Nemesis (22 page)

Judy waved and more or less staggered towards the dormitory. Webb felt his way along the pitch black corridor and stepped outside. The snowy landscape glowed softly in the light of the Milky Way and the stars. He breathed in the scented air, letting his eyes, strained by hours of terminal-staring, adapt to the dark.

The IAU circulars had revealed nothing.

Mars was high in the south, a bright red, unwinking beacon which, in a couple of hundred years, would hold a teeming human population, a population which would marvel at the havoc their ancestors had wreaked on the beautiful blue planet. A few lights were scattered over the desert far below.

He strolled on to the road which, that morning, he had pounded down with Leclerc and Whaler. Some animal screamed in the distance, a prolonged scream which set Webb’s nerves jangling.

The next step would be the SPITZER catalogue and maybe some ultraviolet stuff, maybe even going as far back as the IUE which had closed down in 1997. But he knew it wouldn’t wash; these were shots so long they had to be a last resort.

Something.

Something; a new idea trying to climb out from his subconscious. But what?

The animal screamed again, closer; or was it another animal? And what makes an animal scream in the night?

Suddenly cold and nervous, Webb turned back towards the observatory. He was asleep within two minutes of collapsing into bed.

Webb was in the cloister of a monastery, hiding behind a potted palm. In the cobbled central courtyard, hooded monks were building a scaffold. The carpenter, a monk with Noordhof’s face, had a row of six-inch nails protruding from his grinning mouth. They were hammering the scaffold together at superhuman speed, only the scaffold turned out to be a big wooden cross and the hammering was overwhelming and it transformed into an urgent tapping at Webb’s door, dragging him from his lurid subconscious world into the real one. The dream faded and Webb thought that perhaps Judy had overdone the chillies.

“Oliver!”

Feeling drugged, the astronomer heaved himself out of bed, put on a robe and opened the door, blinking in the subdued light of the hallway. Judy; still in her dressing gown, still with tousled blonde hair and tired, strained eyes. “Kenneth called. They think they’ve found something. He’s gone up in the cable car with Herb.”

Webb followed Judy down to the darkened conference room. Noordhof and Shafer were clustered round a terminal, the light from the screen giving a blue tinge to their faces. Shafer was in boxer shorts and singlet, and his hair was drawn back into a ponytail by an elastic band. Noordhof was fully dressed. The colonel moved aside and Webb looked at a hundred thousand stars. A wisp of nebulosity crossed the bottom of the screen, probably a remnant from some past stellar cataclysm. The starfield wasn’t drifting: someone had set the telescope for a long exposure.

“You see the little triangle of stars near the middle? The top one has moved.” Judy said.

“What’s its angular rate?” Webb asked.

“Extremely low,” Shafer said. “About a pixel an hour.”

“So it’s either heading away from us or straight at us.”

“It’s coming at us,” Shafer informed Webb. “It’s slowly brightening.”

“Have you any orbit at all?”

The physicist pointed to an adjacent terminal. The centre of the screen showed a coin-sized disc. A series of near-parallel lines criss-crossed the screen, the longer ones going from edge to edge; each line passed through the centre of the disc. “This is one of Herb’s programmes. We’re projecting the two-sigma error ellipses on to the target plane.”

“Only you don’t have distance information so the ellipses come out like lines.”

“That’s the problem. You see they’ve been shrinking as the data accumulate, but they still pass through the Earth. Collision is a definite possibility.”

“I agree, Willy, but so is a miss. These are still long lines. We need an accurate orbit and we’re not going to get that with a one-hour time base.”

“You said it yourself, Ollie. The Earth’s gravity pulls things in when they get close. In the last stages these lines will shrink to a point.”

“What are the chances, Ollie? Is this Nemesis?” Noordhof asked anxiously.

“At a minimum, it’s going to be a very close encounter.”

“What does that mean? Do I wake the President or not?”

Another elongated ellipse suddenly appeared on the screen, shorter than its predecessors. Its centre still passed firmly through the coin-sized Earth.

“This is it, right?”

Webb lowered his head in thought. “Mark, we’re not going to answer your question with the orbital dynamics to hand.”

“But we can’t wait. Not if this is the big one.”

