HOT PLANET By HAL CLEMENT Illustrated by FINLAY [Transcriber's Note: This etext was produced from Galaxy Magazine August 1963. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] Mercury had no atmosphere--everyone knew that. Why was it developing one now? I The wind which had nearly turned the _Albireo's_ landing into a disaster instead of a mathematical exercise was still playing tunes about the fins and landing legs as Schlossberg made his way down to Deck Five. The noise didn't bother him particularly, though the endless seismic tremors made him dislike the ladders. But just now he was able to ignore both. He was curious--though not hopeful. "Is there anything at all obvious on the last sets of tapes, Joe?" Mardikian, the geophysicist, shrugged. "Just what you'd expect ... on a planet which has at least one quake in each fifty-mile-square area every five minutes. You know yourself we had a nice seismic program set up, but when we touched down we found we couldn't carry it out. We've done our best with the natural tremors--incidentally stealing most of the record tapes the other projects would have used. We have a lot of nice information for the computers back home; but it will take all of them to make any sense out of it." Schlossberg nodded; the words had not been necessary. His astronomical program had been one of those sabotaged by the transfer of tapes to the seismic survey. "I just hoped," he said. "We each have an idea why Mercury developed an atmosphere during the last few decades, but I guess the high school kids on Earth will know whether it's right before we do. I'm resigned to living in a chess-type universe--few and simple rules, but infinite combinations of them. But it would be nice to know an answer sometime." "So it would. As a matter of fact, I need to know a couple right now. From you. How close to finished are the other programs--or what's left of them?" "I'm all set," replied Schlossberg. "I have a couple of instruments still monitoring the sun just in case, but everything in the revised program is on tape." "Good. Tom, any use asking you?" The biologist grimaced. "I've been shown two hundred and sixteen different samples of rock and dust. I have examined in detail twelve crystal growths which looked vaguely like vegetation. Nothing was alive or contained living things by any standards I could conscientiously set." Mardikian's gesture might have meant sympathy. "Camille?" "I may as well stop now as any time. I'll never be through. Tape didn't make much difference to me, but I wish I knew what weight of specimens I could take home." "Eileen?" Mardikian's glance at the stratigrapher took the place of the actual question.