Scientists thrilled by bird's-eye view of Titan
Jubilant European scientists on Saturday unveiled the secrets of mysterious Titan, a world that has a surface like crÃ¨me brÃ»lée.
British-built instruments carried on Europe’s Huygens probe, which landed on Saturn’s giant moon on Friday, have revealed an alien surface with a thin crust and soft, sticky material underneath.
“The nearest Earth equivalent that we can think of is crÃ¨me brÃ»lée, though of a rather gritty nature—more like sandy crÃ¨me brÃ»lée,” said Andrew Ball, a member of the Open University team that built Huygens’s Surface Science Package (SSP), which has sent back analyses of the landing site.
Ball was speaking on Saturday after he and hundreds of his European colleagues spent a sleepless night analysing data transmitted from Huygens during its four-hour life on Titan.
The mission’s success has raised hopes of understanding the evolution of the solar system and of life on Earth. As Al Diaz, science associate administrator of Nasa—which has collaborated on the Huygens mission—said: “Titan is a time machine that gives us an opportunity to look at conditions that existed on early Earth.”
There were a few glitches, however.
These included the loss of half the 700 images that were to have been beamed back to Earth, a failure that occurred because one of Huygens‘s data channels was not switched on automatically.
The European Space Agency, which built the probe, is to carry out an investigation.
But the loss was a minor one, and European scientists on Saturday hailed the mission as their greatest interplanetary success. Among the sensational information beamed back from this strange, freezing world were images of what seemed to be rocky shorelines lapped by a dark liquid sea.
“We can also see white patches on these dark areas, which may be low fogs of methane,” said Marty Tomasko of Arizona University, a United States collaborator on the European mission. It was an American spaceship, Cassini, that carried the probe from Earth to Saturn.
Scientists at Saturday’s conference were also entranced by the sounds recorded by Huygens as it dropped through Titan’s atmosphere. The noise—like the buzzing of a million bees—brought rapturous applause.
“We have a new techno music,” announced project leader Marcello Fulchignoni.
By contrast, many of the dramatic images sent back from Saturn’s largest moon were received in stunned silence. Because their little probe did not simply plunge straight down through Titan’s atmosphere but swept over dozens of kilometres of the moon’s surface, researchers have been able to piece together a panorama of Titan from a height of about 10km.
Again, what seem to be shorelines and seas of dark liquid dominate the landscape.
“They could be areas of liquid, or they could be areas where liquid has just dried out,” added Tomasko.
If this is crÃ¨me brÃ»lée, then it is a very strange type of dessert. The fist-sized rocks in the foreground, for example, are balls of ice at -180 degrees Celsius. And according to the Open University’s John Zarnecki, who headed the team that designed the SSP, they are resting on beds that have the consistency of wet clay or sand.
Early data suggest Titan’s sticky soil consists of an oily, tarry substance made of hydro-carbons. This was confirmed by researcher Sushil Atreya, whose mass spectrometer detected methane evaporating from Titan’s surface at Huygens‘s landing site. Atreya’s machines also recorded ethane, acetylene and other complex hydrocarbon molecules.
At Saturday’s conference, astronomer Leonid Gurvits announced that 18 radio telescopes on Earth had tracked Huygens during its descent.
“That means we will be able to pinpoint its landing site with an accuracy of about 1km, which is not bad for an object that’s 1,2-billion kilometres away.”
However, if there was one scientist whose mood best summed up the occasion, it was Zarnecki. He has worked on this project for almost 20 years and, although exhausted, was ecstatic about his team’s work.
“It has been an incredible achievement,” he said.
Zarnecki also revealed that he had won his team’s sweepstake, in which each member guessed how long the probe would take to descend.
“It took two hours, 27 minutes and 50 seconds to reach the surface; I was seven seconds out.”
His prize—a bottle of Scotch—was put to good use.
“‘It was consumed by my colleagues at 2.30am, just as we were interpreting Huygens‘s data.”—Guardian Unlimited Â