July 20

The plain was the color of dried blood, strewn with stones no eye had ever counted, and on July 20, 1976, a metal footpad came to rest on it without a sound anyone could hear. Viking 1 had touched the surface of Mars — the first American craft to land and work on the face of another planet — and from that flat red distance it began sending back the look of a world. There was no one there. That is the strange grandeur of the thing: a machine standing alone on ground that had waited the whole length of the solar system for a visitor, and the visitor, when it came, was a camera and a sampling arm and a patience built out of human nerve.

It is the kind of arrival July 20 seems to specialize in. The date has a long habit of gathering people who went where no one had stood before, and it does not much care whether the frontier is a planet, a peak, or the hidden grammar of a living thing. Edmund Hillary was born on this date in 1919, the New Zealand mountaineer who would put his boot on the summit of Everest and look down on every other height on earth. Gregor Mendel was born July 20, 1822, the Austrian monk who knelt in a monastery garden among pea plants and read, in the ratios of wrinkled and smooth, the hidden architecture of heredity that no one had known was there to be read. Different summits, the same instinct — the reach past the known rim of the world.

The thread runs back further than the telescope or the rope. Petrarch was born on July 20, 1304, the Italian poet and scholar whose restless climb out of the medieval mind, his appetite for the lost voices of antiquity, helped pull the door open on the Renaissance. He was a man who literally climbed mountains to see, and then climbed the harder slope of an old certainty to see past it. The footpad on the Martian plain and the scholar bent over a recovered manuscript are doing, at bottom, the same human thing: pressing a hand against the edge of what is settled to find out what gives.

Even the date’s lesser frontiers keep the pattern. In 1906, Finland ratified an electoral law that made its women the first in Europe to win the equal right to vote — a boundary of a different kind, crossed for good. And in 1997 the restored USS Constitution, Old Ironsides, sailed again under her own canvas for the first time in 116 years, an old hull reaching back out toward open water. It would be conspicuous, on this of all dates, not to note that human beings first walked on the Moon on July 20 as well. The appetite is always the same one. July 20 simply keeps reminding us how badly we want the edge, and how far we will go, alone if we must, to stand on the far side of it.