The NASA/ESA/ASI Cassini Huygens mission to Saturn, which has already delivered stunning images and data of the ringed planet following insertion into the Saturnian system on 1st July this year, is poised to enter a crucial stage in its voyage of scientific discovery. In the early hours of Christmas morning [25th December] the Huygens probe will separate from the orbiter, its home for the last seven years, to parachute down through the nitrogen-rich atmosphere of Saturn's largest moon, Titan, where it will come to rest - although the exact nature of its final resting place remains a mystery. Scientists speculate that Huygens may find lakes or even oceans of a mixture of liquid ethane, methane and nitrogen.
Prof. John Zarnecki of the Open University, principal scientist for the Science Surface Package, the first instruments to make contact with Titan's terra firma is open minded, "It's a distinct possibility that I could be the very first scientist to carry out oceanography on an outer planet of the solar system.
But equally the probe could land with a thud on hard ground or squelch into a morass of extraterrestrial slime - no one knows for sure. In any event, the instruments onboard have been designed to handle a range of possibilities. Let's just say that after a seven year voyage and twenty years of planning, design and build I will be extremely pleased to land, whatever the surface".
Following separation from the mothership Huygens will coast unguided and unpowered for 20 days towards Titan where it will arrive on the 14th January  to begin its entry and descent to the moon's surface. Travelling at Mach 2 [1522 mph] the probe will enter Titan's atmosphere at an altitude of 1270km [789 miles] and decelerate to an impact speed of 5 meters per second - the equivalent to jumping from a chair onto the ground.
Commenting on the mission Prof. Ian Halliday, Chief Executive of the Particle Physics and Astronomy Research Council [PPARC] that funds UK involvement in the joint NASA/ESA/ASI project said, "Superlatives can come easy when talking about space missions but this particular voyage of scientific discovery is truly awesome. Huygens will be the furthest man-made object to land on a remote celestial body and whilst the science returns from Titan are eagerly awaited we shouldn't forget that the European Huygens probe is totally controlled by UK developed systems and hardware. At a distance of almost 1.3 billion km [789 million miles] that's quite a feat".
Prof. Halliday added," Titan is a mysterious place and raises many scientific questions. Its thick atmosphere is mostly nitrogen, but there are also methane and many other organic compounds. Some of them would be signs of life if they were on our planet. Organic compounds form when sunlight destroys methane. If sunlight is continuously destroying methane on Titan, how is methane getting into the atmosphere?"
Notes for Editors
A Mission timeline, outlining critical steps is available at http://www.pparc.ac.uk/Nw/Huygens_timeline.asp
A Media programme outlining briefings and data releases is at http://www.pparc.ac.uk/Nw/media_timeline.asp
Images to accompany this release are at http://www.pparc.ac.uk/Nw/Cassini_images.asp and on the NASA/ESA websites - see below for details.
Peter Barratt - PPARC Press Office
Tel: 01793 442025. Mobile: 0787 9602899
Gill Ormrod - PPARC Press Office
Tel: 01793 442012 Mobile: 0781 8013509.
Franco Bonacina - ESA Press Office
Tel: +31 1 5369 7155
Don Savage - NASA HQ Press Office
Tel: +1 202 358 1727
Carolina Martinez - JPL Press Office
Tel: +1 818 354 9382
UK Science and Industrial Involvement Contacts - for UK science and industry are available at http://www.pparc.ac.uk/Nw/UK_Science_Contacts.asp UK scientists are playing significant roles in the Cassini Huygens mission with involvement in 6 of the 12 instruments onboard the Cassini orbiter and 2 of the 6 instruments on the Huygens probe. The UK has the lead role in the magnetometer instrument on Cassini (Imperial College) and the Surface Science Package on Huygens (Open University). UK industry had developed many of the key systems for the Huygens probe, including the flight software (LogicaCMG) and parachutes (Martin Baker). These mission critical systems need to perform reliably in some of the most challenging and remote environments ever attempted by a man made object. LogicaCMG software onboard the probe will be responsible for deploying the parachutes, separating the front and back shield with precise timings to achieve the required descent profile; reducing the velocity of Huygens before commencing the science experiments, and managing communications back to Cassini.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency [ESA] and the Italian Space Agency [ASI].
The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL.
The Particle Physics and Astronomy Research Council (PPARC) is the UK's strategic science investment agency. It funds research, education and public understanding in four broad areas of science - particle physics, astronomy, cosmology and space science.
PPARC is government funded and provides research grants and studentships to scientists in British universities, gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Organisation for Nuclear Research, CERN, the European Space Agency and the European Southern Observatory. It also contributes money for the UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility.