"You don't understand," he told Childrey. "Gravity radiation is harder to block than electromagnetic waves. Patterned gravity waves would be easy to detect. The advanced civilizations in the galaxy may all be communicating by gravity. Some of them may even be modulating pulsars—rotating neutron stars. That's where Project
Ozma went wrong: they were only looking for signals in the electromagnetic spectrum."
Childrey laughed. "Sure. Your little friends are using neutron stars to send you messages. What's that got to do with us?"
"Well, look!" Lear held up the strip of flimsy, nearly weightless paper he'd torn from the machine. "I got this over Sirbonis Palus. I think we ought to land there."
"We're landing in Mare Cimmerium, as you perfectly well know. The lander is already deployed and ready to board. Dr. Lear, we've spent four days mapping this area. It's flat. It's in a green-brown area. When spring comes next month, we'll find out whether there's life there! And everybody wants it that way except you!"
Lear was still holding the graph paper before him like a shield. "Please. Take one more circuit over Sirbonis Palus."
Childrey opted for the extra orbit. Maybe the sine waves convinced him. Maybe not. He would have liked inconveniencing the rest of us in Lear's name, to show him for a fool.
But the next pass showed a tiny circular feature in Sirbonis Palus. And Lear's mass indicator was making sine waves again.
The aliens had gone. During our first few months we always expected them back any minute. The machinery in the base was running smoothly and perfectly, as if the owners had only just stepped out.
The base was an inverted pie plate two stories high, and windowless. The air inside was breathable, like Earth's air three miles up, but with a bit more oxygen. Mars's air is far thinner, and poisonous. Clearly they were not of Mars.
The walls were thick and deeply eroded. They leaned inward against the internal pressure. The roof was somewhat thinner, just heavy enough for the pressure to support it. Both walls and roof were of fused Martian dust.
The heating system still worked—and it was also the lighting system: grids in the ceiling glowing brick red. The base was always ten degrees too warm. We didn't find the off switches for almost a week: they were behind locked panels. The air system blew gusty winds through the base until we fiddled with the fans.
We could guess a lot about them from what they'd left behind. They must have come from a world smaller than Earth, circling a red dwarf star in close orbit. To be close enough to be warm enough, the planet would have to be locked in by tides, turning one face always to its star. The aliens must have evolved on the lighted side, in a permanent red day, with winds constantly howling over the border from the night side.
And they had no sense of privacy. The only doorways that had doors in them were airlocks. The second floor was a hexagonal metal gridwork. It would not block you off from your friends on the floor below. The bunk room was an impressive expanse of mercury-filled waterbed, wall to wall. The rooms were too small and cluttered, the furniture and machinery too close to the doorways, so that at first we were constantly bumping elbows and knees. The ceilings were an inch short of six feet high on both floors, so that we tended to walk stooped even if we were short enough to stand upright. Habit. But Lear was just tall enough to knock his head if he stood up fast, anywhere in the base.
We thought they must have been smaller than human. But their padded benches seemed human-designed in size and shape. Maybe it was their minds that were different: they didn't need psychic elbow room.
The ship had been bad enough. Now this. Within the base was instant claustrophobia. It put all of our tempers on hair triggers.
Two of us couldn't take it.
Lear and Childrey did not belong on the same planet.
With Childrey, neatness was a compulsion. He had enough for all of us. During those long months aboard Percival Lowell, it was Childrey who led us in calisthenics. He flatly would not let anyone skip an exercise period. We eventually gave up trying.
Well and good. The exercise kept us alive. We weren't getting the healthy daily exercise anyone gets walking around the living room in a one-gravity field.
But after a month on Mars, Childrey was the only man who still appeared fully dressed in the heat of the alien base. Some of us took it as a reproof, and maybe it was, because Lear had been the first to doff his shirt for keeps. In the mess Childrey would inspect his silverware for water spots, then line it up perfectly parallel.
On Earth, Andrew Lear's habits would have been no more than a character trait. In a hurry, he might choose mismatched socks. He might put off using the dishwasher for a day or two if he were involved in something interesting. He would prefer a house that looked "lived in." God help the maid who tried to clean up his study. He'd never be able to find anything afterward.
He was a brilliant but one-sided man. Backpacking or skin diving might have changed his habits—in such pursuits you learn not to forget any least trivial thing— but they would never have tempted him. An expedition to Mars was something he simply could not turn down. A pity, because neatness is worth your life in space.
You don't leave your fly open in a pressure suit.
A month after the landing, Childrey caught Lear doing just that.
The "fly" on a pressure suit is a soft rubber tube over your male member. It leads to a bladder, and there's a spring clamp on it. You open the clamp to use it. Then you close the clamp and open an outside spigot to evacuate the bladder into vacuum.
Similar designs for women involve a catheter, which is hideously uncomfortable. I presume the designers will keep trying. It seems wrong to bar half the human race from our ultimate destiny.
Lear was addicted to long walks. He loved the Martian desert scene: the hard violet sky and the soft blur of whirling orange dust, the sharp close horizon, the endless emptiness. More: he needed the room. He was spending all his working time on the alien communicator, with the ceiling too close over his head and everything else too close to his bony elbows.
He was coming back from a walk, and he met Childrey coming out. Childrey noticed that the waste spigot on Lear's suit was open, the spring broken. Lear had been out for hours. If he'd had to go, he might have bled to death through flesh ruptured by vacuum.
We never learned all that Childrey said to him out there. But Lear came in very red about the ears, muttering under his breath. He wouldn't talk to anyone.
The NASA psychologists should not have put them both on that small a planet. Hindsight is wonderful, right? But Lear and Childrey were each the best choice for competence coupled to the kind of health they would need to survive the trip. There were astrophysicists as competent and as famous as Lear, but they were decades older. And Childrey had a thousand spaceflight hours to his credit. He had been one of the last men on the moon.
Individually, each of us was the best possible man. It was a damn shame.
The aliens had left the communicator going, like everything else in the base. It must have been hellishly massive, to judge by the thick support pillars slanting outward beneath it. It was a bulky tank of a thing, big enough that the roof had to bulge slightly to give it room. That gave Lear about a square meter of the only head room in the base.
Even Lear had no idea why they'd put it on the second floor. It would send through the first floor, or through the bulk of a planet. Lear learned that by trying it, once he knew enough. He beamed a dot-dash message through Mars itself to the Forward Mass Detector aboard Lowell.
Lear had set up a Mass Detector next to the communicator, on an extremely complex platform designed to protect it from vibration. The Detector produced waves so sharply pointed that some of us thought they could feel the gravity radiation coming from the communicator.