Webb asked, “Do we have brightness information?”

Shafer nodded. “Herb says its magnitude has gone from twenty-one point five to twenty-one point two in the last hour.”

“I thought we weren’t looking fainter than seventeen?”

Shafer shrugged. “Mark ordered it. He’s still fixated with Baby Bears.”

Noordhof said, “Screw you, Willy. I made the right call and there’s the living proof.”

“Kenneth and Herb are trying to get its spectrum with the ninety-four-inch,” Judy volunteered.

Webb said, “At
m
equals 21? Full marks for effort. Look, the orbital accuracy is horrendous but we might be able to use
δm
. Anyone got a calculator?” Shafer thrust one into Webb’s hand. “Point three magnitude change translates into a roughly thirty per cent brightening in the last hour.”

“Maybe it’s just a rotating brick,” Shafer suggested.

“Too much light change in too short a time. Chances are the bulk of it is due to its approach. With inverse square its distance from us has decreased by fifteen per cent in the last hour. A spectrum is pointless. It’ll be on us in seven or eight hours.”

Shafer said: “Jesus.” The tone sounded more like a sudden conversion to Christianity than an oath.

Noordhof had an unlit cigar between his fingers. “If this is Nemesis we’re dead. Is it Nemesis?”

“Willy’s point about rotation is partly right. We just don’t know the approach rate precisely enough to be sure.”

“Wonderful!” Noordhof snarled. He crushed the cigar and threw it to the floor.

“Let’s guess it’s approaching at twenty kilometres a second. In six hours that puts it”—Webb tapped buttons on the calculator—“Crikey. Less than half a million kilometres away. What’s the time?”

Noordhof looked at the big railway clock. “Four fifteen.”

“From the way you guys have been operating I guess Kenneth’s supernova telescope has picked this thing up near the meridian. We’re probably looking at an eighty per cent sunlit face rather than a night-time crescent.”

“Make this quick, Webb,” said Noordhof. “The White House are going to need every second we can give them.”

Webb crossed to the blackboard and used his sleeve to wipe a clear space. There was just enough light to scribble. “A one-kilometre carbonaceous asteroid has magnitude 18 at one AU. This thing is 0.003 AU away which with inverse square luminosity would make it a hundred thousand times brighter than that, size for size. Use the magnitude/brightness formula

m
₂
= m
₁
+ 2.5 log (L
₁
/L
₂
)

Put
m
₂
18 and
L
₁
/
L
₂
100,000. At that distance, a one-kilometre asteroid would have magnitude 5.5. You could see it with the naked eye.” Webb stabbed the air with a piece of chalk. “But this one is 20.5, fifteen magnitudes fainter. For every five mags you go down, you lose a factor of a hundred in brightness. Ten mags down gives it only one ten thousandth of the intrinsic luminosity of a one-kilometre asteroid, ditto the surface area. This beast is less than a hundredth of a kilometre in diameter. Hey, we can relax. It’s only ten metres across.”

Shafer laughed. “A glorified beachball!”

“Are you sure?” Noordhof wanted to know.

Webb nodded. “At the ninety-nine per cent level. Even if it hits it’ll just be a brilliant fireball in the sky. We get these all the time. Colonel, you’re a fool. You’ve thrown away priceless hours of observing time. Forget the Baby Bears.”

An expression close to terror crossed Noordhof’s face. “I was about to waken the President.” A collective outburst of laughter relieved the tension. Judy headed for the kitchen and started to fill the coffee percolator.

“By the way,” Webb asked, “Where’s André?”

“He’s not in his room,” Judy called through.

“And he’s not up top,” Noordhof said.

Shafer put his hand to his mouth. “Ollie, I haven’t seen Leclerc since lunchtime.”

Webb looked at Noordhof. “Mark, it’s been a bad day. First a blind alley with your laser. Then a false alarm with this beachball. And now it seems that one of your team has gone missing.”

Judy pulled her dressing gown lapels round her neck and made for the dormitory. Webb, swaying with tiredness, headed in the same direction.

“Where do you think you’re going, Webb?”

“I’d have thought that was obvious, boss.” Webb saluted ironically.

