEORS, LIKE THOSE REPORTS OF OLD.
>ALSO GOT THE DISTINCT IMPRESSION THAT THE EARTH WAS MOVING TOWARD THE
>RADIANT, LIKE BEING IN A CAR GOING ALONG THE HIGHWAY.  BRANDON SAID WE NEED
>TO TURN ON THE EARTH'S WINDSHIELD WIPERS !!

Brandon is about 7 years old, I think.  This impression has been used in
past Leonid storms.

The faintness of the Leonids brings to mind the post-1966 displays, which
were also described as faint.  I didn't get to see any of them.  1967 was
cloudy with bright moon in my last year with Florida State, then the next
three years at Univ of Mississippi were all cloudy.  (Ironically I saw the
Geminids all three years there.) 

The faint meteors also give the key to understanding why Mike Linnolt did
not see much from Hawaii.  Paul Jones is the first to mention this.  The ZHR
formula breaks down for faint showers below about 20 degrees elevation.
When the radiant is low, the faint ones just don't show up.  Earthgrazers
are almost all bright.  I find that earthgrazers are rarely fainter than
+3m.  Eta Aquarids can give a  +4m grazer, and I recall a  +5m once which
went 20 degrees.  The formula needs to be revised for dealing with faint
showers from low elevations.

Good Leonid showers have a few years to run yet.  In the previous epoch, I
saw 40/hour in 1974, a full 8 years after the 1966 storm.  A complete
surprise, 1974 was also rich in bright Leonids and long-enduring trains.
This was also the night of my best earthgrazing Leonid ever, going 140
degrees in 8 seconds !

Norman



Norman W. McLeod III
Staff Advisor
American Meteor Society

Fort Myers, Florida
nmcleod@peganet.com

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