Enlarge (credit: Arch Mission Foundation)

With any luck, alien civilizations will one day be able to read the works of Isaac Asimov and tap into his imagined Encyclopedia Galactica. That’s the hope, anyway.

Tesla wasn’t shy about advertising its launch of a Tesla Roadster on board a Falcon Heavy rocket, on Tuesday. But it was less vocal about that Roadster’s secret cargo: a tiny optical disc, known as an Arch (pronounced “ark”). Theoretically, this format of disc can hold 360TB per disc, and the one on board the launched car contains Asimov’s Foundation book trilogy.

Unlike traditional optical discs, according to the Arch Mission’s press release, this Arch disc is “written by a femtosecond laser on quartz silica glass,” and its data is “encoded digitally as 20nm gratings, formed by plasma disruptions from the laser pulses.”