Methane clouds have been sighted on Saturn's largest moon Titan but there has been no evidence for the production of lightning, says study published Wednesday.

A scientist from the Austrian Academy of Sciences, Georg Fischer, and Don Gurnett, his American colleague from the University of lowa, examined data from the US-European spacecraft Cassini, which detects lightning's radio signature during a flyby of Earth, and said there was no obvious evidence of lightning production on Titan.

Titan has its own atmosphere -- "this is an important prerequisite for the emergence of life" -- Fischer said.

Despite repeated infrared absorption of recognizable concoctive methane clouds that change within hours, electrical discharges could not be detected, said Fischer.

He said he and his colleague have come to the conclusion that lightning is either very rare or simply not on Titan.

The scientists' findings were published in the science journal Geophysical Research Letters.