Hot Planet drops a scientific expedition onto a Mercury that refuses to stay still. The crew of the Albireo has already endured constant earthquakes when a black column rises beyond the nearby mountains. At first it is exactly what scientists travel across space hoping to find. Then lava begins moving toward the ship, tractors are scattered across the planet, and some of the crew cannot even be reached by radio.
Hal Clement makes the danger feel convincing because his characters respond like working scientists rather than conventional heroes. They measure temperatures, study the terrain, improvise with the equipment they brought and argue their way toward practical solutions. But Mercury keeps changing faster than their calculations, and getting everyone back to the Albireo may require an idea no mission plan anticipated.
Hal Clement was the pen name of Harry Clement Stubbs, born in Massachusetts in 1922. He studied astronomy at Harvard and earned degrees in education and chemistry, later spending decades teaching science. During World War II he served as a B-24 pilot and copilot, flying combat missions over Europe before continuing his military service in the Air Force Reserve.
Clement became one of the defining writers of hard science fiction, building stories around real scientific problems and letting his characters reason their way through them. His best-known novel, Mission of Gravity, was serialized in Astounding Science Fiction in 1953 and became a landmark of the genre. In Hot Planet, that same approach turns Mercury itself into the problem: observe carefully, think quickly—and hope the planet gives you enough time.
