Eos, Transactions American Geophysical Union

Dayglow holes may reveal comet influx



Two controversial papers in the April issue of Geophysical Research Letters by a group from the University of Iowa offer a new picture of the earth's upper atmosphere and the source of water on the earth and other planets. Louis A. Frank and colleagues John B. Sigwarth and John D. Craven proposed that the earth may be seeing an influx of as many as 20 small comets per minute, each weighing perhaps 100 tons. Since comets contain a great deal of water ice, such a phenomenon could add significant amounts of water to the earth's atmosphere in a short time.