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Titan Images Seem To Hold Water

Probe Suggests Moon Has Sludgy Surface

By Guy Gugliotta
Washington Post Staff Writer
Sunday, January 16, 2005; Page A03

DARMSTADT, Germany, Jan. 15 -- It is a desperately cold, forbidding landscape, where water ice becomes fist-size chunks of stone, but scientists said Saturday that Saturn's remote moon Titan may have one thing found nowhere else in the solar system besides Earth -- lakes and rivers.

"I'm just staggered by the level of detail," said European Space Agency science chief David Southwood, examining images of Titan captured by the agency's Huygens space probe just a day earlier. "It's the only other place where there might be lakes and rivers -- right now."


An image from the Huygens probe during its descent on Titan shows a boundary between light and dark areas. The white streaks could indicate "ground fog." The probe drifted over a plateau, center, and headed to its landing site, at right. (ESA via AP)

_____A Celebrated Landing_____
Huygens Space Probe Video: Space officials' hopes were buoyed after the probe continued to transmit data well past its scheduled landing time.
_____Cassini-Huygens Sites_____
ESA Cassini-Huygens Mission
NASA's Cassini-Huygens site
_____Seeing Saturn_____
Saturn has reached its closest point to Earth and is shining at its brightest with its rings tilted at 23 degrees, an excellent angle for viewing.
_____From The Post_____
On to a Moon of Saturn -- and the Unknown
Summary: Probe Lands on Titan
From Associated Press at 9:38 AM

THE MISSION: The European Space Agency's Huygens probe entered the atmosphere of Saturn's moon Titan in a mission to provide clues to how life arose on Earth.

THE PLAN: The probe carries instruments to explore what Titan's atmosphere is made of and to find out whether it has cold seas of liquid methane and ethane.

THE BACKERS: The mission, a project of NASA, ESA and the Italian space agency, was launched on Oct. 15, 1997, from Cape Canaveral, Fla., to study Saturn, its spectacular rings and many moons.

Southwood was one of scores of exhausted but exultant scientists who took a first glance at the near-flawless data returned by Huygens as it parachuted 789 miles through Titan's smoggy atmosphere and came to rest on a rock-strewn plain bathed in orange twilight.

All six of Huygens's instruments functioned perfectly, and although a software glitch stymied transmission of data about Titan's winds, 18 Earth-based radio telescopes on four continents were able to eavesdrop on the probe's signals and will collaborate to reproduce the experiment.

As a result, said Huygens project manager Jean-Pierre Lebreton, "we have received a very good data set that will allow us to realize all our goals."

Scientists have long coveted the opportunity to see Titan up close, but until Huygens's spectacular voyage, they have been frustrated by a cloud of methane-laced nitrogen that obscures the moon's surface.

The nitrogen, the hydrocarbons and the presence of water ice have transformed Titan -- the second largest moon in the solar system -- into a cold-storage laboratory mimicking many of the conditions that probably existed on Earth before life evolved.

Forcing Titan to surrender its secrets was a principal goal when NASA and the European and Italian space agencies launched the Cassini-Huygens spacecraft in 1997 on a voyage of exploration to Saturn, its rings and seven of its 33 known moons.

Cassini, with Huygens riding piggyback, went into orbit around Saturn last June 30, and on Christmas Eve sent the 700-pound probe on a three-week transit to Titan that culminated in a two-hour, 27-minute parachute drop to the moon's frigid surface. By early afternoon Friday, Huygens had relayed all of its information to Cassini for retransmission to the European Space Operations Centre in this Frankfurt suburb.

On Saturday, scientists stressed that months or even years will elapse before researchers can thoroughly digest Huygens's mountain of data, but a vague sketch of this remote wilderness began to emerge.

The methane haze, which gives Titan a green-blue cast at higher altitudes, turns the sky bright orange at ground level, spectrographic data taken by Huygens showed. Surface temperatures were 291 degrees below zero Fahrenheit, as predicted, with a low temperature of 333 degrees below zero recorded during the descent.

The imaging team presented its first panoramic view of Titan's surface Saturday, showing a broad expanse of what looked like coastline, crags and sludgy, glacier-like deposits that could pass for a harbor in Earth's polar reaches.

"It's almost impossible to resist the interpretation that this is some kind of drainage channel," imaging team leader Marty Tomasko told reporters, pointing to a fjord-like gorge running through the middle of the picture.

But, he said later, "you have to be careful, because we're biased by the things we see on Earth." The "sea" in the panorama may not be liquid, but instead a mushy hydrocarbon slush the color and consistency of wet clay, he said.


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