Possible Lake Revealed in Titan Images
New images and data from the Huygens space probe of Saturn’s frigid moon Titan released Saturday show a Dreamsicle-orange sky, a spongy surface like wet sand and a possible shoreline of a past or present lake.
What is creating these strange phenomena may take weeks, months or even years to understand. But the new information does nothing to dispel one leading theory that the hubcap-shaped probe landed on a frozen flood plain leading to a possible methane lake.
“I was blown away by what I saw,” said David Southwood, director of science programs for the European Space Agency, at a news conference from mission control in Darmstadt, Germany.
Southwood briefly choked up describing the bounty of data streaming to Earth from a billion miles away. Titan is the most remote world visited by a spacecraft.
The joy was restrained by one mechanical problem: Because of a programming error -- either on the European-built Huygens lander or the American Cassini spacecraft, which carried Huygens as a hitchhiker on its seven-year journey through space -- an experiment to measure wind speed on the moon failed. ESA said the information would be retrieved through backup systems.
“There was a blemish,” Southwood said. “We’re human.”
Cassini and Huygens were designed to plumb questions that have intrigued space scientists since Voyager 1 flew by Titan 25 years ago and discovered it had a thick, smog-like atmosphere -- so far a unique feature in the solar system.
The major components of Titan’s atmosphere -- methane and nitrogen -- make it a kind of cold storage version of the Earth before life formed.
The $3.3-billion Cassini-Huygens mission was launched from Cape Canaveral on Oct. 15, 1997. The joint mission reached Saturn in June of last year. Cassini released Huygens on Christmas Eve to fly solo to Titan.
As the landing date approached, some European scientists were at pains to play down expectations for Huygens. They would be happy, they said, if they got pictures from its parachute descent through the atmosphere. Anything they got from the ground would be gravy, they said.
Instead, information poured in from the surface of the moon for 70 minutes.
“We have received a very good data set. It will allow us to achieve all our objectives,” said Jean-Pierre Lebreton, the mission manager for ESA.
“We can now start to see a clear picture of Titan emerging.”
That picture includes the best information yet on what the surface is made of.
According to data from Huygens, the 705-pound probe sank about 6 inches into the surface when it hit at about 10 mph.
Comparing that figure with laboratory studies, scientists concluded the surface had a thin crust and a spongy material under it like wet sand or clay.
One researcher compared it to creme brulee.
None of the liquid on the surface could be water, because it is far too cold for water to exist in a liquid state. The probe’s onboard gauges showed the surface temperature to be minus 290 degrees Fahrenheit.
New images also revealed surface features that one scientist said appeared to be a shoreline with a series of drainage channels above it.
Below is a wide, dark flat area that some have speculated could be a lake of methane or ethane.
During its descent, the probe was ordered to turn on a light to illuminate the surface. The camera picked up a reflection off the dark mass, but Martin Tomasko, a member of the Huygens team in Germany, said it was too soon to say whether that proved the presence of liquid.
“We don’t know if there is liquid in [the dark lakebed] or if it drained into the surface,” said Tomasko, a researcher at the University of Arizona.
Huygens found one strong hint of a ground source of methane: The concentration of methane in the atmosphere was much higher at the surface than at high altitude.
ESA released the first color picture from Huygens. It showed an orange sky and fist-sized blocks of ice.
Scientists also picked up sounds from Titan using an onboard microphone.
One soundtrack revealed a roaring noise, like an engine, while another had a whooshing sound like wind.
“You are all invited to a dance party on Titan,” one scientist quipped.
