The international Cassini spacecraft began unveiling Saturn's mysterious sidekick Titan with a stream of increasingly sharp pictures of the surface taken during a flyby within 745 miles of the hazy moon.
CBS News Space Consultant Bill Harwood, who was at the Jet Propulsion Laboratory as the images arrived, says the first pictures back were spectacular.
"There's quite a variety of features on the surface," Harwood reports. "There are very sharp gradations between bright areas and dark areas, but as of yet, they cannot tell whether liquids exist on the surface, which theory says there may be. They don't see impact craters; they do see possible signs of erosion."
JPL scientists were thrilled, but admitted they could only speculate about what they were seeing.
"What we're looking at is the surface of Titan and that's pretty cool because it's never been done before (at such resolution)," said imaging scientist Carolyn Porco. Cassini's previous Titan flyby was at a distance of some 200,000 miles.
Scientists hoped the pictures and instrument data would show whether the hazy hydrocarbon skies of Titan have been concealing oceans or lakes of methane and ethane, which theories say could rain out of its skies.
The Cassini probe could provide an insight as to what may have been occurring on Earth several billion years ago, says Harwood.
"Titan is one of the biggest moons in the solar system. It's bigger than two of its planets, Mercury and Pluto, and of course it's the only one with a thick atmosphere," he said. "That atmosphere has quite a lot of organic compounds in it. [Scientists] believe that the conditions there now on Titan mirror in some respects what conditions must have been on earth back at the very beginning when the Solar System formed."
Mission officials also hoped instruments would reveal new details of its atmospheric density, which would be useful when Cassini launches the European Space Agency's Huygens probe for a descent to Titan's surface in January.
The spacecraft made its closest approach to Titan at 9:45 a.m. PDT Tuesday and began transmitting pictures back to Earth about nine hours later.
Getting pictures from Cassini is just one part of the mission. The scientists will also be looking for radar data.
"The Cassini craft can actually make images of the surface using cloud-piercing radar that should be very sharp and give a lot of insight into topography of the surface, elevations, and what sort of structures may be there," reports Harwood.
Unlike many other bodies in the solar system, Titan did not show any initial evidence of clearly circular features that might be impact craters, such as those that can be easily seen on Earth's moon, Porco said.
"It could be that if there were impact structures they might have been buried in the material that is falling out of the atmosphere and coating the surface," she said.
The $3.3 billion spacecraft was launched in 1997 and flew 2.2 billion miles on a roundabout route to Saturn. NASA said it has worked flawlessly since soaring through a gap in Saturn's shimmering rings to enter orbit.
The mission was funded by NASA, the European Space Agency and the Italian Space Agency.
CBS News Space Consultant William Harwood has covered America's space program full time for nearly 20 years, focusing on space shuttle operations, planetary exploration and astronomy. Based at the Kennedy Space Center in Florida, Harwood provides up-to-the-minute space reports for CBS News and regularly contributes to Spaceflight Now and The Washington Post.