NEW EARTH

74.

“Four planets,” muttered Trevize. “All are small, plus a trailing off of asteroids. No gas giants.”

Pelorat said, “Do you find that disappointing?”

“Not really. It’s expected. Binaries that circle each other at small distances can have no planets circling one of the stars. Planets can circle the center of gravity of both, but it’s very unlikely that they would be habitable—too far away.

“On the other hand if the binaries are reasonably separate, there can be planets in stable orbits about each, if they are close enough to one or the other of the stars. These two stars, according to the computer’s data bank, have an average separation of 3.5 billion kilometers and even at periastron, when they are closest together, are about 1.7 billion kilometers apart. A planet in an orbit of less than 200 million kilometers from either star would be stably situated, but there can be no planet with a larger orbit. That means no gas giants since they would have to be farther away from a star, but what’s the difference? Gas giants aren’t habitable, anyway.”

“But one of those four planets might be habitable.”

“Actually the second planet is the only real possibility. For one thing, it’s the only one of them large enough to have an atmosphere.”

They approached the second planet rapidly and over a period of two days its image expanded; at first with a majestic and measured swelling. And then, when there was no sign of any ship emerging to intercept them, with increasing and almost frightening speed.

The Far Star was moving swiftly along a temporary orbit a thousand kilometers above the cloud cover, when Trevize said grimly, “I see why the computer’s memory banks put a question mark after the notation that it was inhabited. There’s no clear sign of radiation, either light in the night-hemisphere, or radio anywhere.”

“The cloud cover seems pretty thick,” said Pelorat.

“That should not blank out radio radiation.”

They watched the planet wheeling below them, a symphony in swirling white clouds, through occasional gaps of which a bluish wash indicated ocean.

Trevize said, “The cloud level is fairly heavy for an inhabited world. It might be a rather gloomy one. —What bothers me most,” he added, as they plunged once more into the night-shadow, “is that no space stations have hailed us.”

“The way they did back at Comporellon, you mean?” said Pelorat.

“The way they would in any inhabited world. We would have to stop for the usual checkup on papers, freight, length of stay, and so on.”

Bliss said, “Perhaps we missed the hail for some reason.”

“Our computer would have received it at any wavelength they might have cared to use. And we’ve been sending out our own signals, but have roused no one and nothing as a result. Dipping under the cloud layer without communicating with station officials violates space courtesy, but I don’t see that we have a choice.”

The Far Star slowed, and