Green Mars(48)

He was still thinking things over, and typing at the keypad of the lock door like a champion speed-typist, when he was tapped hard on the shoulder. “Aaa!” he shouted, leaping around.

There were two of them, in walkers and scratched old helmets. Through their faceplates he could see them: a woman with a face like a hawk’s, who looked like she would be happy to bite him; and a short thin-faced black man, with gray dreadlocks crowding the border of his faceplate, like the rope picture frames one sometimes sees in nautical restaurants.

It was the man who had tapped Art on the shoulder. Now he lifted three fingers, pointing at his wrist console. The intercom band they were using, no doubt. Art switched it on. “Hey!” he cried, feeling more relieved than he ought to, considering that this was probably Nirgal’s setup, so that he had never been in danger. “Hey, I seem to be locked out of my car? Could you give me a lift?”

They stared at him.

The man’s laugh was scary. “Welcome to Mars,” he said.





Part Three



Long Runout





Ann Clayborne was driving down the Geneva Spur, stopping every few switchbacks to get out and take samples from the roadcuts. The Transmarineris Highway had been abandoned after ‘61, as it now disappeared under the dirty river of ice and boulders covering the floor of Coprates Chasma. The road was an archaeological relic, a dead end.But Ann was studying the Geneva Spur. The Spur was the final extension of a much longer lava dike, most of which was buried in the plateau to the south. The dike was one of several— the nearby Melas Dorsa, the Felis Dorsa farther east, the Solis Dorsa farther west— all of them perpendicular to the Marineris canyons, and all mysterious in their origin. But as the southern wall of Melas Chasma had receded, by collapse and wind erosion, the hard rock of one dike had been exposed, and this was the Geneva Spur, which had provided the Swiss with a perfect ramp to get their road down the canyon wall, and was now providing Ann with a nicely exposed dike base. It was possible that it and all its companion dikes had been formed by concentric fissuring resulting from the rise of Tharsis; but they could also be much older, remnants of a basin-and-range type spread in the earliest Noachian, when the planet was still expanding from its own internal heat. Dating the basalt at the foot of the dike would help answer the question one way or the other.

So she drove a little boulder car slowly down the frost-covered road. The car’s movement would be quite visible from space, but she didn’t care. She had driven all over the southern hemisphere in the previous year, taking no precautions except when approaching one of Coyote’s hidden refuges to resupply. Nothing had happened.

She reached the bottom of the Spur, only a short distance from the river of ice and rock that now choked the canyon floor. She got out of the car and tapped away with a geologist’s hammer at the bottom of the last roadcut. She kept her back to the immense glacier, and did not think of it. She was focused on the basalt. The dike rose before her into the sun, a perfect ramp to the clifftop, some three kilometers above her and fifty kilometers to the south. On both sides of the Spur the immense southern cliff of Melas Chasma curved back in huge embayments, then out again to lesser prominences— a slight point on the distant horizon to the left, and a massive headland some sixty kilometers to the right, which Ann called Cape Solis.

Long ago Ann had predicted that greatly accelerated erosion would follow any hydration of the atmosphere, and on both sides of the Spur the cliff gave indications that she had been right. The embayment between the Geneva Spur and Cape Solis had always been a deep one, but now several fresh landslides showed that it was getting deeper fast. Even the freshest scars, however, as well as all the rest of the fluting and stratification of the cliff, were dusted with frost. The great wall had the coloration of Zion or Bryce after a snowfall— stacked reds, streaked with white.

There was a very low black ridge on the canyon floor, a kilometer or two west of the Geneva Spur, paralleling it. Curious, Ann hiked out to it. On closer inspection the low ridge, no more than chest high, did indeed appear to be made of the same basalt as the Spur. She took out her hammer, and knocked off a sample.

A motion caught her eye and she jerked up to look. Cape Solis was missing its nose. A red cloud was billowing out from its foot.

Landslide! Instantly she started the timer on her wristpad, then knocked the binocular hood down over her faceplate, and fiddled with the focus until the distant headland stood clear in her field of vision. The new rock exposed by the break was blackish, and looked nearly vertical; a cooling fault in the dike, perhaps— if it too was a dike. It did look like basalt. And it looked as if the break had extended the entire height of the cliff, all four kilometers of it.