“I’ve given thought to your friend’s automated telescope. The one in Tenerife. You say you can work it from here?”

“I can work it from here. The instructions go to Scott’s Oxford terminal and get routed through. Anyone sniffing cables at Tenerife would believe the operator was in Oxford.”

“With an external phone line? And an open modem?”

“Yes, for direct access. But it’s password protected and I have the password.”

“And your friend?”

“Scott’s in Patras. His wife is Greek and they’re with her family over Christmas. I have an open invitation to use the robotic telescope until it’s properly commissioned.”

“So, with half a million megatons coming in, and a telescope sitting idle, your action plan is to fall asleep.”

“I was waiting for your authorization, remember? Are you telling me you’re getting over your paranoia?”

“I have to balance risks here. Go ahead with it.”

“The sun’s up over Tenerife by now, Mark, but I’ll check that I can access it from here. Meantime, Herb and Kenneth must be turning into icemen, trying to get the
spectrum of your beachball. Why don’t you call them back down?”

Webb sat heavily down at the terminal Judy had been at. The chair was still warm. Another small ellipse had appeared on the screen, the disc representing the Earth still firmly inside it. By the time the bolide arrived the Pacific would be in darkness, and a brilliant shooting star would light up the night sky, to be seen only by the uncomprehending eyes of flying fish. He routed the picture over to an empty terminal, and typed in a file transfer protocol. Immediately, the terminal asked for his user-name and password. He gave these and a fresh window appeared on screen: he was now in effect sitting at his own computer in Wadham College. He asked for a second FTP to be opened up, the one linking him to the robotic telescope. Webb was asked for a PIN number. He supplied it and found himself in effect in Tenerife, at the console of Scott’s telescope, in little more time than it took to say Beam me up Scottie. The whole procedure had taken less than thirty seconds.

Webb could now use the mouse to control the movement of the telescope, little numbers at the top right hand of the screen giving the celestial co-ordinates at the centre of the starfield. The shutters of the telescope dome were closed in daylight hours, but he had confirmed that he could contact the telescope from here.

Then he switched to the external camera, mounted on a pillar about fifty yards from the main instrument.

The picture came through immediately. The camera was looking back at the telescope, whose silver dome was gleaming in the morning sunlight. He rotated the telescope dome and saw it swivel immediately. He scanned slowly, and the camera panned over the rocky foreground. A cluster of telescopes came into view, the massive William Herschel conspicuous amongst them. Someone was walking outside the big dome. He carried on scanning, and the camera picked up the tops of clouds further down the mountain; they were
above the inversion layer, and the atmosphere was likely very dry. He pressed another button and temperature, pressure, humidity and prevailing wind at the site were displayed. Then he swung the camera over the Tenerife sky; it was cloudless. Everything was operating smoothly. Tonight he would use the robot to search for Atens. As the signal came in to Eagle Peak it would automatically be reproduced a few hundred miles away, at Albuquerque, and the Teraflop would interrogate each picture element on the screen, comparing it with a digitized star chart and the co-ordinates of known asteroids. Any discrepancy would be recorded as a flashing point on the terminal VDU.

The thing would be to get as close as he could to the horizon, close to the sun but before the dawn light flooded the CCDs. Experimentally, he typed in an altitude and azimuth. Again the telescope’s response was swift.

In fact, remarkably swift: there was something odd.

Webb felt his scalp prickling.

His exhaustion suddenly lifted. He typed in another celestial co-ordinate. He tried a third and a fourth, each one with the same amazingly fast response.

He took a surreptitious look around. Shafer was at a terminal, leaning back in his chair, arms flopped at his side. With his eyes half shut and mouth half open, and with his stubble and ponytail, he looked more like a moron in a gangster movie than one of the sharpest scientists on the planet. Noordhof was at the conference table reading some report. Both men seemed past the point of exhaustion. Quietly, Webb logged on to the Internet and navigated his way to an infrared satellite image of Europe and North Africa. The image was less than ten minutes old. Tenerife and La Palma were covered with cloud. No mountain tops protruded above them. And yet the Tenerife camera was showing a clear, sunny sky.

Slowly, a fact almost beyond comprehension sank into Webb’s mind.

The observations from the robot telescope were a fake.