2001 Lunar Leonid Observations
Updated: 2001 Dec. 10 and 2002 Dec. 16
On November 18 at 23h 19m 15s UTC, Roger Venable at Augusta, GA
videorecorded an apparent flash of a meteor, probably a Leonid,
striking the Moon at Lacus Gaudi in southwestern Maria Serenitatis.
It was confirmed by Tony Cook, Alexandria, VA and by myself near
Laurel, MD. Read more about my interesting observation of this
event here. A sequence of my images of the flash
at 1/60th-second intervals is below; it is near the top in the
middle. I estimate that it was 4th to 5th magnitude.
Just before the impact
The impact image
Afterglow, faint
Afterglow, very faint
Gone
On November 19 at 0h 18m 58s UTC, David Palmer at White Rock, NM
(near Los Alamos) videorecorded what appeared to be the flash of a
meteor, probably a Leonid, striking the Moon near the center of its
disk. The observation with a 5-inch Celestron and PC-23C camera was
confirmed in videotapes made with 8-inch telescopes and Watec 902
cameras by Tony Cook, Alexandria, VA and by myself at Laurel, MD.
The flash is in the upper right corner of this image
that Joan and I captured from my recording. The curved dark edge of
the Moon can be seen on the left side, and an out-of-focus telephone
wire about 200 feet away is in the upper right corner. The
observation was made through thin cirrus clouds at an altitude of
only 3.3 deg. above the astronomical horizon. It will be possible to
determine the orientation of the Moon's disk from an image of the
bright crescent taken 3 minutes later shown here.
A minute later, the last of my 3 batteries for the camcorder died,
then I switched to another old camcorder to record the last few
minutes as the Moon set into distant trees on the horizon.
Details of David Palmer's observations, including several images,
can be found here.
More information is given in the edited e-mail messages copied
below.
Palmer recorded several other possible impact flashes, documented
on his Web site, but they occurred after moonset for Cook's and my
locations in the Washington, DC area. Perhaps some will be
confirmed by others who recorded farther west, such as Richard
Nolthenius in California. Others also videorecorded the dark side
of the Moon and have recorded what appear to be impact flashes,
including Jean Bourgeois in the Vosgian Mountains of northern
France, noting a bright flash on Nov. 17 at 17:46:10 UT, and Kiran
Shah using a C-8 and Watec 902 camera at Pune, India. On reviewing
the tape, Shah found about twenty flashes, one especially bright,
between 12:50 and 15:00 UT of Nov. 18. In about two weeks, he plans
to put details of his observations, including impact locations, on a
Web page. In the meantime, he gives further information here
from a recent e-mail message. So far, none of these other possible
impacts have been confirmed. Two lunar impact flashes were also
apparently recorded in Korea at 9:40 U.T. (bright) and 9:51 U.T. of
November 18, near the time of the storm visible from the U.S.A.; here is Christophe Marlot's account of these
events, with a link to his Web page with images. In addition, visual
observations have been reported by Costantino Sigismundi near Rome,
Italy and Walter Nissen, Jr., in Berea, OH. Walter saw no lunar
flashes, but clouds moved in at his location before the impact
recorded by Palmer, Cook, and myself. Costantino reports timing a
lunar flash at 17:05:04 UT of Nov. 17 near Clavius. I have much
other work to do, and will be on travel from Nov. 29 to Dec. 7, so I
will not be able to make any further updates to this Web page before
Dec. 10. In the meantime, Brian Cudnik, e-mail xflare@earthlink.net,
is collecting lunar observation times (visual, video, or other) to
coordinate the search for possible impact flashes for the ALPO Lunar
Meteor Impacts Section, and these are being posted
here
on the ALPO lunar impacts Web site.
_________________________________________________________________
Messages about the confirmed impact flash of Nov. 19, 0:18:58
From: Joan and David Dunham [dunham@erols.com]
Sent: Saturday, November 24, 2001 11:59 PM
To: David Palmer
Cc: IOTAoccultations@egroups.com; planoccult@aula.com;
meteorobs@jovian.com; occultation@skypub.com
Subject: [PLANOCCULT] First confirmed 2001 lunar Leonid impact
David,
At 04:19 PM 11/24/2001 -0700, you wrote:
>Correction, the bright flash was at 00:18:58 UT Nov 19, not 01:18:58 .
>It was roughly equatorial, nearer to the central meridian than to the
>terminator.
- I'm glad that it was at 00:18:58 rather than 01:18:58, since I was
recording with my C-8 and Watec camera at the earlier time. I just
reviewed my tape, and at the time you give, and location, I also
recorded the flash. You were in Los Alamos, NM, recording in twilight,
but for me in Laurel, MD, the Moon was only a few deg. above the
horizon, shining through some thin cirrus, so the lunar features on
the dark side are not as obvious as they were earlier that evening.
But the dark edge of the Moon is visible and it will be possible
to determine the location from my tape. This should encourage
others to review their tapes for flashes as you have done.
