Recently the Rosetta spacecraft sent back some rather disturbing images of its target, the almost impossible to pronounce, comet 67P/Churyumov-Gerasimenko. Instead of the nice “potato shape” that was expected, the Open University’s Dr Andrew Morse describes the comet as looking more like a rubber duck.

The European Space Agency has released an animation of the comet based on the latest data sent back by Rosetta. The complex shape of the comet may pose additional challenges for the Philae Lander as it attempts to touchdown on the surface later this year. Professor Ian Wright, in the first edition of “Rosetta News”, is quoted as saying “As for the new shape, it’s awesome and terrifying in equal measure.”

Rosetta was launched on 2 March 2004 from Kourou, French Guiana and is due to arrive at its target on 6 August. It will become the first spacecraft to rendezvous with a comet. Previous missions, such as Giotto, were essentially fly-bys that provided only limited scope for detailed investigation of the comet’s nucleus. So to mark this important event the European Space Agency is planning a full programme of scientific briefings, which will undoubtedly receive wide media coverage.

But this is really just the start of the adventure.

With an average separation of just 25km, the Rosetta orbiter will stay close to Comet 67P/Churyumov-Gerasimenko as it sweeps in towards the Sun making detailed observations of its nucleus. Then in November a small lander known as Philae will be launched from the orbiter and touch down on the surface of the comet. Philae weighs 100 kg and carries a complement of 9 separate experiments designed to study the surface of the comet’s nucleus in unprecedented detail. The lander operations have a nominal lifetime of one week, but if successful should be extended to several months.

As part of the instrument package on Philae a team at the Open University, led by Professor Ian Wright, has designed and built an analysis package known as Ptolemy that will measure the isotopic composition of Hydrogen, Nitrogen, Oxygen and Carbon. Comets are amongst the most primitive bodies in the Solar System and carry a rich complement of organic compounds that may represent the essential building blocks of life. The measurements made by Ptolemy will provide critical information about the origin and evolution of comets.

So Rosetta’s long journey is nearly over and the party is just about to begin.

To find out more about the Rosetta mission visit the Rosetta Blog.

To find out more about the Open University’s Ptolemy instrument visit the Ptolemy Blog.