Impact

43

Ford stepped out of the dinghy onto the rocks of Shark Island and breathed deeply of the salt air. He was glad to be on solid ground--the boat ride off shore, even in a calm ocean, had left him queasy. He was not, it must be admitted, a sailor. The brilliant summer day bathed the island in warm sunlight and the ocean lay shimmering from mainland to sea horizon. Seagulls cried and wheeled about above their heads, irritated at being disturbed from their habitual resting places on the shore rocks.

"Don't soil your Guccis," Abbey said.

He followed her to the top of the island, picking his way among rocks and bayberry bushes, and in a moment found himself at the edge of a small crater. The recent rains had washed clean the fractured bedrock at the bottom of the crater. In the middle of the bedrock, surrounded by cracks, Ford could see a perfect hole, about three inches in diameter.

He took a deep breath. What could have made an entry hole of three inches, pass through eight thousand miles of planet, and exit, making a hole ten feet across?

"We went to find a meteorite," said Abbey, "and that's what we found: a hole." She laughed ruefully.

Ford slipped a handheld radiation meter out of his gear bag. It registered normal background radiation only, about 0.05 millirem per hour. He took some pictures and got a GPS fix on the hole. Then he crouched and took a reading inside the hole itself, passing the RadMeter back and forth. It finally registered a slight uptick, to 0.1 millirem/hr.

"Am I going to have two-headed children?"

"Hardly."

He slipped into the crater and knelt, reaching inside the hole with his fingers and feeling around. The walls were smooth and glassy, just like the walls of the bigger hole in Cambodia. The extraterrestrial object--whatever it was--had bored a round cylinder in the rock as perfect as if it had been drilled. Cracks radiated outward, but there was little sign of violence and almost none of the usual explosive contact that occurs on impact--the hole was amazingly clean, the ground hardly disturbed. It was as if some unusual force had absorbed or canceled out the energy of the impact. The same thing must have happened at the far side of the Earth, in Cambodia. The exit hole should have been enormous, like that made by a bullet passing through a pumpkin, the shock wave alone blowing debris out the far end and leaving an active volcano or eruption of magma. But no. Both holes had somehow sealed themselves up at both ends. No magma, no eruption, just residual radiation. It made no sense. Anything large and fast enough to vaporize a hole in rock and actually drill through the Earth would have blown the island to smithereens.

Ford peered down the hole with a flashlight; it went straight down as far as the beam could reach. He shivered. Something about this business frightened him; he wasn't sure why. He measured the hole, recorded the entry angle on it, took some pictures. Getting his rock hammer out of his pack, he chipped a few fragments from the lip of the hole, some displaying the glassy inner wall, and sealed them in ziplock bags. He also took samples of dirt and plants.

"How the heck," said Abbey, "could a meteor big enough to light up the Maine coast only leave a tiny hole like that?"

"A damn good question." Ford rose to his feet, brushed the dirt off his knees.

"How deep do you think it went before it finally stopped?"

Ford cleared his throat and looked at her. "It didn't stop."

"What do you mean?"

"It went all the way through the Earth."

She stared at him. "You're kidding me, right?"

"No joke. It came out in northwestern Cambodia. Only it was a lot bigger when it exited--the hole wasn't three inches in diameter, it was ten feet."

"Holy shit."

"It blew out of the ground with such force that it flattened a square mile of jungle."

"Any idea what it was?"

Ford began packing up his gear and samples. "Not a clue."

"Sounds like a miniature black hole to me. Goes all the way through the Earth, getting bigger as it goes, leaves behind traces of radiation."

"That's an intriguing hypothesis."

"Have you figured out where it came from?"

Ford hefted the bag. "No."

"Why not?"

Ford sighed. "And how would one do that?"

"You've got a photograph of it coming in, you've got the entry point and angle, exact time of impact, exit point and angle--heck, with that information I'm pretty sure you could extrapolate its orbital trajectory backward. They do it all the time with ECOs."

"ECOs?"

"Earth Crossing Objects. It's a classic problem of orbital dynamics."

Ford stared at her. "Could you do it?"

"Gimme an hour and a MacBook running Mathematica."