"Temperature's up though. Ninety-three. And a seventy-seven percent humidity."
He left them and walked down across the rocks to the ocean's edge. Two young girls were down there before him, sampling the water, running both chemical and biological probing tests.
"Hello, Mr. McCann," the taller girl said dully. "Want our report?"
"Found anything?" He knew already that there was nothing to find. If there were life the instruments would have recorded its presence.
"No. Water temperature eighty-six. Sodium chloride four-fifths Earth normal." She looked up, surprised. "Why so low?"
"More water in the ocean, maybe. Or maybe we've had a nova since we were here last."
It was getting late, almost sunset. Soon it would be time for the photographic star-charts to be made. Hugh brought himself up short and smiled bitterly. He too was in the grip of habit. Still, why not? Perhaps they could estimate, somehow, how many millions of years had passed.
Why? What good would it do them to find out?
After a while the sun set and a little later the full moon rose, hazy and indistinct behind the clouds of water vapor. Hugh stared at it, watched it rise higher until it cleared the horizon, a great bloated bulk. Then he sighed and shook his head to clear it and started to work. The clouds were thick. He had to move the screening adjustment almost to its last notch before the vapor patterns blocked out and the stars were bright and unwavering and ready to be photographed. He inserted the first plate and snapped the picture of the stars whose names he knew but whose patterns were wrong, some subtly, some blatantly.
There was something he was overlooking. Some other factor, not taken into account. He developed the first plates and compared them with the star charts of Earth as it had been before they left it, and he shook his head. Whatever the factor was, it eluded him. He went back to work.