Unfortunately, I can't confirm your other events because the Moon
was below the horizon for me, but hopefully others in the central
and Rocky Mountains regions of North America might be able to. It
might help if you can to give approximate locations for your other
events. David Dunham, IOTA
>Currently I have the following flashes, sparkles, and other things worth
>checking out. Except for the 00:18:58 event, none are blatant and
>multiframe, although the rest show brightening on multiple scanlines
>with the interlaced scan lines dimmer.
>
>Saturday evening
>2001 Nov 18 UT 00:56:11
>2001 Nov 18 UT 01:18:47
>Sunday Evening
>2001 Nov 19 UT 00:18:58.4 +/- 0.3 bright <---
>2001 Nov 19 UT 00:46:14
>2001 Nov 19 UT 00:48:13
>2001 Nov 19 UT 00:58:17.2 +/- 1
>2001 Nov 19 UT 01:22:37
>2001 Nov 19 UT 01:24:13
>
>Yet to be analyzed: UT 01:44 until Moonset Nov 18
>
>I will put up a webpage showing locations once I finish the analysis.
> [this has now been done, see above]
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Return-Path:
Date: Sun, 25 Nov 2001 01:24:55 -0700
Subject: David Palmer's flash and candidate page
Cc: IOTAoccultations@egroups.com, planoccult@aula.com, meteorobs@jovian.com,
occultation@skypub.com, pnapplet@iastate.edu
To: Joan and David Dunham
From: David Palmer
OK, I have just put up a web page which shows the times and locations of
the confirmed Lunar Leonid and 9 candidates. Some of these candidates
are better than others.
Anyway, the URL is
http://www.speakeasy.org/~palmer/leonids/candidates.html
The web page is 700k, so I'll split it and proofread it tomorrow.
It includes blow-ups of successive frames of the flash (not fields, so
watch interlace effects), and the locations of the flashes. North is
always to the right, illuminated crescent is always down.
Any confirmations or refutations of candidates are appreciated.
------------------------------------------------------------------
From: Joan and David Dunham [dunham@erols.com]
Sent: Sunday, November 25, 2001 12:13 PM
To: planoccult@aula.com; meteorobs@jovian.com
Subject: [PLANOCCULT] 3rd confirmation of Nov. 19th lunar Leonid impact
Return-Path:
To: Joan and David Dunham
From: "Tony Cook"
Subject: Re: 2001 Lunar Leonids
Date: Sat, 24 Nov 2001 23:57:12 -0500
David,
For observing I managed to have a balcony on an 11th floor
apartment facing West not far from Land Mark mall on 17th & 18th.
This allowed me views down to just 3deg above the horizon.
Video recordings of Moon 2001 Nov 18-19
=======================================
CCD camera used at Newtonian focus of 8" f/5
Dobsonian near Landmark Mall, Alexandria, from
a high rise apartment balcony of a colleage at
work, GPS coords: 77deg 08' 17W,
38deg 48' 35N, 102?m elevation. Wratten 87C used first
during twilight with the PC23C CCD camera, then
switched over to the Watec 902HS CCD camera +
diffraction grating. Mostly the NE section of
Earthshine was videoed. Limiting magnitude of stars visible to
the naked eye was about 4. But of course limiting
magnitude drops off towards the horizon anyway.
Date & duration of video tape ??? - session 7
---------------------------------------------
2001 Nov 19 UTC 23:09:59 - 2001 Nov 19 00:24:35)
(tape time codes 0:37:21:04 - 0:51:56:21
Watec 902HS camera + no diffraction grating nor filter.
2001 Nov 19 00:18:58UTC (Time code 00:46:20:01-00:46:20:03)
Flash lasting 1/10th sec near center
of Moon. Brightness fades with time. Some
whispy, hazy cloud drifting past Moon at
this time, but can still see some
parts of Earthshine. Moon slightly above
3 deg above the horizon at this time.
- in his message, Tony Cook gave times for several
other flashes, most of which he suspected of being
cosmic ray hits; his full message is given here.
The above flash, of course, perfectly matches
the one that David Palmer and I recorded, giving
a triple confirmation for this event. My location
beside Van Dusen Rd. southwest of Laurel, MD was at
long. 76 deg. 53' 40.2" W., lat. +39 deg. 05' 01.1"
height 95m. I had not calculated the lunar altitude
at this location north and a little east of Tony's
site, so it must have been just a little lower than
at his site, or very close to 3 deg.
David Dunham, IOTA
------------------------------------------------------------------
From: David Palmer [palmer@nis.lanl.gov]
Sent: Monday, November 26, 2001 12:29 PM
To: Dunham, David
Subject: Re: Your location?
>David,
> What are the coordinates of the location from which you
>recorded the Moon? You can use http://www.topozone.com
>to obtain coordinates, including height above sealevel, that
>are good enough.
> David D.
6200 feet; 35 deg. 49' 05"N, 106 deg. 12' 42"W - WHITE ROCK
http://www.topozone.com/map.asp?z=13&n=3964244&e=390534&s=25&size=m&u=2
--
David Palmer palmer@lanl.gov (505)665-6863 (voice) (505)665-4414 (fax)
_________________________________________________________________
David Dunham, IOTA, 2002 Dec. 16