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(meteorobs) Fireball Reporting part 2
(continued from part 2)
SPECIAL PROJECTS
The immediate major reason that I should be noti-
fied about bright meteors (Fireballs)...
1)If the reports are received within 7 days, the International
Meteor Organization can obtain satellite data from the Dept. of
Defense before the tapes are erased.
For this purpose, certain types of fireball events are of most
interest....namely if:
THE REPORTED FIREBALL IS -10 OR BRIGHTER IN MAGNITUDE WHICH PRO-
DUCED SONIC BOOMS OR RUMBLINGS AND/OR IF IT WAS A DAYTIME FIRE-
BALL.
To speed up the process to insure that this info gets passed on
in a timely manner, please leave a posting so that others who
are on the look out for such data has a chance to find this info
and email me as well...plus you email me at: GeoZay@aol.com
_________________________________________
_________________________________________
DATA GATHERING FOR METEORITE RECOVERY
George Zay
email: GeoZay@aol.com
January 1996
_________________________________________
It is estimated that about 24,000 meteorites will strike the earth
earth each year ranging in size from 4 ounces to 20 lbs. Three-
fourths of these will be lost in the oceans, with 7500 to fall on
land. If you are lucky enough to witness a meteorite producing
meteor, recording good data should be hot on one's mind for it's
recovery.
__________________________________________
Unless the meteorite landed in an urban area, accurate fall data
is needed for any chance of a meteorite to be recovered. Potent-
ial meteorite falls often occurs during the daylight hours. These
Meteors are as bright as a full moon (-12 magnitude) or brighter
and are accompanied by sonic booms and distant rumbling sounds.
These sounds can occur very shortly after the meteor's passage
or up to several minutes later. These meteors also have relative-
ly slow velocity and don't produce a terminal burst.
In these cases, alt-azimuth measurements should be made. After a
sighting one seldom has a compass or clinometer on hand to make
altitude and azimuth readings. What is available is one's arm
and hand. What the observer should do is carefully mark points on
his hand with an outstretched arm for altitudes and note various
landmarks on the horizon for the azimuths. Also be sure you re-
member where you're at when making these measurements. In addi-
tion, record the exact time to the closest second...even if you
have to estimate. It is most important to record the point where
the meteor's light is extinguished. This is the retardation point
or where the meteor loses it's cosmic velocities and becomes a
falling rock under the earth's gravitational force. With hand mea-
surements note the beginning and ending of the meteor's path. Get
both the altitude in relation to points on your hand and the azi-
muth in relation to distant horizon landmarks. After sighting a
possible meteorite producing meteor, be prepared for any sonic
booms or rumblings to occur by noting the time of their occurren-
ce. If you kept your wits about you and noted the positions,
write them down as soon as possible along with a time. Also note a
rough estimate of the meteor's velocity. The key thing is to re-
gain your composure after the initial sightings so that you can
do all these important things that might help find any meteorit-
es later. After being satisfied about your preliminary data, you
should then try to get an accurate compass reading for your
distant horizon landmarks for the azimuths (0-360). Next you
want to get a clinometer to convert your hand measurements into
degrees for altitude. You can hang a weighted string from the
center of a protractor. Sight along the straight edge part to
the corresponding area in the sky. Read the degrees (0-90) mark-
ed off by the string and subtract your reading from 90 degrees
and these will be your altitude readings with a simple protrac-
tor. The last thing you should do is find your exact position on
a topography map when the meteor made it's appearance. Find your
longitude and latitude in degrees, minutes and seconds.
By itself, if you done the above, your efforts could be an import-
ant piece to the puzzle. After securing your data, you can make
more gains by trying to find other's who also sighted the same
meteor from other locations. Several observations from various
distances apart can be very helpful in determining a possible
strewnfield area. If you can find these individuals from the var-
ious news media, try to secure the same data from them as you
have for yourself. Be sure to have them show you where they were
when they saw the meteor. Use your compass and homemade clinome-
ter to convert their arm gestures into degrees.
When you have secured all the data you can, mail it to Andre Kno-
fel at the Fireball Data Center or to me. If the sighting be-
comes significant, he will be in contact with those who can make
use of the data. Below is a simple summary of what's needed for
daytime/or sonic boom producing meteors. If you can note addi-
tional fireball data not mentioned above, that's great! But the
most important is what's listed below.
1) Altitude for Beginning and Ending points of the meteor.
2) Azimuth for Beginning and Ending points of the meteor.
3) Longitude and Latitude in degrees, minutes and seconds for the
position of each observer.
4) Estimate Speed (Slow, Medium or Fast)
5) Times.