Stephen Baxter - Moonseed

“What?” Jays looked at him vaguely, a little dazzled by Moonlight; he’d heard maybe one word in three. “What are you talking about?”

And so, he missed the moment of detonation.

…And Henry thought he felt the shock of the detonation: the gentlest of tremors transmitted through the layers of his suit, waves in the rock, passing through the silent heart of the Moon, from an explosion the planet’s width away.

He should get back to the shelter in the lava tube. He turned and loped over the regolith, rock flour deposited by billions of years of meteorites, lunar ground never broken by a human footstep before.

The shock wave from the bunker-buster punched down into the strata of ice and dust, crushing the ancient layers, and slammed into the bedrock crust beneath. A central ball was flashed to vapour, which strove to flee the explosion. Surrounding layers of dirty ice were smashed and crushed, and the cavity expanded, growing at last to a hundred yards across.

When the stellar energy of the initial explosion faded, the weight of the layers above bore down on the cavity. It caved in, and layers of rubble collapsed down into it and over each other, forming a deep rubble chimney four hundred yards tall. It was surrounded by a fracture zone, cracks racing outwards, and its base was lined with radioactive glass, the remnants of the rock dust layers.

When the chimney collapse reached the surface, volatiles — water and carbon dioxide steam — began to fount from the growing crater. It was a volcano, of water and air…

Jane had found too many symptoms to ignore, now. Changes in her bowel habits. Blood in her stools and urine; pain when she pissed. Sores in her mouth that wouldn’t heal; hoarseness and coughs and difficulty swallowing; bleeding between her normal periods. It was as if she had wished this illness on herself, and now it was coming true.

She knew she would have to face it, go find a doctor. But that would confirm what she feared. It would be like picking up the revolver to play Russian Roulette —

“I can see it,” Jack said. “I can see it. Wow.”

Jane lifted the toy telescope. The Moon leapt into detail, the craters at the terminator finely detailed by shadow, her view obscured only by the trembling of her hands and by the false-colour spectral rings of the cheap lens.

She’d almost missed the flash, the few seconds after ignition: the moment when fire touched the surface of the Moon, shining over the southern limb, brought there by human hands. Already that glow was fading. But she could see the consequences.

There was a cloud, of yellow-white vapour, which fountained up — it must have been tens of miles high to be visible from here — erupting from the limb of the Moon into the darkness of space, in slow snakes, fingers of gas.

Henry was right: there was ice at the Pole, and here was the proof of it.

The soft white glow fell back, already much brighter than the Moon’s native glow, splashing against the Moon’s grey surface, and racing over that barren ground.

For a moment she felt a stab of regret. What harm had the Moon ever done humanity? For billions of years it had patiently regulated the tides, drawing up the sap in oceans and plants and humans. It was inspiration for a million myths, maybe more bad love songs, and dreams of flight.

And now, just a few decades after humans first reached it, we’ve visibly wounded it, she thought. Whatever the outcome of all this in human terms, it must be a tragedy for the Moon.

But some of the vapour was dissipating, great wisps of it branching away from the Moon. Perhaps it was escaping from the Moon’s gravity well altogether.

Maybe the new atmosphere wouldn’t stick.

She watched anxiously as the flower of steam blossomed on the surface of the Moon.

Now Sixt was using the Air Force glasses. “Oh, my God,” he kept saying. “Oh, my God.” Over and over.

Jays sat down in a rickety old chair that had once, it seemed, belonged to Edwin P. Hubble, who had used this telescope to observe distant galaxies, and so figure out that the universe is expanding. Jays craned his head back, and pressed his eye to the cylindrical eyepiece.

It took him a few moments to figure out how to see. He had to keep one eye closed, of course, and even then he had to align his head correctly, or his view would be occluded by the rim of the eyepiece.

A gibbous disc floated into his view. It was a washed-out grey with a splash of white at one part of the edge.

It was, of course, the Moon.

And he could see the vapour fountaining from its invisible source on the Moon’s far side. Some of it was escaping the Moon’s gravity. But most of it was falling back to the surface, and creeping sluggishly over the face of the Moon.

Right now, the vapour formed a loose cap, sitting over the South Pole region. It was growing, but with almost imperceptible slowness. It was like watching a mould spread across a smear of nutrient in a petri dish.

But it wasn’t growing uniformly. It seemed to be pooling, in the deeper craters and valleys incised into the Moon, before flooding on. In fact, it seemed to be flowing generally north-east — into the mouth of the Man in the Moon — avoiding the brighter area in the south-west corner of the visible face.

He knew the reason for that. The brighter area was the lunar highlands, older and higher than the grey areas, the lava-flooded maria. The volatiles Meacher had liberated were pouring over the Moon’s surface like fog, seeking out the low points, the crater pits and the valleys, the lava seas that flooded the great basins.

In a deep mare to the south — that must be Mare Nubium, he thought — he could almost see the surge of the air as it flowed, a bowl of atmosphere sloshing against eroded rim mountains like dishwater; and at the leading edges of the flood there were waves, hundred-mile crests distinctly visible, reflecting back from the basin’s walls like ripples in a bathtub, moving with a slug-like slowness.

It was, he thought, the first stirring of a new geography.

The cap of steam was much brighter, area for area, than the native surface of the Moon, which was starting to look drab by comparison. Earth’s reflective clouds of water vapour made it one of the brightest objects in the Solar System. And already, with maybe twenty per cent of the Moon’s surface covered, the Moon was much brighter than before…

He looked away from the eyepiece. He was slightly dazzled. When he looked down, the shadow of his liver-spotted hands against his shirt was much sharper than before.

Sixt was staring up at the Moon, its new light shining on his bare scalp. “My God,” he said. “You guys going up there, hopping around for three days, that was something. But now we’re changing the face of the Solar System. My God.”

Jays found he was trembling. Lights in the sky. He wanted to cower, hide like a dog under Edwin Hubble’s chair.

Henry — restless, excited — walked until he came to a rise, which he climbed in a few loping paces, and looked south.

The undulating lunar surface stretched away before him, its surface shaped by fractal crater layers into a frozen rocky sea. The sun was to his left — the east, for even after all that had happened it was still morning on the Moon — and he could feel the touch of its heat, through the thick layers of his suit. And the Earth was before him, a blue crescent: it was an old Earth, its phase locked in opposition to the new Moon’s. He imagined human faces all over that night side, turned up towards him, watching the Moon.

The sky above was still black, unmarked by the great events which ought to be occurring on the other side of the planet.

Ought to be.