Sights and sounds of Titan

DARMSTADT, Germany – Titan’s surface appears to be a pale-orange landscape with a thin crust that gives Saturn’s largest moon a squishy consistency, scientists said Saturday after refining images from the planet’s surface.

After working through the night on data relayed by the probe, scientists at the European Space Agency were clearly excited about the success of the mission, which already confirms some long-held theories about Titan and provided a few surprises.

‘I have to say I was blown away by what I saw yesterday,’ lead scientist David Southwood said at the agency’s headquarters in Darmstadt. ‘It was an extraordinary experience to look at some of the stuff.’

Pictures snapped by the probe and a low, rushing sound picked up on Titan by an on-board microphone drew gasps and applause from an audience at mission control Saturday.

With readings from nine instruments carried by the 320-kilogram (705-pound) probe, scientists were building an image of what the far-flung moon could be like on the surface.

Images taken from a height of 18 to 20 kilometers (11 to 12 miles) to right at the surface suggest the presence of liquid, possibly flowing through channels or washing over larger areas, said Marty Tomasko, an expert at the University of Arizona.

‘It is almost impossible to resist speculating that the flat, dark material is some kind of drainage channel, that we are seeing some kind of a shoreline,’ he said.

‘We don’t know if it still has liquid in it.’

A thick layer of cloud or fog that obscures the planet from outside view was found to be hanging at about 20 kilometers (12 miles) from the surface, but absent closer to the ground.

Another project scientist, Shushiel Atreya, said the clouds are most likely made of methane, and he theorized that the dark spots on the surface could also be methane.

‘Presumably there is a reservoir of methane on the surface,’ Atreya said.

The surface itself appears to be ‘material which might have a thin crust followed by a region of relative uniform consistency,’ said John Zarnecki, in charge of instruments analyzing Titan’s surface.

‘The closest analogues are wet sand or clay,’ he said.

A boom mike extended from Huygens after landing revealed a loud, rushing sound. Mission scientists did not immediately say what it might mean.

Titan is the first moon other than the Earth’s to be explored. Scientists think its atmosphere is similar to that of the early Earth and studying it could provide clues to how life began on our planet.

Yet there also was a setback after Huygens’ seven-year trip through space: One of the probe’s two data streams failed to download, meaning it will be some time before data on wind speed in Titan’s atmosphere can be pieced together.

But the sounds suggested blowing and other instruments detected surface winds of about 25 kilometers per hour (16 miles per hour).

The missing data stream robbed scientists of nearly half the hoped-for images, but with about 350 to study there still was ample data to analyze. The ESA was investigating the failure of the second data channel, Southwood said.

Except for the transmission glitch, all instruments on the US$3.3 billion Cassini-Huygens mission to explore Saturn and its moons were working.

‘The instruments performed brilliantly,’ Zarnecki said. ‘We can’t find a single missing data frame. The link and the quality of the data was absolutely superb.’

The probe is sending data to NASA’s Cassini mother ship above Saturn, which relays them to the ESA by way of NASA. The mission was launched in 1997 from Cape Canaveral, Florida – a joint effort by NASA, ESA and the Italian space agency. It is named for 17th-century Saturn observers Jean Dominique Cassini and Christiaan Huygens.

Piecing together a detailed picture of Titan will take years, Southwood said.

‘As long as there are scientists who keep doing science, they will be using this information,’ he said.

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