LONG DURATION TRAINS
- Subject: LONG DURATION TRAINS
Most meteors last only a fraction of a second, but some leave behind trains that can glow for several minutes. The processes behind long duration trains are not well understood.
Most long duration trains are associated with bright meteors and fireballs. When a meteoroid plunges into the atmosphere at a velocity of between 12 and 72 km/s, the air simply does not have time to flow around the meteoroid and, instead, tears into it. The result is that the atmospheric atoms, and those of the meteoroid, collide releasing electrons to produce a highly charged plasma. However, the ions quickly recombine and any excess energy is released as light – which we call a meteor. The whole process normally takes 0.1 – 0.8 sec.
With long duration trains the process has, for some unknown reason, slowed down. Various theories have been proposed but they all have their flaws. It seems possible, however, that the processes involved in sustaining long duration trains may be similar to those that produce ball lightning or kugelblitz.
Copyright 1996 Philip M. Bagnall