Titan’s First Close-Up

Cassini-Huygens, the joint NASA/ESA/ASI space mission has successfully made a close encounter with Saturn’s moon, Titan. This was confirmed in the early hours of this morning as the first information and pictures were beamed back via NASA’s Deep Space Network tracking station in Madrid, Spain. As anticipated, the spacecraft came within 1,200 kilometres (750 miles) of Titan’s surface.

At the time, Cassini was about 1.3 billion kilometres (826 million miles) from Earth. Numerous images, perhaps as many as 500, were taken by the visible light camera and were being transmitted back to Earth. It takes 1 hour and 14 minutes for the images to travel from the spacecraft to Earth. The downlink of data will continue through the night into the early morning hours. Cassini project engineers will continue to keep a close watch on a rainstorm in Spain, which may interrupt the flow of data from the spacecraft.

Professor Carl Murray from Queen Mary, University of London, a member of the Cassini Imaging Science Subsystem team, has been taking a look at the first images, “Titan’s veil has been lifted yet again and we have been treated to a spectacular array of images from this bizarre moon. The return of this data from such a peculiar and distant world is another remarkable success for Cassini. When the images are combined with data from the other instruments on Cassini we will have a much more complete understanding of what the Huygens probe can expect when it lands in January.”

The flyby was by far the closest any spacecraft has ever come to Titan, the largest moon of Saturn, perpetually drenched in a thick blanket of smog. Titan is a prime target of the Cassini-Huygens mission because it is the only moon in our solar system with an atmosphere. It is a cosmic time capsule that offers a look back in time to see what Earth might have been like before the appearance of life.

Mark Leese, is a member of the Huygens team at the Open University, who are involved in the Science Surface Package (SSP) and the Huygens Atmospheric Instrument (HASI). “The Open University Huygens team are looking forward to what these images and other data may tell us about the surface of Titan, in anticipation of the Huygens mission on January 14th 2005. Then we hope that the UK built Surface Science Package will send back the first measurements from the surface of Titan.”

He adds, “The combination of images, spectrometer measurements and RADAR data from this close flyby should help to prepare us for the mission ahead. In addition, Cassini’s measurements of the atmosphere should confirm that the Titan atmosphere model used to design the probe entry system is correct.”

The Huygens probe, built and operated by the European Space Agency, is attached to Cassini; its release is planned on Christmas Day. It will descend through Titan’s opaque atmosphere on January 14, 2005, to collect data and touch down on the surface.

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).