The weapon had been engineered to maximize its production of neutrons, which would be absorbed by the top few inches of the crust. The irradiated shell would heat, expand and spill away, thus imparting a rocket-like stress wave impulse to the asteroid.
From now on, until the mission reached its conclusion, Jiang Ling was a passenger.
She found the thought oddly restful.
She went to her sleeping cupboard, and retrieved the small brass bell. She rattled it, and the small clapper rang against the wall of the bell, and she stared into the corpulent, smiling face of ta laorenjia.
She ate a final breakfast. She found the ground crew had packed a special, final meal: duck, pork with rice, and even a small bulb of ckemshu, a rice liqueur.
She ate with relish. Then she carefully tidied away the plate and cutlery and enclosed microgravity cups.
It was hard to imagine that in a few minutes none of this familiar cabin and environment would exist; it was right to behave as if that were not so.
According to her mission clock, the final moment was mere seconds away. She had requested that the cabin camera be disabled, and that the radio link be kept silent.
She didn’t want a countdown. And she had said her good-byes.
The last person she had embraced, on Earth, was her mother.
A little before detonation, Jiang Ling pressed her fists into the sockets of her eyes.
She saw the complete bone structure of her hands, like an X-ray, drenched in pink light.
There was a moment of heat—
It was Benacerraf who found the methane vent.
As, despite her mountain-top adventure, she continued to ban any EVA beyond the walk-back limit, Rosenberg had set up a systematic program to take atmospheric and surface samples from the area around Tartarus they could reach in a couple of hours. So he sent Benacerraf in her snowshoes striking across the featureless, dull ground to the north-west. After a couple of miles, as he had instructed, she filled up her little sample bottles and started to return.
As she returned — taking a sighting on the white crest of Mount Othrys, visible as a hulking silhouette through the haze — she came upon a place where the gumbo appeared to have a different consistency, a lighter color.
She stopped, right in the middle of the discoloration patch.
She dug at the gumbo with her snowshoe, and bent down to take a closer look. The light was even worse than usual; they were coming to the end of one of the eight-day-long Titan “days,” and the methane overcast was heavy. But even in the dim, dried-blood light, she could see there was something unusual about the gumbo here. It was peppered by big, flattened bubbles. And as she watched, a fresh bubble emerged from under the tholin, spreading and flattening, streaks of color swimming in its surface.
She must have walked right over this patch on the way out. Whatever this was, it was out of the ordinary, surely the kind of thing Rosenberg had them out here looking for.
She bent, awkwardly, and took fresh sample bottles from her EMU pockets. She took a scraping of the gumbo itself, the air above the gumbo, and — with reasonable skill, she thought — managed to insert the plastic needle of a syringe into a bubble without breaking the sticky meniscus, and was able to draw out the uncontaminated gases within.
She straightened up, labelled the bottles, noted her location and walked on.
Back at Tartarus, inside the scuffed, patched-up, shack-like interior of the hab module, Rosenberg was distracted. He was busy trying to rebuild a balky nutrient pump from the CELSS farm, and he told her to store her sample bottles and he’d check them when he had time.
Meanwhile, Angel was having one of his bad days. He raged around the hab module, frustrated at his inability to perform the simplest task unaided. He railed at the equipment, at the assholes at NASA who wouldn’t speak to them any more, at his crewmates.
For all the difficulties his presence posed on even the simplest EVA, it was outside the cramped, battered, stale confines of the hab module that Angel seemed most stable. The opportunity to get him outside hadn’t come up for a couple of days, though, and now they were likely to be shut in through the eight-day Titan night. And already, Benacerraf thought, they were paying the price.
She made a meal for Angel, and sat him down in the Apollo couches. He rambled about his life, his space missions, his career, his father, even his sexual experiences. She sat and endured.
Listening to him was an easy safety valve.
Rosenberg padded around them in house shoes improvised from Beta-cloth scraps, and got on with his work on the pump. He didn’t actually do anything to help her with Angel; it was clear that as far as Rosenberg was concerned, Angel was Benacerraf’s problem, a waste of resources who ought to be pushed out the airlock.
It took Rosenberg two hours to get around to those anomalous samples.
Then he came bustling in from the Spacelab, shouting about an immediate EVA.
Benacerraf glanced uneasily at Angel. But he seemed to be heading into one of his inward-looking, passive phases. He was rocking to and fro in his couch, his right leg tapping rapidly, his head turning to and fro. She had learned to read Angel’s moods; if he stayed in this state, he was so shut-in it was beyond the power even of Rosenberg’s noisy, unstructured ranting to irritate him.
Rosenberg was still talking about going out.
“Slow down, Rosenberg,” she said. “You know we’ve avoided EVAs at night.”
“I know,” he said. “I know. But this is exceptional. We have an opportunity, right now, and we don’t know when it will recur. We’ll miss out on it if we wait seven or eight days for the fucking sun to come up.”
“What opportunity?”
“Paula, I analysed those samples you brought back. The anomalous tholin, the bubbling—”
“I remember.”
“You know what I found, in the sample you took from within the bubble?” He grinned. “Guess.”
“Don’t play games, Rosenberg.”
“Methane,” he said. “Almost pure methane gas. You see?”
She thought it over. “No. No, I don’t get it. The air is full of methane. We even produce it ourselves. Why should we care enough about methane to risk our necks out there in the dark?”
“Because of where the methane comes from,” he said rapidly. “It has to be from an underground reservoir. There are probably pockets of methane scattered all through the bedrock ice, though not all so close to the surface… It has to be an intrusion of the magma, the deep ammonia-water, which is forcing that methane to the surface now. And if that’s so, the site you found is one of the best possibilities for finding traces of ammono-analogue biology. Short of dropping into the caldera on Othrys, we—”
“Woah.” She held up her hands again. “Tell me slowly.”
“I’m talking about life,Paula,” he said softly. “Titan life: life beyond Earth. That methane vent represents one of our best chances of detecting it. If we sit in here on our butts, we may miss it.” He was struggling to be patient, she saw. “Do you get it? I’m not interested in the methane for itself. I’m interested in the ammonia-water magma.”
“Because—”
“Because if we’re going to find life anywhere, ammonia-analogue life, it’s in the fluid of the ancient oceans. Where liquid ammonia is still available, as a solvent. And that’s bubbling up out of the ground, a couple of miles away.”
Angel turned his ruined face to Rosenberg. “Titan life, huh. So, what use is that? Can we eat the shit?” He shook his head, mumbling irritably, and retreated inward to his crooning.
“Actually,” Benacerraf said drily, “he has a point, Rosenberg. This is science, not survival. I don’t think we should put ourselves in a life-threatening situation for—”