(meteorobs) old fireball

[Dave Hostetter]

I had an interesting conversation about a meteor with a visitor to my
planetarium yesterday.  As background, there was a tremendous meteor visible
in the southeastern USA on the evening of March 15, 1957.  I've seen many
reports from Alabama to Louisiana along with some from surrounding states
(the local newspaper articles make interesting reading and are probably in
local libraries along the path).  It was so bright that we regularly get
questions about it even now, from people who saw it or who remember hearing
their parents talk about it.  In fact, we get so many questions that when we
revamped our meteorite and tektite exhibit recently, we included a panel
about it.  It draws a lot of comment from people who saw the fireball.

The man I talked with thought he had meteorites from the event.  He had been
a teenager in a school science club at the time, and a local farmer had
called the science club the next day to report seeing rocks falling all
around him...did the club want them?  The club members went out and
collected dozens of them, and my friend still had his after more than 50
years!  Unfortunately they turned out to be slag, but his description of the
meteor was good.  

This guy is an accomplished local amateur astronomer and life-long science
lover, and I think he could give me an accurate report.

He described the fireball as much brighter than the moon, lighting the
ground almost like daylight only bluer.  He and his parents watched the
event from their car, stopped at a stop sign in town.  He estimated the
apparent size of the head of the meteor as slightly greater than the width
of a thumb at arm's length, and watched as the shape changed from nearly
round to something like a stretched teardrop.  He saw bright "chunks" coming
off like sparks.  He described both a sizzling sound and a shock wave boom.
The boom came a couple seconds after the meteor but the sizzling sound was
simultaneous with it, so seems to have been electrophonic.  I questioned him
carefully about that, and he was quite sure of it although he had never
heard of the possibility of electrophonic sounds. 

After the meteor, his family drove home, which was essentially around a
short block.  They got out of the car, and as they went up the steps to
their porch they felt the ground shake.  He was quite specific that this was
a seismic event rather than an airborne shock wave because they had already
heard that and because this shaking was silent.  That's the part that I
found really interesting, and a detail I had not previously heard.  I drove
from the intersection where they saw the meteor around the block to his old
house, and it took about a minute.  Throw in some time to get over their
surprise after seeing the meteor and time to get out of the car and cross
their yard, and I figure that seismic event was about 1 to 3 minutes after
the fireball.  There was a seismic event recorded about 50 miles south that
may or may not have been related to the fireball (which, based on other
reports, had to go out over the Gulf of Mexico), but I've got no other
reports of anyone feeling anything in the distance between.  I have to
wonder if the ground shake might have been something else.  One to three
minutes seems like a LONG time under the circumstances.

Anyway, it was an interesting conversation about a long ago event, but I
thought some of you might like to hear about it.

Dave Hostetter
New Iberia, LA