The answer to this fascinating question may be found on
Titan, Saturn’s largest moon. University of Southampton
scientist Professor Tim Leighton has speculated how the sound
of splashing liquid in deep space might differ to that heard
on Earth - and it’s possible that his theory could be proved
later this year by NASA’s Cassini mission to Saturn. In the
meantime, he has recreated the sound he believes it makes and
put it on the Internet.
On Thursday 1 July 2004,
NASA’s Cassini space craft will go into orbit around Saturn
where it will study the planet, its moons and rings for four
years. However, in Professor Leighton’s view, possibly the
most interesting aspect of the Cassini mission, is the
European Space Agency’s probe Huygens, which will study Titan.
After a seven-year journey strapped to the side of Cassini,
the probe will separate from it on Christmas Day 2004 and
coast for 20 days before parachuting through the thick
atmosphere to become the first man-made object to land on the
moon of another planet on 14 January 2005.
thick smog has prevented earlier spacecraft photographing its
surface, but there are suggestions that the moon may be home
to seas and streams made, not of water, but of liquid ethane.
The main focus of Huygens’ mission is sampling the smog-laden
atmosphere, but three minutes of battery time will be used for
investigations immediately after landing. Although the probe’s
microphone is on board primarily to monitor atmospheric
buffering, Professor Leighton of the University’s Institute
for Sound and Vibration Research, has suggested that, were the
microphone to detect a splash-down as opposed to a crunch on
landing, the question of what a splash in space might sound
like would be answered.
Professor Leighton, who has
speculated for several years on sounds in space, explains: ’I
began asking whether the noise of splashes which is so
familiar to us on Earth would be recognisable in a sea of
liquid ethane at a temperature of 180 degrees below zero.
NASA’s specially-commissioned painting of a waterfall -
actually a methane fall - on Titan inspired me to attempt to
predict how it would sound. I set up the equations and
measured the sound of a small waterfall in nearby Romsey. My
colleague Dr Paul White then processed the signal to obtain
what we believe would be the sound of a methane fall on Titan.
’Given that the last decade has seen an explosion in
the amount we can learn about the oceans simply by listening
to them, from storms to seabed properties to coastal erosion,
acoustics represent a potentially exciting and comparatively
low-cost method of space exploration.’
Leighton outlines his ideas for the role of acoustics in space
exploration in an article entitled ’The Sound of Titan’ to be
published in the July/August edition of Acoustics Bulletin.
The sound of the methane fall as calculated by Professor
Leighton and Dr Paul White can be heard at