In their quiet, fictional way, hobbits and ents arrived at Mercury this month. They stole no headlines from Curiosity's successful touchdown on Mars as they slipped into their newfound niche, Crater Tolkien, on the Solar System's innermost planet. Crater Tolkien came to light thanks to the year-plus explorations of the Mercury-orbiting spacecraft called MESSENGER (an acronym for MErcury Surface, Space ENvironment, Geochemistry and Ranging). The MESSENGER science team followed accepted planetary nomenclature protocol when it suggested author J.R.R. Tolkien's name for one of nine new crater finds. All impact craters on Mercury recall past artists, whether they expressed themselves in paint, print, song, or other creative medium.
Crater Tolkien, not exactly a hobbit hole, lies in shadow near Mercury's north pole and appears to contain deposits of ice. The notion of frozen water on the surface of a world so close to the Sun sounds as strange as the doings in Middle Earth, yet planetary scientists were not surprised by the discovery. Radar studies had identified ice-bright patches inside some of the planet's craters even before MESSENGER began circling Mercury in March 2011. Unlike the Earth or Mars, Mercury hardly tilts at all, so its polar regions receive no direct light. And even though the Sun warms up Mercury's day side to several hundred degrees, the rarefied atmosphere fails to distribute that heat.
While The Hobbit is generally considered a children's fantasy tale, I read it as a textbook in a university-level course on English syntaxat the City College of New York. My professor believed it possible to discover the hidden ice of an author's style by analyzing his sentence structure. The six or seven students enrolled with me in the seminar divided up The Hobbit's chapters. Between us we diagrammed every sentence, beginning with the one that came unbidden to Tolkien while he graded student examination papers at Oxford: "In a hole in the ground there lived a hobbit."
Extending human naming tendencies to the other planets may seem frivolous, but it gives scientists a straightforward way to refer to specific features in their published papers and conference presentations. The practice also reinforces age-old links between scientific inquiry and other forms of creative curiosity.