Meteor Trail

meteor trail

[′mēd·ē·ər ‚trāl]
(geophysics)

Meteor Trail

 

the train remaining in the atmosphere after the passage of a meteor. There are two types of meteor trails: dust trails and gas, or ionized, trails. Dust trails are formed only by bright bolides at heights of 25–80 km as a result of the condensation of vapors of meteoric material in the head and train of the bolide and the solidification of droplets of molten material blown off the meteor’s surface. At twilight, the luminosity of dust trails is the result of the scattering of sunlight by minute particles, measuring less than 10 ~4 cm in diameter. Dust trails are visible for periods of up to several hours. The luminosity of ionized trails results from recombination processes; the spectra of these trails show lines of Mg, Na, Ca, Fe, and other elements. Ionized trails are formed by all meteors, but only those of bright meteors can be observed by the naked eye. They are visible for periods ranging from fractions of a second to several minutes. Because radio waves are reflected by ionized trails, such trails can be observed by radar.

Initially, the meteor trail is straight and thin; however, wind and diffusion soon cause it to curve and broaden. Optical and radar observations of meteor trails are one of the principal methods of studying the circulation and turbulence of the earth’s atmosphere at heights of 80–110 km.

V. N. LEBEDINETS

References in periodicals archive ?
There are six steps in the sweep, each illuminating a different portion of the meteor trail.
That bit of matter makes a meteor trail, glowing brightly for a moment, perhaps to the accompaniment of expressions of delight by onlookers below.
If we assume that the meteor first became visible at a height of 110km we find that the distance to the positions on the ground under the start and end points of the trajectory are 56 and 33km respectively, the length of the meteor trail is 51km and the end height is 70km.
became the first to send a spoken message via meteor trail.
He realised that time spent recording the path of each meteor trail could be drastically reduced if, rather than drawing a line on a star chart, the observer committed to memory the designations of all of the brightest 3,000 naked-eye stars and recorded the path simply by naming naked-eye stars close to its start and end points in a notebook.
This large number of reception paths reduces meteor trail orientation and polarisation effects, and gives a higher count-rate than a single transmitter/ receiver path, as might be used in standard forward-scatter observations.
Meteor trails, satellites, the International Space Station, noctilucent clouds and the northern lights can all be photographed with long exposure photography.
Observations of the Martian atmosphere are designed to check for possible meteor trails, changes in distribution of neutral and charged particles, and effects of the comet on air temperature and clouds.
Astronomer Masanori Iye of the National Observatory of Japan blames the blurry appearance of meteor trails at about 100 kilometers altitude on the fact that they were photographed with telescopes focused at infinity ("Out-of-focus find," SN: 9/29/07, p.
If you trace all the meteor trails backwards, they meet at a point just above Leo in the north-east.
Nick James and Peter Meadows reported most useful series of automated video and still observations for both the Geminids and Quadrantids, and good sets of visual watches were secured by Richard Fleet, observing from Wilcot near Pewsey in Wiltshire, who also managed to image a significant number of bright meteor trails during both showers.
This page provides links to pictures of meteor trails, including those of the 1976 event given here.