Canada and the World
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19 November 2010
Moon of Saturn Has Salt Water
Space probe finds evidence of water on Enceladus
As scientists examine more of the solar system they are finding water where none was thought to exist before.
In 1997, the Cassini space probe was launched from Earth with the task of studying the elaborate ring system that surrounds Saturn. Cassini has also been looking at the planet’s moons of which 53 have been found and named.
Facts about Enceladus
Enceladus is a small moon, about 505 kilometres in diameter inside Saturn’s E ring – that’s the outermost of the eight rings that surround the planet.
The BBC’s Science and Nature website describes Enceladus as “The shiniest place in the solar system,” because it is covered with snowy water ice that “reflects virtually 100 percent of the light that falls upon it.”
Cassini Probe Beams back Data
In 1981, the Voyager I spacecraft did a fly past of Enceladus and revealed that plumes of vapour were coming off the moon’s South Pole (below).
NASA
Astronomers did not know at the time what this exhaust was made of. Now they do; it’s water.
The Cassini probe answered the question. A video at NASA’s Jet Propulsion Laboratory points out that in 2005 Cassini revealed “a hot spot at Enceladus’s South Pole…What should have been a geologically dead world appears to be active. This mysterious hot zone is the source of Enceladus’s most striking feature; towering plumes of ice particles and water vapour erupt like geysers…and extend hundreds of miles into space.”
These jets of ice particles come out of surface cracks that have been called “tiger stripes” because they resemble the marking on the big cats.
Does Enceladus Have an Underground Sea?
Writing in Time Magazine (June 2009), Jeffrey Kluger says the ice particles the Cassini probe collected have taken years to analyze, but it has been worth the wait.
“Not only is the ice made of ordinary water, but it’s salt water... ‘Our measurements imply that besides table salt, the grains also contain carbonates like soda,’ says Frank Postberg, a Cassini scientist working at the Max Planck Institute in Heidelberg, Germany.”
The results of the analysis have been published in Nature (June 2009), suggesting “the possibility of a subsurface ocean…It was not clear, however, whether the liquid is still present today or whether it has frozen.
Possibility of Life on Enceladus
BBC News (June 2009) reported confirmation of liquid water would be “a stunning result. It means the Saturnian satellite may be one of the most promising places in the solar system to search for signs of extraterrestrial life.”
Science reporter Jonathon Amos quotes John Spencer, a Cassini scientist from the
Southwest Research Institute, Boulder, Colorado as saying: “We need three ingredients
for life, as far as we know -
Spencer is quick to point out that doesn’t mean there is life on Enceladus, just that the conditions for it to be present seem to be there.
Sources
“Enceledus.” BBC.
“The Salty Waters of Saturn’s Moon Hint at Life.” Jeffrey Kluger, Time, June 26, 2009.
“Sodium Salts in E-
“ ‘Misty Caverns’ on Enceladus Moon.” Jonathon Amos, BBC News, June 24, 2009.
“Water of Life: A Small World with Huge Potential.” Dr. David Whitehouse, The Independent, September 20, 2010.
© Canada and the World, September 2010
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ENCELADUS NUMBERS
The surface temperature is -
The moon is slightly egg shaped, its width differs from its height by about ten km;
It cannot be seen with the naked eye from Earth;
It takes 1.37 Earth days to rotate;
Distance from Saturn is 238,020 km;
It was discovered in 1789 by Sir William Herschel.
Space scientist Dr. David Whitehouse writes in The Independent (September 20, 2010) that the most promising place to find extraterrestrial life is in water trapped under icy crusts.
“Only at Enceladus does there seem to be a way to get to such an under-
At their closest point Earth and Saturn are 1.2 billion km apart. Using current technology, it takes three years and two months to travel there.