Saturn's youthful appearance explained

Apr 30, 2013
Saturn. Photo: NASA

(Phys.org) —As planets age they become darker and cooler. Saturn however is much brighter than expected for a planet of its age - a question that has puzzled scientists since the late sixties. New research published in the journal Nature Geoscience has revealed how Saturn keeps itself looking young and hot.

Researchers from the University of Exeter and the Ecole Normale Supérieure de Lyon found that layers of gas, generated by physical instability deep within the giant planet, prevent heat from escaping and have resulted in Saturn failing to cool down at the expected rate.

Professor Gilles Chabrier from Physics & Astronomy at the University of Exeter said: "Scientists have been wondering for years if Saturn was using an additional source of energy to look so bright but instead our calculations show that Saturn appears young because it can't cool down. Instead of heat being transported throughout the planet by large scale (convective) motions, as previously thought, it must be partly transferred by diffusion across different layers of gas inside Saturn. These separate layers effectively insulate the planet and prevent heat from radiating out efficiently. This keeps Saturn warm and bright."

Characterised by its distinctive rings, Saturn is one of the largest planets in our Solar System, second only in size to massive Jupiter. It is primarily made of hydrogen and helium and its excessive brightness has previously been attributed to helium rains, the result of helium failing to mix with Saturn's hydrogen rich atmosphere.

Layered convection, like that recently discovered in , has been observed in the Earth's oceans where warm, salty water lies beneath cool and less salty water. The denser, prevents vertical currents forming between the different layers and so heat cannot be transported efficiently upwards.

These findings suggest that the interior structure, composition and thermal evolution of giant in our Solar System, and beyond, may be much more complex than previously thought.

Explore further: China to send orbiter to moon and back

More information: www.nature.com/ngeo/journal/v6… 5/full/ngeo1791.html

Related Stories

In the shadows of Saturn's rings

Jun 20, 2012

(Phys.org) -- Titan appears to be strung like a bead on Saturn’s rings, which cast shadows onto the southern hemisphere of the gas giant in this beautiful image from Cassini.   Faint but exquisi ...

Evaluating the energy balance of Saturn's moon Titan

Jan 02, 2012

To understand the weather and climate on Earth as well as on other planets and their moons, scientists need to know the global energy balance, the balance between energy coming in from solar radiation and thermal energy radiated ...

Recommended for you

China to send orbiter to moon and back

58 minutes ago

China will launch its latest lunar orbiter in the coming days, state media said Wednesday, in its first attempt to send a spacecraft around the moon and back to Earth.

NASA Webb's heart survives deep freeze test

10 hours ago

After 116 days of being subjected to extremely frigid temperatures like that in space, the heart of the James Webb Space Telescope, the Integrated Science Instrument Module (ISIM) and its sensitive instruments, ...

Cosmic rays threaten future deep-space astronaut missions

15 hours ago

Crewed missions to Mars remain an essential goal for NASA, but scientists are only now beginning to understand and characterize the radiation hazards that could make such ventures risky, concludes a new paper ...

MAVEN studies passing comet and its effects

17 hours ago

NASA's newest orbiter at Mars, MAVEN, took precautions to avoid harm from a dust-spewing comet that flew near Mars today and is studying the flyby's effects on the Red Planet's atmosphere.

How to safely enjoy the October 23 partial solar eclipse

18 hours ago

2014 – a year rich in eclipses. The Moon dutifully slid into Earth's shadow in April and October gifting us with two total lunars. Now it's the Sun's turn. This Thursday October 23 skywatchers across much ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

katesisco
1 / 5 (2) May 01, 2013
Convection not in one huge cell thousands of miles deep but within layers as in our Sol?