Moonseed

There was no evidence of a spherical shape. She made out a crudely-defined, blurred oval, with extensive tails, like a comet’s.

Alfred said, “You’re looking at a cloud of atmospheric gas, mostly frozen, and ground-up rock.”

“The rock’s from the surface?”

“Mostly the mantle, as far as we can tell. Most of the mass is still concentrated near the point where the centre of gravity of the planet used to be. We tried radar pulses from Arecibo, and… Well. Monica, we can’t find a solid object there any more. The substance of the planet is spreading out along the orbit. The ring probably won’t stay stable; the perturbation by Earth’s gravity will—”

“Hold it. Alfred, I can’t follow you. You’re saying that Venus no longer exists.”

“Not as a coherent solid, no.”

“That’s impossible. How much energy would it take to destroy a planet?

He considered. “Well, roughly speaking, you would have to lift every piece of rock to escape velocity, out of Venus’s own gravity well. There’s a quantity called the gravitational binding energy… For Venus, which had eighty per cent of Earth’s mass, it works out as ten to power thirty-two joules — umm, something like a thousand billion times our nuclear arsenal.”

“Just for the record, we aren’t talking about your global volcanic resurfacing here, are we?”

He smiled. “Even that would be quite a spectacle, if it occurred in the lifetime of this astronomer. But no, it’s orders of magnitude beyond that.” He rubbed his nose, smearing the gaudy sun block there. “Those are big numbers. But there’s another way of looking at it. If you consider the energy density required, averaged over the planet’s volume, it isn’t so high. Something like a tanker of gas per cubic yard or so, I guess.”

“What are you telling me?”

“We think we are looking at some fu

“Fu

“Look at this.” He pulled up results from a cosmic ray detector, tracks left in bubble chambers, accompanying analysis. “We’ve found some strange products from the Venus event. Some exotic beasties, escaping from that particular zoo. Have you seen this result?”

A spider-web of tracks, of splits and decay events and spirals and tiny explosions.

She whistled. “No. I’d remember.”

“Well, the results haven’t made it onto the nets yet. The authors are still checking.”

“I don’t blame them,” she said. “If this is right—”

“You’re looking at a particle with a charge a fraction of an electron’s. Which is something we’ve never seen before.”

“And this mass—” She looked at him. “Alfred, this is the signature of an elementary particle with a fractional charge, and the mass of a bacterium. Now, what processes do we know of which could produce such a thing?”

“We don’t know of anything since the Big Bang.” He studied her. “We’re measuring the symptoms here. Guessing at a cause isn’t so easy.”

“A cause?”

“A purpose, then. Something has taken Venus apart. It seems to have transformed the planet’s own mass-energy to use against it.” He gri

“Something? You make it sound as if this was somehow deliberate.”

He didn’t reply to that.

“Listen,” he said. “We’re on Hawaii. We should have ice cream. You want some ice cream?”

She shrugged, indifferent, and he went anyway.

After the Venus event Alfred had come here to the islands to work at the observatory on the summit of Mauna Kea, fourteen thousand feet above sea level. Up there, the air was so rarefied it was as clear a sky as anywhere on Earth, but human lungs only received forty per cent of their normal intake of oxygen. Nobody slept at the summit; the astronomers came down four thousand feet every dawn to sleep over at Hale Pohaku.

Alfred had come down to meet her. Monica knew there was no way she would be able to tolerate the summit conditions.

Thus, death was already closing in on her, already cutting the options available to her, the circles closing in. She would never see another mountain top.

Bullshit, she thought.

She tried to focus on Hawaii.

This island, Oahu, was dying too, though a little more slowly than she was. It had bloomed out of the sea in a fiery birth, amid gouts of lava and steam. But every year erosion dragged it down towards the water, and there was nothing, no process, to restore it.

It had happened before. There was a flaw in Earth’s mantle here, a great plume of magma which had welled up steadily for a hundred million years. It had generated Oahu; right now the Big Island was over the plume, and was being pushed towards the sky by that lithic fountain. But the relentless sliding of the tectonic plates beneath the Pacific would eventually, in a few million years, take the Big Island away from the plume. The volcano at its heart would die, and the island would be abandoned to the forces of erosion.

Thus there was a chain of dying islands tailing off to the northwest, Oahu and Kauai and Niihau, and beyond that a trail of corpses, nameless undersea mountains, each of which had once been a paradise of forests and beaches, just like this one.

Somehow it seemed an appropriate place to come to talk about the death of Venus.

Alfred returned, bearing two immense cones of ice cream. He was wearing a broad, floppy hat, a garish shirt, and shorts that made his legs look as if he had spent ten years in space.

They found a seat, and ate up the ice cream companionably.

Small talk: How are Garry and your grandkids? Fine, Alfred, when I get to see them… he’s flying out of Edwards now… I don’t think Jenine is enjoying life as an Air Force wife…

She let her attention drift. A part of her mind was already composing the report she would have to pass up to the Administration.

She wondered about telling the President about the fu

On the other hand, she thought bleakly, suppose Alfred’s wilder speculations have some bearing on reality. If there is something loose in the Solar System, something transforming, something powerful enough to destroy a planet like Venus — won’t it be seen immediately in terms of a threat to the Earth?

And if it was a threat, how could they possibly deal with it, even recognize it?

“You know,” Alfred was saying around his ice cream, “no matter what the other implications of this event, one thing’s for sure.”

“What?”

“We’ve lost Venus. Forever. Although I suppose the truth is we lost it a long time ago, when the first space probes got there. I’m old enough to remember—”

“You’re younger than me, Alfred.”

“ — when Arrhenius’s theory was still the paradigm. He thought the clouds were water droplets. The land was choked by swamps.

A hothouse, with amphibians and dinosaurs and cave men. Even later, when it became clear from the spectroscopic evidence there was no water in the cloud tops, we still thought there might be a loophole. Maybe a world-spa

“But when the Mariners got there, what they found was a big disappointment.” He shook his head. “But it needn’t have stayed that way. All those stupendous schemes to terraform Venus the fringe types cooked up. You’d have to block out the sun, and let all that carbon dioxide liquefy, strike it with comets to spin it up and bring in water—”

She laughed. “What bull.”