Every year thousands of meteorites fall to the earth as meteorites. Only a very small fraction are ever recovered, and even fewer immediately after they fall. Yet there is great value in recovering meteorites quickly, since they contain volatile chemicals that can tell us much about early conditions in the Solar System.

Meteoroids large enough to produce material that can survive to the ground produce brilliant displays called fireballs, which are seen in either the day or the night. Although these light shows may be seen by many hundreds of people, it remains difficult to determine where meteorites might have fallen. Scientists at the Denver Museum of Nature and Science over the last 75 years have perfected techniques for interviewing witnesses and determining the approximate path of fireballs. In this way, several meteorites have been recovered, but most remain lost. For example, what may have been the brightest fireball ever seen over Colorado lit up the sky at 10:44 PM on 17 August, 2001. This event was seen by hundreds of people. Many were visited by Museum researchers, their statements recorded, locations measured, and bearings taken. This produced a map of the likely fall area that narrows things down fairly well. Or so it might seem. Unfortunately, the area identified here is still over 200 square km, in rugged mountains. Although we believe that more than 10 kg of material reached the ground, it is unlikely that it will ever be found.

In addition to helping locate fresh meteorite falls, an allsky camera can provide valuable information about the kind of meteors you can see on any clear night, and about annual meteor showers. I was operating two cameras in the Guffey area during the 2001 Leonid meteor storm. This image is a composite of a number of Leonids, including one huge fireball.

The two cameras between them recorded over 650 meteors. This data has been analyzed to produce a histogram that accurately shows how the meteor rate varied with time, and precisely when the peak occurred.

See my Meteor Shower page for more information about showers and for images from past showers.

2001 Leonids
2001 Leonid Activity