"Nobody in their wildest imaginations ever dreamed of finding such features in the rings around Saturn," Allan F. Cook, associate of the Harvard College Observatory, said yesterday of the hundreds of unique ringlets recently discovered within Saturn's rings by researchers at the Jet Propulsion Laboratory in Pasadena, Calif.

The details of the ringlets estimated to number 500 to 1000 are interesting, but not yet understood John C. Pearl of the Goddard Space Flight Center and co-investigator for the Voyager infrard experiment, said yesterday.

Voyager I's latest data transmissions also enabled the Pasadena scientists to determine that Titan, Saturn's largest moon, has a dense, extremely cold atmosphere, composed primarily of nitrogen. which might have allowed Titan to follow a development path similar to the earth's.

Transmissions from the spacecraft to earth have prompted scientists to conclude that Titan is the only known moon in the solar system with an atmosphere.

Von R. Eshleman, professor of Astronomy at Stanford University and one of the Voyager scientists, said yesterday. "We expect Titan's atmosphere to be almost three times as thick as the earth's.

Chunky

Three separate experiments using Voyager I data indicate that Titan's atmosphere is almost 90 per cent nitrogen. Eshleman hypothesized that since the earth's atmosphere is 78 per cent nitrogen, the two bodies may have similar origins and development paths.

The temperature, however, in the clouds closest to Titan's surface is almost -333 degrees fahrenheit; it is possible that the moon's development may have stagnated in this "deep freeze," Eshleman added.