Plumes of material erupt from the long 'tiger stripe' fractures on the south pole of one of Saturn's moons, Enceladus.
Credit: NASA
SYDNEY: Saturn's icy moon Enceladus harbours a salty ocean under the surface, astronomers have discovered, making it a favourable place for alien life.
Two studies released in Nature today looked for evidence for salt in the particles ejected from a plume of water vapour and ice crystals stemming from Enceladus' south pole. The plume was first discovered by NASA's Cassini spacecraft in November 2005.
The first study, led by Frank Postberg from the Max Planck Institute for Nuclear Physics in Heidelberg, Germany, used Cassini's Cosmic Dust Analyser to check the composition of ice and dust particles. The particles had been spread through Saturn's outermost 'E' ring, where Enceladus orbits, by the plume.
Ocean beneath the ice
The team found that most grains were pure water ice, about 6% were very salty and mixed with carbonates such as soda, in concentrations that fit with the predicted composition of an Enceladus ocean.
The salt is thought to have been washed out of an inner rocky core by a body of water locked beneath Enceladus's icy crust and ejected in plumes thousands of kilometres into space. It provides the first direct confirmation of the presence of water.
"We believe that the salty minerals deep inside Enceladus washed out from rock at the bottom of a liquid layer," said Postberg.
"If the liquid source is an ocean, that, coupled with the heat measured near the moon's South Pole and the organic compounds found within the plumes, could provide a suitable environment on Enceladus for the formation of life precursors."
'Tiger stripes' also point to ocean
Enceladus is a small, icy moon with a radius of just 247 km and a surface temperature of minus 201 degrees Celcius. Astronomers previously theorised that features on Enceladus, including the plumes and dark, 'tiger stripes' of fresh ice, were consistent with the presence of a subsurface ocean beneath the ice. What wasn't clear was whether the water was still present today, and in what form.
The body of water can't be directly below the surface, however, because there isn't enough sodium in the plume itself, discovered Nicholas Schneider, from the University of Colorado, in Boulder. Along with colleagues, he published the second study on Enceladus' ocean, also in Nature.
Do any moon's spin ?
Our's doesn't, we all know that, and I can't see why any should, but it intrigues me and I'd love an answer if there is one?
The Moon does spin
If I remember correctly, the Moon does spin on an axis. It takes 28 Earth days to finish one Lunar day though. So because the time it takes for the Moon to orbit and and turn, thats why we only ever see one side.
planets and moons
I may be a ?? year old kid! but i know alot about space, you see, the earths axis is 24.3 degress clockwise so really were diagonal!!!!, the moon does spin, so fast that we only see one side of the moon (the 'sea of tranquility')
but its actually 27.3 earth days it takes for a full lunar thing so ha!, venus is 425 degress celcious hot hot!
mercury is so far the fastest planet in our solar system,
earth supports life (obviously!) mars is actually rusty because of the carbonate and sulphur in its core getting burned, saturn is a gas planet, i found out by a scientist that at the bottom of one of saturns moons is water! which supports life!! (fish life! this is true), jupiter is bigger than saturn and the 'red spot' is actually a 1,030km storm that can fit 3 earths inside! uranus is pure gas, sadly thats all i know so far about uranus, neptune isnt actually water, its clouds full of carbon dioxide and methane and more! but its core has loads of water in it (and ice and iron) and NOT last of all, pluto! pluto is so small it has an irregular orbit so it takes over the orbit of neptune so neptune is the last haha, but it takes 5 years for pluto to get in front of neptune and 6 or 7 years to get behind it again!!!!!!!!!
thats all
~anonimous