Early pulp science fiction was often adventure stores for boys, with dashing, square-jawed captains defeating evil aliens and bedding grateful alien women. Even when scientists were heroes, they solved the mysteries of the universe. As the genre matured, writers started exploring different kinds of stories. Arthur C. Clarke infused his writing with spirituality. His best stories, like 2001: A Space Odyssey or Childhood’s End, often deal with technology and higher intelligence aiding humanity into the next step of our evolution. Rendezvous with Rama fits that same idea, but instead of being elevated, humanity is merely teased.

One hundred year in the future, an asteroid detection system discovers alien craft entering the solar system. No one knows where these ships ultimately come from or where they’re going, or how they work, or even their purpose. Naming them after Hindu Gods, scientists discover one of them, dubbed Rama, will pass close enough to the earth for a craft to intercept it. So the bulk of the novel is these astronauts entering and exploring this alien craft.

The exploration of Rama, trying to understand its mysteries, is the the central conflict. There’s no alien invasion or robot uprising – just an automated spacecraft with an artificial environment lining its hollow interior. The astronauts are professionals, and the novel’s measured style reflects that. Clarke describes in detail how the astronauts enter the enormous craft, establish base camps, and study and map the craft. It’s a tribute to the process and difficulties of understanding the potentially unknowable.

For all the complaints about aliens in science fiction not being alien enough, Rama is utterly opaque. The scientists and engineers who board it can catalogue and describe what happens inside, but they cannot explain any of it. In a sense, this might make it the most honest science fiction novel, because we are frequently in the same position. As much as we can analyse the universe and break it down into mathematical constructs, the why of it all remains elusive. It’s science fiction about the limits of science. Nothing we have can crack the mysteries of Rama – it merely is, and we must be content with that.