Science: Growth of a Tail

Last week a new comet hove into naked-eye view—that is, into the view of people with good eyes. Most observers found it better to look at through 8-power binoculars. A faint feather, the comet is crawling down the western sky, after dusk, toward the constellation of the Eagle (Aquila). It will get brighter this week and next. Toward the middle of January, if it develops as astronomers hope, Cunningham's comet should be the brightest since Halley's great comet of 1910.

Discovered on photographic plates last September by Leland Cunningham of Harvard Observatory, the comet last week was about 100,000,000 miles from earth,...