The Universe appears to be a device contrived for the perpetual astonishment of astronomers.

Arthur C. Clarke (1917-2008) British writer

How the World Was One: Beyond the Global Village, Part 4, ch. 27 (1992)
    (Source)

A number of variants can be found, e.g., "I sometimes think the universe is a machine designed for the perpetual astonishment of astronomers" or "The universe: a device contrived for the perpetual astonishment of astronomers." The above is the only one I could find from a source by Clarke himself.