Paris: A day on Saturn is pretty short, and
it just got shorter.
The time it takes the be-ringed behemoth to complete a
spin on its axis has just been calculated by astrophysicists
at 10 hours, 34 minutes and 13 seconds, more than five minutes
shorter than previous estimates.
A planet comprising clouds of gas driven by layers of
mighty jet streams, Saturn has no lasting visual landmarks as a
rocky planet does, and this lack makes it hard to measure the
As a result, astronomers have traditionally based their
calculations on Saturn`s magnetic field. But this signal can
fluctuate and does not accurately measure how fast the
planet`s deep interior is rotating.
An international team led by scientists from Oxford
University and the University of Louisville, Kentucky, used a
different technique based on infrared images taken by the US
spacecraft Cassini orbiting Saturn.
Their paper is released today by Nature, the
British-based science journal.
"We realised that we could combine information on what
was visible on the surface of Saturn with Cassini`s infrared
data about the planet`s deep interior and build a
three-dimensional map of Saturn`s winds," said Oxford
professor Peter Read.