Cassini: what we'll miss | University of Oxford
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Cassini: what we'll miss

Pete Wilton

Today's Times carries a letter from scientists working on the Cassini mission.

Cassini, you may remember, is one of the projects that STFC has chosen to withdraw from as part of a cost-cutting exercise. It's also a project that Oxford scientists have made a major contribution to.

Simon Calcutt, from Oxford University's Department of Physics, is one of the letter's signatories who write: 'the UK Cassini teams that discovered the ice volcanoes on the Saturnian moon Enceladus, the rich chemistry of the prebiotic atmosphere of Titan, and the mechanism of Saturn’s auroras now face imminent disbandment, abandoning still-functioning UK-led instruments in orbit around the planet.'

Unless other funding sources can be found the decision signals a sad end to what has been a major UK science success story. Both Mark Henderson in The Times and Jonathan Amos on BBC Online mull over the consequences and how it might impact on UK involvement in future missions and the next generation of British space scientists.

Whatever you think about how spending on space science should be prioritised it's worth noting just what a phenomenal success Cassini has been so far, even just from the Oxford perspective:

Back in January 2004 Oxford University scientists working on data from Cassini identified a jet stream in Jupiter's atmosphere that resembles similar weather features found on Earth.

They were part of the team behind the Infrared Spectrometer that, in July 2004, was sent to scrutinise Saturn, its rings and moons, as the spacecraft hurtled by the giant planet.

Years of data crunching and modelling saw them make a series of major discoveries, highlights include:

Finding a hexagon-shaped 'hot spot' in the middle of Saturn's chilly north pole: the result of air moving towards the pole, being compressed and heated up as it descends over the poles into the depths of Saturn. Reported in Science, this gave clues to the atmospheric formations found on Jupiter, Neptune and Mars.

New observations of Saturn showed that its southern polar vortex is similar to hurricanes found on Earth. Both have cyclonic circulation, a warm central 'eye' region surrounded by a ring of high clouds - the eye wall - and convective clouds outside the eye. These 'saturnicanes' also resembled polar vortices on Venus, giving further weight to the idea that understanding the weather on one planet call tell us a lot about weather on others (including our own).

Only last year, Oxford scientists using Cassini reported in Nature that they had come up with a new way of detecting how fast large gaseous planets are rotating: a method which suggests Saturn’s day lasts 10 hours, 34 minutes and 13 seconds – over five minutes shorter than previous estimates based on the planet’s magnetic fields.

These are just a few examples and, according to NASA, in Cassini's new extended mission there should be many more exciting discoveries to come:

'The extension presents a unique opportunity to follow seasonal changes of an outer planet system all the way from its winter to its summer... The mission extension also will allow scientists to continue observations of Saturn's rings and the magnetic bubble around the planet known as the magnetosphere. The spacecraft will make repeated dives between Saturn and its rings to obtain in depth knowledge of the gas giant. During these dives, the spacecraft will study the internal structure of Saturn, its magnetic fluctuations and ring mass.'

It's a shame that it looks like researchers from Oxford and around the UK will only be able to cheer the plucky old probe on from the sidelines instead of being at the heart of a truly unique space odyssey.