Michael Swanwick's Periodic Table of Science Fiction

Mercury

200.59

The Outriders

We are the outriders of Quicksilver City. We ride ahead, sunward, forever

maintaining a temperature thirty degrees hotter than the city that

follows us. Our job is to scout out the Mercurial terrain for landslides,

crevasses, and anything else that might hinder the city in its eternal

journey around the planet. Ahead of us, the robot mines and smelters,

factories and warehouses wake from hibernation as they fall out of the

blistering heat of noon. After radio consultation with the

autocomptrollers of Quicksilver City, they disgorge the raw materials the

city will need this cycle.

Meanwhile, we blast, grade, and level. When we hit a scarp, out come the

mini-nukes and down goes the rock. When we come to a crevasse, we fill it

in. The city arrives to find a gentle ramp or level ground, and all of us

outriders gone, long gone on our unending voyage into the sun.

We were only a few hundred scientists suddenly stranded on a single

mobile research station when civilization fell and Earth was destroyed.

Not everyone thought we would survive. But we had the tools! We had the

determination! Now Quicksilver City is a congeries of a thousand great

buildings, all speeding around and around the planet, tenaciously staying

in the human comfort range, growing, thriving, and above all never

stopping.

Here are the plain facts. The maximum surface temperature on Mercury is

427° C. Because there's no atmosphere worth speaking of to retain that

heat, at night the surface temperature plunges to a minimum of -173° C.

Machines can sleep through the hot times and the cold. Human beings

can't. So we have to keep on the move.

Mercury is roughly the size of Earth's moon and a day here, from dawn to

dusk, is 176 Earth days long. Which makes it possible to move fast enough

to outrun the sunset. But the planet's rotation is almost perpendicular

to the orbital plain, so Quicksilver City can't just keep plodding the

same circular path over and over. Every rotation is different, a new set

of challenges, something unexpected to be overcome.

So we ride. It all comes down to us?the outriders and pioneers. We ride

and blast and curse and sweat, and we know that we're the final and only

hope that humanity has. That the human race is always and perpetually one

day's bad luck away from extinction.

But when has it ever been different?

The End