9 March 2005
Mathematician Dr Andrew Prentice believes he is one step closer to unlocking the secrets of the solar system after successfully predicting the watery make-up of Saturn's second smallest moon, Enceladus.
In a paper published last month, Dr Prentice said 90 per of Enceladus was frozen water (ice) and 10 per cent rock. The watery composition was confirmed when NASA's Cassini spacecraft came within 1180 km of Enceladus late last month.
Because Enceladus appeared melted, most scientists expected the moon would contain ammonia ice and other easy-melting ammonia compounds, Dr Prentice said
"With the use of infrared mapping Cassini showed the moon's surface was made of only pure water ice, no other compounds were detected," he said.
Dr Prentice theorised during the creation of Saturn and its moons the atmosphere was far too warm for anything other than water and rock to condense in the orbit of Enceladus.
He is now waiting to find out whether Cassini can detect the presence of a rocky core at the centre of Enceladus, which he said should make up 10 per cent of the moon's mass.
He has predicted an average density of 1.0 for the moon, making Enceladus as dense as liquid water. NASA has forecast a density of 1.8.
"If my predictions of Enceladus' density are close to the mark it will be like finding the long lost diamond after more than 35 years work," he said.
For further information contact Dr Andrew Prentice on +61 3 9905 4499 or Ms Ingrid Sanders in Media Communications on +61 3 9905 9201 or 0437 458 457.
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