NOVEMBER 17, 1980. Voyager 1 is on its way to a rendezvous a decade from now with the outer edges of the solar system, where the solar wind’s influence ends. “We’ve had a great ride,” says chief scientist Ed Stone. “It’s been so smooth, it’s hard to appreciate how much work went into it. Building the spacecraft was the work of thousands; flying it was the work of hundreds.” Planning where Voyager would fly took years of studying just where each moon and planet would be when. Ten thou¬sand different trajectories were considered during the research period.
“We are in the rush of discovery,” con¬cludes Stone. “Next comes the understand¬ing, which may take years.”
DECEMBER 12, 1980. A month has passed. Titan becomes easier to un¬derstand. Mission radio scientist Von Eshleman announces in San Francisco that his team’s experiment now shows Titan’s atmosphere to be 4.6 times denser than Earth’s, and its surface to be 93° Kelvin, or minus 292°F. Too cold for life.But cold enough for methane to liquefy. Titan is right on the edge of having large amounts—oceans, perhaps—of liquid methane.
“Titan may be the only other place in the solar system that has liquid on its surface,” says Toby Owen. He believes there are at least lakes of methane.
Methane in Titan’s nitrogen atmosphere might well rain or snow out. So will fine par¬ticles of other hydrocarbons—what we call smog. “If the surface is solid, there could be four and a half billion years’ worth of smog snow, maybe a kilometer deep, covering the moon,” says Jim Pollack.
“A few degrees could make a very big dif¬ference on Titan,” suggests Eshleman. The surface might differ from pole to equator. One region could melt in summer and then freeze 15 Earth years later, when the Titan winter arrives.
If there are lakes or oceans, the falling smog snow would make them sludgy. “There should be some very interesting chemistry going on,” says Owen.
JANUARY 6, 1981. Over catfish and crab fingers in a Baton Rouge restau¬rant, Voyager’s geologists are trying to decide what to say in their preliminary sci¬ence report. This impromptu dinner is a break from a NASA planetary-geology meeting. The subject is moons.
Rich Terrile, one of the younger team members, is being grilled across the table about his ideas on Enceladus. There has been speculation that Enceladus could be caught in a tidal tug-of-war between Saturn and Dione. This tugging could be heating Enceladus’s interior. The moon could be Trading insights while the first data on Saturnian wind speeds and directions are plotted, Andrew Ingersoll and Reta Beebe begin the long, detailed process of putting numbers to observed phenomena. As mis¬sion chief scientist Edward C. Stone has put it, “Until you have numbers, you don’t have a science.”