Read "The Hitchhiker's Guide to the Galaxy" by Douglas Adams online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
On this particular Thursday, something was moving quietly through the ionosphere many miles above the surface of the planet; several somethings in fact, several dozen huge yellow chunky slablike somethings, huge as office blocks, silent as birds. They soared with ease, basking in electromagnetic rays from the star Sol, biding their time, grouping, preparing.
The planet beneath them was almost perfectly oblivious of their presence, which was just how they wanted it for the moment. The huge yellow something went unnoticed at Goon-hilly, they passed over Cape Canaveral without a blip, Woomera and Jodrell Bank looked straight through them, which was a pity because it was exactly the sort of thing they'd been looking for all these years.