Zoe wasn’t convinced. “But look at it. A perfect geometric figure with six sides of exactly equal length, unchanged for decades? You’re telling me that just happened by accident?”
“The universe is a big place,” Shaun reminded her. “There’s time and space enough for all sorts of unlikely occurrences. Anything that can happen probably has.”
“Like mysterious alien science projects?” Zoe said. “Who knows? Maybe there’s some weird black monolith at the center of the hexagon.”
“Not on this space odyssey,” Shaun said. “I don’t know about you, but I’m not planning to evolve into a higher form of life anytime soon.”
Zoe winked at him. “Speak for yourself.”
“Jesus,” Fontana said, exasperated. “You really don’t know when to give up, do you?”
“Would I be here if I did?”
“My point exactly.”
Shaun intervened before Saturn witnessed its first zero-gravity catfight. “In any event, I hope we’ll learn a lot more about that storm, and the rest of Saturn’s weather patterns, while we’re in the neighborhood.”
The plan was to settle into a polar orbit threading the planet’s rings and study Saturn and its moons for fourteen days before turning around and heading home. NASA expected them to accumulate enough data to keep scientists back on Earth occupied for years. With any luck, some of the data might actually explain the enigmatic hexagon once and for all.
“Indeed,” O’Herlihy said. “I’m looking forward to checking out the magnetometer readings on that storm, not to mention getting a close-up look at that comet.”
The comet was only a misty smudge in the distance at this point. In theory, it would be joining them any day now.
“This is where your work really starts,” Shaun said. O’Herlihy was the chief scientist on this mission; he would be taking center stage now. “I’m just glad we got you here in one piece.”
“I appreciate the smooth ride, Colonel,” O’Herlihy said. “My thanks to you and your esteemed copilot.”
“You’re welcome,” Shaun said. “Recommend us to your friends.”
“Hey, I’ve got an idea.” Zoe waved her hand in the air to get their attention. “How about I take a snapshot of the three of you at this historic moment? Years from now, you can even pretend I wasn’t here.”
“Oh, I’m already doing that,” Fontana said. “Trust me.”
“Not a bad idea, though,” Shaun said. NASA had issued them a couple of digital cameras so they could capture candid moments of life aboard the ship. The public-relations folks intended to get plenty of mileage out of the photos later; there was even talk of a coffee-table book and a calendar. “Let’s do it.”
He retrieved a camera from a supply locker and flew it over to Zoe. There was no need to lob it to her in an arc; momentum carried it across the cabin in a straight line. She snatched it out of the air and backed up to get the three astronauts in her sights.
“Okay, then,” she said. “All together now, in front of the big pretty planet.”
The crew posed in front of the cockpit windows, their feet not touching the floor. They were literally walking on air. Fontana took the center spot, flanked by the two men.
“Squeeze together closer,” Zoe urged them. “C’mon, Skipper, put your arm around Fontana. Don’t be shy.”
Zoe gave Shaun a puckish smirk. He resisted the urge to glare back at her. That probably wouldn’t look good in the photos.
Smiling, he hugged Fontana and felt her own arm slip around his waist. She gave his hand a furtive squeeze and beamed at the camera. O’Herlihy leaned in from the other side of her.
“Perfect!” Zoe decreed. “Everybody say ‘hexagon.’”
“Hexagon!” they shouted in unison. A flash lit up the flight deck.
As Shaun recalled, they still had one bottle of champagne left.
“LIDAR still tracking the comet,” O’Herlihy reported. “It’s right on schedule.”
Today was Comet Day. The Lewis & Clark had been in a polar orbit around Saturn, perpendicular to the rings, for more than seventy-two hours. That was more than a week by Saturn time, since the planet rotated completely every ten hours or so, giving them numerous chances to observe both its eastern and western hemispheres. They were orbiting the planet at a distance of twenty thousand kilometers, which conveniently allowed them to pass through the Cassini Division without colliding with the rings. The ship’s hull was tough enough to withstand a few minor impacts, but nobody felt like tempting fate by plowing through the rings themselves.
Today, Saturn was just a backdrop, however. Their agenda was to observe the comet close-up and guide an unmanned probe to take samples of both its icy crust and its inner core. The probe, which had been christened Sacagawea, was already waiting outside the ship to intercept the comet. The goal was to land it on the comet’s surface so that it could transmit its findings back to the Lewis & Clark. Christopher and Fontana had spent most of yesterday launching it from the ship’s cargo bay.
Zoe drifted about the flight deck, staying more or less out of the way. “The comet’s not going to hit the rings, is it?”
“Not a chance,” Shaun said from the helm. “It’s going to swing past Saturn at a distance of about two hundred twenty-five thousand kilometers, well clear of the rings.”
“Too bad. That would have been quite a show.” Zoe floated over to one of the auxiliary consoles, where O’Herlihy was directing Sacagawea by remote control. She tapped the scientist on the shoulder. “So, I’ve been meaning to ask you. Now that we’re here, what’s the story with the rings, anyway? Are they more or less wobbly than you expected?”
He looked up from his terminal with a slightly sheepish expression. “To be honest, my preliminary observations indicate that the rings do seem to be rather more… unstable than originally anticipated.”
This was news to Shaun. He had been focused for the last few days on getting the probe launched in time to intercept the comet. He had left the pure scientific research to O’Herlihy, on the assumption that it was way too early to draw any definitive conclusions from the data they had just started accumulating. Chances were, scientists would be chewing over the data for years to come.
“How unstable, Doc?” he asked.
“Hard to say,” O’Herlihy answered. “You have to remember, the rings have always been a dynamic system, full of troughs and waves and clumps. Some of the ringlets are even braided together, particularly out by the F Ring. The whole system is constantly in motion. Indeed, there’s reason to believe that the rings are a relatively new and temporary phenomenon, that they did not even exist a few hundred million years ago, when the early dinosaurs were first roaming the Earth, and that they may be gone for good millions of years from now.”
“And yet?” Shaun prompted him.
“Well, I’m hesitant to jump to any rash conclusions without further evidence…”
Shaun grew impatient. “Enough with the obligatory disclaimers, Doc. I don’t want to wait for the peer-reviewed version. Cut to the chase.”
“All right,” the scientist said reluctantly, “but bear in mind that this is just off the cuff. I still need to collect more evidence and conduct a more detailed analysis.”
“Understood. But…?”
“The rings appear to be collapsing inward — at a steadily increasing rate. Debris from the outer rings is spiraling into the inner ones, whose orbits are gradually shrinking as well. The divisions between the rings are also narrowing, causing discrete rings to blur together much more than usual.”
Shaun wondered what this meant for their mission. “Is there any danger to the ship?”
“I shouldn’t think so. The ring matter is falling inward, toward the planet, not aiming at us, although I’m at a loss regarding what might be causing this or why it is happening now. Frankly, it’s quite unexpected… and more than a little baffling.”