[meteorite-list] Meteorite Leaves Trail Of Fire, Confusion

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:34 2004
Message-ID: <200107242146.OAA11334_at_zagami.jpl.nasa.gov>

http://www.cnn.com/2001/TECH/space/07/24/fire.ball/index.html

Meteorite leaves trail of fire, confusion
By Richard Stenger
CNN
July 24, 2001
5:18 PM EDT (2118 GMT)

(CNN) -- A streaking fireball or fireballs witnessed over much of the
eastern United States seems to have disappeared without a trace, save
perhaps for strange markings in a Pennsylvania cornfield.

A swath of stalks with possible burn pocks was cordoned off Tuesday, as
state environmental authorities combed the area with radiation detectors.

Space enthusiasts -- including at least one from the air -- tried without
luck to approach the guarded site. Shooting video from a helicopter, Jeramy
Mohler swooped in close to the spot when someone with a megaphone told him
to "move away from the contaminated area," he said.

The scene had been abuzz since the early evening before. From Ontario to
Virginia, eyewitnesses saw a brilliant, colorful fireball blaze across the
sky between 6 and 6:30 p.m. EDT. Some reported hearing a loud sound or
series of sounds akin to sonic booms.

Shortly thereafter, witnesses watching deer near Williamsport, Pennsylvania,
said they saw a fireball fall into the cornfield. A volunteer at the Larry's
Creek Fire Department went to the scene.

Curled corn, dark rocks

"There was an obvious patch, about 25 yards by 50, that was covered by ash
and was knocked down. The corn had bb-like holes in it and some of it was
curled," said A.J. Edkin, a department safety officer, recounting the
description of her colleague.

But did something really land there and, if so, what? Meteorite fragments
have yet to be recovered. The corn, first described as flattened, scorched
and dusted, had rebounded to an almost pristine condition by the morning.
Air quality and radiation checks turned up nothing.

Not that they would.

"You're not going to see any signs of radiation with a meteorite," said
meteorite expert Ron Baalke. "People think they are radioactive and they are
not."

Instead searchers should look for "dark rocks with dark fusion crust,
basically the result of burning up in the outer layer of the atmosphere," he
said.

"This fireball is a very good candidate for having landed on the ground as a
meteorite. It has all the classic signs of a meteorite fall," the NASA
scientist said.

So far only a few black singe marks on individual stalks and the hint of
recent turbulence suggested something was amiss. Local emergency personnel
concluded that a meteorite had struck the cornfield. But state authorities
said they were not inclined to pursue an investigation.

"Some cornstalks have been blown over, but they don't seem burned. There's
not much to look at," said Marko Bourne, spokesperson for the Pennsylvania
Emergency Management Agency, on Tuesday.

"There are a few (cornstalks) that looked withered. It might have been
totally unrelated to what was traversing the sky last night."

Richard R. Erickson, an astronomy professor at nearby Lycoming College,
thinks there definitely was a connection.

"My wife and I heard a loud noise. We thought it was a sonic boom of some
sort," he said. "I'm almost certain it was some kind of meteor."

Erickson and other astronomers speculate that a speeding meteor pierced the
atmosphere, broke into parts as the atmosphere heated it and slowed it to
well under the speed of sound.

Single meteorite theory

Eyewitnesses described the object as large as an SUV or even airplane. But
astronomers said the object or its main pieces were most likely much
smaller.

"When you have a small object traveling at an incredibly high velocity,
slamming into the earth's atmosphere, the friction makes the speeding object
heat up so much that it can internally fracture and turn into what we call a
fireball," said Jack Horkheimer, director of the Miami Planetarium.

"You don't need a big object. Something the size of a golf ball, a baseball,
or even a basketball could look as big as a jeep or flaming bus."

Many mysteries remain. Conflicting accounts on the time and direction of the
fireball have given rise to speculation that more than one space object
stunned onlookers Monday.

Most eyewitnesses said the object traveled from the north to the northwest,
but at least one said it went from east to west. And many of the sightings
could be grouped into one of two distinct time periods -- just after 6 p.m.
EDT and one between 6:25 p.m. and 6:30 p.m. EDT.

Perhaps it was a mini-meteor shower?

"There are three minor meteor showers going on, one known for slow moving
but very bright fireballs," said Horkheimer. However, he and other
astronomers leaned toward the lone-meteor theory, attributing eyewitness
inconsistencies to human error.

-----------------------------------------------------
  Confused by space rock terms?

* A meteoroid is a pebble or stone in space.
* A meteor is the bright flash of light that a
  meteoroid produces as it streaks across the sky
  and also refers to the stone itself while in
  the atmosphere.
* A meteorite is a meteor that survives its fiery
  atmospheric entry and strikes the Earth's surface.
-----------------------------------------------------

'Seekers and lookers'

Another question puzzling astronomers -- did the object or objects land?
There is a good chance that none of the parts survived long enough to reach
the ground.

"I don't think a meteorite per se could scorch the field like that. If it
somehow exploded above the ground, it could have generated a heat pulse that
could have scorched the ground," Erickson said.

And if they did, they could have struck great distances from the cornfield,
Baalke added.

Nevertheless, Lycoming County emergency personnel kept the location of the
field under wraps to prevent the curious from tromping through the corn.

"We've not given the name of property owner because of the seekers and
lookers," Edkin said.

CNN Science and Technology Executive Producer Peter Dykstra contributed to
this report.
Received on Tue 24 Jul 2001 05:46:29 PM PDT