By midafternoon the weather balloon was swelling nicely.

“How much hydrogen do you think we’ve got there?” Bernstein wondered.

“Not enough,” said Faiyum, serious for once. “We’ll need three, four balloons full. Maybe more.”

O’Connor looked westward, out across the bleak frozen plain. The sun would be setting in another couple of hours.

When they finished their day’s work and clambered back into the cockpit, O’Connor saw that the batteries were barely up to half their standard power level, even with the solar panels recharging them all day.

We’re not going to make it, he thought. But he said nothing. He could see that the other two stared at the battery readout. No one said a word, though.

The night was worse than ever. O’Connor couldn’t sleep. The cold hurt. He had turned off his suit radio, so he couldn’t tell if the other two had drifted off to sleep. He couldn’t. He knew that when a man froze to death, he fell asleep first. Not a bad way to die, he said to himself. As if there’s a good way.

He was surprised when the first rays of sunlight woke him. I fell asleep anyway. I didn’t die. Not yet.

Faiyum wasn’t in the cockpit, he saw. Looking blearily through the windshield he spotted the geologist in the early morning sun fixing a fresh balloon to the bore hole, with a big round yellow balloon bobbing from a rock he’d tied it to.

O’Connor saw Faiyum waving to him and gesturing to his left wrist, then remembered that he had turned his suit radio off. He clicked the control stud on his wrist.

“. . . damned near ready to burst,” Faiyum was saying. “Good thing I came out here in time.”

Bernstein was lying back in his cranked-down seat, either asleep or . . . O’Connor nudged his shoulder. No reaction. He shook the man harder.

“Wha . . . what’s going on?”

O’Connor let out a breath that he hadn’t realized he’d been holding.

“You okay?” he asked softly.

“I gotta take a crap.”

O’Connor giggled. He’s all right. We made it through the night. But then he turned to the control panel and saw that the batteries were down to zero.

Faiyum and Bernstein spent the day building a system of pipes that led from the balloon’s neck to the input valve of the repaired fuel cell’s hydrogen tank. As long as the sun was shining they had plenty of electricity to power the laser. Faiyum fastened the balloon’s neck to one of the hopper’s spidery little landing legs and connected it to the rickety-looking pipework. Damned contraption’s going to leak like a sieve, O’Conner thought. Hydrogen’s sneaky stuff.

As he worked he kept up his patter of inane jokes. “A Catholic, a Muslim, and a Jew—”

“How come the Jew is always last on your list?” Bernstein asked, from his post at the fuel cell. O’Connor saw that the hydrogen tank was starting to fill.

Faiyum launched into an elaborate joke from the ancient days of the old Soviet Union, in which Jews were turned away from everything from butcher’s shops to clothing stores.

“They weren’t even allowed to stand in line,” he explained as he held the bobbing balloon by its neck. “So when the guys who’ve been waiting in line at the butcher’s shop since sunrise are told that there’s no meat today, one of them turns to another and says, ‘See, the Jews get the best of everything!’”

“I don’t get it,” Bernstein complained.

“They didn’t have to stand in line all day.”

“Because they were discriminated against.”

Faiyum shook his head. “I thought you people were supposed to have a great sense of humor.”

“When we hear something funny.”

O’Connor suppressed a giggle. Bernstein understood the joke perfectly well, he thought, but he wasn’t going to let Faiyum know it.

By the time the sun touched the horizon again, the fuel cell’s hydrogen tank was half full and the hopper’s batteries were totally dead.

O’Connor called Tithonium. “We’re going to run on the fuel cell tonight.”

For the first time since he’d known her, Gloria Hazeltine looked surprised. “But I thought your fuel cell was dead.”

“We’ve resurrected it,” O’Connor said happily. “We’ve got enough hydrogen to run the heaters most of the night.”

“Where’d you get the hydrogen?” Glory Hallelujah was wide-eyed with curiosity.

“Bug farts,” shouted Faiyum, from over O’Connor’s shoulder.

They made it through the night almost comfortably and spent the next day filling balloons with methane, then breaking down the gas into its components and filling the fuel cell’s tank with hydrogen.

By the time the relief ship from Tithonium landed beside their hopper, O’Connor was almost ready to wave them off and return to the base on their own power.

Instead, though, he spent the day helping his teammates and the two-man crew of the relief ship attach the storage racks with their previous ice core onto the bigger vehicle.

As they took off for Tithonium, five men jammed into the ship’s command deck, O’Connor felt almost sad to be leaving their little hopper alone on the frigid plain. Almost. We’ll be back, he told himself. And we’ll salvage the Viking 2 lander when we return.

Faiyum showed no remorse about leaving at all. “A Jew, a Catholic, and a Muslim walk into a bar.”

“Not another one,” Bernstein groused.

Undeterred, Faiyum plowed ahead. “The bartender takes one look at them and says, ‘What is this, a joke?’”

Even Bernstein laughed.

A PALE BLUE DOT

Galileo wrote, “Astronomers . . . seek to investigate the true constitution of the universe—the most important and most admirable problem that there is.”

Looking across the frontier of space, astronomers have found in recent years thousands of planets orbiting other stars. But so far, none of these exoplanets resembles Earth very closely. No one has yet found a “pale blue dot” like our own planet out among the stars.

Not yet.

But the search goes on, year by patient year, using constantly better instruments and ideas. Sky-scanning telescopes dot mountaintops all across our world. Telescopes have been placed in space, to look farther and better.