Scientists find hot spot on Saturn's chilly pole
By Michael Kahn
LONDON (Reuters) - Saturn's chilly north pole boasts a hot spot of compressed air, a surprising discovery that could shed light on other planets within our own solar system and beyond, researchers said on Thursday.
Scientists already knew about a hot spot at Saturn's sunny south pole but data from the Cassini spacecraft now shows that the winter pole drenched in darkness also has a hot spot, said Nick Teanby, a planetary scientist, who worked on the study.
"With this Cassini mission we can also see the winter pole, which we are not able to see from Earth because of the tilt of the planet," said Teanby of the University of Oxford. "We didn't expect it to have a hot spot at the north."
The hot spot is essentially a small, narrow region hotter than the gas surrounding it, the international team reported in the journal Science.
Researchers said the southern hot spot was probably formed by the warm rays of the sun but added compressed air descending from the atmosphere best explained the newly-found hot spot on the north pole.
"We think it is due to air descending from higher in the atmosphere to lower in the atmosphere," Teanby said in a telephone interview. "The mass of air heats up as it's compressed -- like air in a bicycle pump."
The researchers were able to gauge different temperatures using the Cassini spacecraft's infrared spectrometer that measures the intensity of radiation emitted from Saturn's atmosphere. Cassini was launched in 1997 to examine Saturn.
Reconstructed images pinpointed the hot spot smack dab in the centre of the planet's north pole vortex, a swirling motion of high speed air traveling around the pole.
"We've managed to probe the top portion of the atmosphere," Teanby said.
The findings may also help scientists better understand other gas planets in the Earth's solar system such as Jupiter, Teanby said.
They also help shed light on the growing number of newly-discovered planets orbiting stars other than our own. So far, there are more than 230 of these known exoplanets.
"If we can gain an understanding of what goes on in the atmosphere, we can apply them to other planets and extra solar planets now being discovered," Teanby said.
(Reporting by Michael Kahn; Editing by Julie Steenhuysen and Richard Williams)