The Drift of Meteor Trails

Abstract

IN the Astronomical Column of NATURE of May 23 there appears a note on the currents in the upper air as revealed by the direction of drift of the streaks left by meteors. Before we can say with certainty, however, that such drift represents movement of the air, we require to know the real nature of a meteor trail. The ordinary view seems to be that the trail is composed of air heated by the meteor in its flight through the atmosphere, the heating being produced not so much by friction as by the compression of the air in front of the meteor. But is it physically possible for a mass of air so heated to retain its heat so as to remain luminous for any length of time? Streaks have been seen which remained luminous for more than two hours, and though this is exceptional, yet any explanation which would account for long-enduring trails would apply also to the more transient kinds. Is it not possible that the trail is an electrical phenomenon akin to an auroral streamer, or to the patches of light seen during an aurora? The movement of both trails and streamers is usually towards the east, but both more rarely move in other directions. The movement in the case of the aurora is presumably due to the passage of electrified particles moving in the earth's magnetic field, and deflected by it. Is it possible that a meteor trail is due to the passage of electricity through rarefied air that may have been ionised by the passage of the meteor?