(meteorobs) Forwarded fireball report from Virginia
Thomas Ashcraft
ashcraft at heliotown.com
Wed Aug 6 09:38:00 EDT 2008
I am forwarding this report that was sent to me by an observer in
Virginia. - Thomas Ashcraft
:::::::::::::::::
Hello,
I saw and heard(!) a bright fireball from Yorktown, Va on 04 Aug 2008 at
0159 UT. Does someone collect these types of sightings? I don't know
if anyone is interested, but the particulars follow:
My location: 76d 33m 22.5s W; +37d 16m 06.3s N; 3m elevation (Google Earth)
Time: Aug 3, 2008 at 9:59 EDT (2008 Aug 04 0159 UT) - give or take 1
minute.
Description:
I had just finished setting up a TeleVue sdf 4" refractor at a road-side
pull-off from the Colonial Parkway to work on the Astronomical League's
Double Star observing program, and was getting some eyepieces laid out.
I try to avoid looking at bright lights so I can get dark adapted, and
was annoyed that something was shining a bright light at me. With my
head turned away, I saw enough light to see my shadow - I though it was
a Park Ranger shining a spot or a car pulling into the turn off. Then I
figured the illumination was coming from too high an angle - my shadow
was cast down into my eyepiece box. When I turned, I heard a sizzling
sound and saw two broken trails of meteor light, nearly colinear, but
they were separate white and bright green streaks. Each trail was
broken - dashes of varying lengths of green along one path or white
along the other line.
Since this illuminated my surroundings better than the full moon, I'd
estimate it at brighter than -10 magnitude. The sections were running
next to each other, reminiscent of the Shuttle re-entry breakup over
Texas a few years ago. No post-event trails (smoke) were seen. When I
turned, the light had been in progress for just a second or two
(impression - not measured). The meteor path I witnessed ran below the
W of Cassiopeia and into Camelopardalis. Afterward, I ran Starry Night
and estimate the fireball was seen from Az = 38 deg, El = 23 deg over to
down and northward at Az = 11 deg, El = 16 deg as it continued to break
up. It must have originated much higher and more eastward. There is a
body of water just about 90 yards away in that direction (York River),
followed by more land (Gloucester shore is 2.5 miles east), and then the
Chesapeake Bay (17 miles away). I did not see impact, as it appeared to
burn out at 16 deg elevation.
I'm confused by the audible report. I've heard just one fireball in the
past, but that was more than 20 years ago. That one was more of a pop
or bang as opposed to this fairly soft sizzle sound. The sound vs light
speeds also would indicate this was nearby, but the sound quit before
the visual faded. I heard the sound as I turned around - so it was
delayed from me being cognizant of the light by only a few (< about 2?)
seconds. This is by impression - not by timing. No photo or video
records were made.
Please forward as you see fit.
Regards,
Mark Croom
mark.a.croom (at) nasa.gov
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