UCL News


Long trip from Surrey to Saturn almost over

28 June 2004

After a journey of almost 3.5 billion km lasting seven years, scientists will finally get the chance to unpack their toolkits this week and get cracking on unravelling the mysteries of our Solar System's ringed planet.

Cassini-Huygens will be the first spacecraft to orbit Saturn and fly over the rings, and will provide a unique opportunity to learn more about the birth of the Solar System and humankind's origins.

UK scientists have been involved in building instruments for both Cassini (six instruments) and Huygens (two instruments). One of the three sensors used in the Cassini Plasma Spectrometer instrument is an 'electron spectrometer', which was built at UCL's Mullard Space Science Laboratory with help from researchers based at the Rutherford Appleton Laboratory (RAL) and Forsvarets forskningsinstitutt, Norway. The electron spectrometer will reveal new detail about Saturn's magnetic field and the spokes in Saturn's rings.

Dr Andrew Coates, team leader at UCL's Mullard Space Science Laboratory (MSSL) says:

"We are privileged to be part of one of the great exploratory missions of our time. The ringed giant planet, its 31 moons and its enormous magnetic field provide a fascinating laboratory where we can learn more about how the Solar System formed."

On 1 July as the craft flies just 20,000 km above Saturn's swirling clouds, an onboard rocket engine will fire for 96 minutes to slow the spacecraft and capture it into Saturn's orbit. Immediately afterwards, the spacecraft will make unique measurements just above Saturn's rings.

"This is the first major target for us. Conditions in Saturn's rings resemble those in the early Solar System where dust, light and electrons were present. We will be looking for electrical charging effects in the rings," says Dr Coates.

During Cassini's four year tour of discovery the probe will orbit Saturn and conduct close flybys of many of the planet's moons. There will be 45 flybys of Titan, the largest moon, where a dense nitrogen based atmosphere with a hydrocarbon haze shrouds the surface, and many close flybys of smaller, icy moons. Part of MSSL's work will be studying how particles from Titan's atmosphere, and from the icy moons, affect the Saturn magnetosphere.

Titan's surface temperature is -180 degrees C - and hydrocarbon rain may fall into methane/ethane seas. The atmosphere resembles that of the early Earth soon after its formation 4.6 billion years ago. The Huygens probe will be released on Christmas Day; it will plunge through Titan's atmosphere and land on 14 January 2005.

Saturn's giant magnetic field carves out a cocoon in the fast-flowing solar wind, 20 times the size of Earth's magnetosphere. This makes the timescales for movement of the charged particles inside much longer than those at Earth. Information from how Saturn's magnetosphere works will really test theories of our own magnetic environment.

Dr David Linder, project manager at MSSL for the electron spectrometer, says:

"The excitement is really building as we approach Saturn. The instrument is working excellently and our fingers are crossed for going into orbit on 1 July."

Notes to Editors

For further information please contact:

Judith H Moore
Media Relations Manager
University College London
Tel: +44 (0)20 7679 7678
Mobile: +44 (0)77333 07596
Email: judith.moore@ucl.ac.uk

Dr Andrew Coates
Lead co-investigator at MSSL
Tel: +44 1483 204145
Mobile: 07788448318

Dr David Linder
Project Manager at MSSL
Tel: +44 1483 204169