Lucifer's Hammer

“A cubic mile to play with. Five thousand two hundred and eighty feet, times twelve for inches, times two point five four for centimeters, cube that… We have two point seven seven six times ten to the fifteenth cubic centimeters of vanilla ice cream. It would take a while to eat it all. Times the density, and lo, we have about two times ten to the fifteenth grams. Couple of billion tons. Now for the fudge…” Sharps punched away.

Happy as a clam, Harvey thought. A very voluble clam equipped with Texas Instruments’ latest pocket marvel.

“What do you like for the density of hot fudge?” Sharps asked.

“Call it point nine,” Forrester said.

“Haven’t any of you made fudge?” Charlene demanded. “It doesn’t float. You test it by dripping it into a cup of cold water. Or at least my mother did.”

“Say one point two, then,” Forrester said.

“Another billion and a half tons of hot fudge,” Sharps said. Behind him Hamner made more strangled noises.

“I think we can ignore the rocks,” Sharps said. “Do you see why, now?”

“Lord God, yes,” Harvey said. He looked at the camera with a start. “Uh, yes, Dr. Sharps, it certainly makes sense to ignore the rocks.”

“You’re not going to show this, are you?” Tim Hamner sounded indignant.

“You’re saying no?” Harvey asked.

“No… no…” Hamner doubled over and giggled.

’Now, she’s coming at cometary speeds. Fast. Let’s see, parabolic speed at Earth orbit is what, Dan?”

“Twenty-nine point seven kilometers per second. Times square root of two.”

“Forty-two kilometers a second,” Sharps a

“Sounds good,” Forrester said. “Meteors go from twenty to maybe seventy. It’s reasonable.”

“Right. Call it fifty. Square that, times a half. Times mass in grams. Bit over two times ten to the twenty-eight ergs. That’s for the vanilla ice cream. Now we can figure that most of the hot fudge boiled away, but understand, Harvey, at those speeds we’re just not in the atmosphere very long. If we come in straight it’s two seconds flat! Anyway, whatever mass you burn up, a lot of the energy just gets transferred to the earth’s heat balance. That’s a spectacular explosion all by itself. We’ll figure twenty percent of the hot-fudge energy transfers to Earth, and” — more buttons pressed, and dramatic rise in voice — “our grand total is two point seven times ten to the twenty-eighth ergs. Okay, that’s your strike.”

“Doesn’t mean much to me,” Harvey said. “It sounds like a big number…”

“One followed by twenty-eight zeros,” Mark muttered.

“Six hundred and forty thousand megatons, near enough,” Dan Forrester said gently. “It is a big number.”

“Good God, pasteurized planet,” Mark said.

“Not quite.” Forrester had his own calculator out of the belt case. “About three thousand Krakatoas. Or three hundred Thera explosions, if they’re right about Thera.”

“Thera?” Harvey asked.

“Volcano in the Mediterranean,” Mark said. “Bronze Age. Where the Atlantis legend comes from.”

“Your friend’s right,” Sharps said. “I’m not sure about the energy, though. Look at it this way. All of mankind uses about ten to the twenty-ninth ergs in a year. That’s everything: electric power, coal, nuclear energy, burning buffalo chips, cars — you name it. So our hot fudge sundae pops in with about thirty percent of the world’s a

“Um. Not so bad, then,” Harvey said.

“Not so bad. Not so bad as what? A year’s energy in one minute,” Sharps said. “It probably hits water. If it hits land, it’s tough for anyone under it, but most of the energy radiates back out to space fairly quickly. But if it hits water, it vaporizes it. Let’s see, ergs to calories… damn. I don’t have that on my gadget.”

“I do,” Forrester said. “The strike would vaporize about sixty million cubic kilometers of water. Or fifty billion acrefeet, if you like that. Enough to cover the entire U.S.A. with two hundred and twelve feet of water.”

“All right,” Sharps said. “So sixty million cubic kilometers of water go into the atmosphere. Harvey, it’s going to rain. A lot of that water is moving across polar areas. It freezes, falls as snow. Glaciers form fast… slide south… yeah. Harvey, the historians believe the Thera explosion changed the world’s climate. We know that Tamboura, about as powerful as Krakatoa, caused what historians of the last century called ‘the year without a summer’. Famine. Crop failure. Our hot fudge sundae will probably trigger an ice age. All those clouds. Clouds reflect heat. Less sunlight gets to Earth. Snow reflects heat too. Still less sunlight. It gets colder. More snow falls. Glaciers move south because they don’t melt as fast. Positive feedback.”

It had all turned dead serious. Harvey asked, “But what stops ice ages?”

Forrester and Sharps shrugged in unison.

“So,” Hamner said, “my comet’s going to bring about an ice age?” Now you could see the long lugubrious face of his grandfather, who could look bereaved at a $60,000 funeral.

Forrester said, “No, that was hot fudge sundae we were talking about. Um — the Hammer is bigger.”

“Hamner-Brown. How much bigger?”

Forrester made an uncertain gesture. “Ten times?”

“Yes,” said Harvey. There were pictures in his mind. Glaciers marched south across fields and forests, across vegetation already killed by snow. Down across North America into California, across Europe to the Alps and Pyrenees. Winter after winter, each colder, each colder than the Great Freeze of ’76–’77. And hell, they hadn’t even mentioned the tidal waves. “But a comet won’t be as dense as a cubic mile of h-h-h—”

It was just one of those things. Harvey leaned back in his chair and belly-laughed, because there was just no way he could say it.

Later he made his own tape, alone, in a studio approximation of an office — fake books on the shelves, worn carpet on the floor. Here he could talk.

“Sorry about that.” (This would run just after one of Harvey’s breakups. He’d done that several times in the Sharps interview.) “The points to remember are these. First, the odds against any solid part of Hamner-Brown hitting us are literally astronomical. Over these distances even the Devil himself couldn’t hit a target as small as Earth. Second, if it did hit, it would probably be as several large masses. Some of those would hit ocean. Others would hit land, where the damage would be local. But if Hamner-Brown did strike the Earth, it would he as if the Devil had struck with an enormous hammer, repeatedly.”

April: Interludes

Fifty thousand years ago in Arizona:

Friction with the air makes the surface incandescent as the oxygen in the atmosphere blowtorches the iron. From this great flying mass, sputtering chunks as large as houses fly of’ as the meteoroid, travelling at a low angle, nears the ground. A huge cylinder of superheated air is forced along by the meteoroid and, as it strikes, this air is forced across the surrounding countryside in a fiery blast that instantaneously scorches every living thing for a hundred miles in every direction.

Leonilla Malik scribbled a prescription and handed it to her patient. He was the last for the morning, and when the man had left her examining room, Leonilla took the bottle of Grand Marnier from her lower desk drawer and poured a small, precious glass. The expensive liqueur was a present from one of her fellow kosmonauts, and drinking it gave her a delicious feeling of decadence. Her friend also brought her silk hose and a slip from Paris.

And I’ve never been outside Russia, she thought. She let the sweet fluid roll over her tongue. No matter how I try, they will never let me go.