A City on Mercury Must Stay on the Dark Side

Terminator rolls around Mercury just like its sunwalkers, moving at the speed of the planet’s rotation, gliding over twenty gigantic elevated tracks, which together hold aloft and push west a town quite a bit bigger than Venice. The twenty tracks run around Mercury like a narrow wedding band, keeping near the forty-fifth latitude south, but with wide detours to south and north to avoid the worst of the planet’s long escarpments. The city moves at an average of five kilometers an hour. The...

 Mercury Sun Walkers

The sun is always just about to rise. Mercury rotates so slowly that you can walk fast enough over its rocky surface to stay ahead of the dawn; and so many people do. Many have made this a way of life. They walk roughly westward, staying always ahead of the stupendous day. Some of them hurry from location to location, pausing to look in cracks they earlier inoculated with bioleaching metallophytes, quickly scraping free any accumulated residues of gold or tungsten or uranium. But most of them...