The circling of Antarctica by the ships of Captain Cook in the 1770's, the discovery of Antarctic coasts in the 1840's by Dumont d'Urville, James Clarke Ross and Charles Wilkes, and the attainment of the South Pole on foot by parties under Roald Amundsen and Robert Fal­con Scott in 1911-12--all are landmarks in a living history of human exploration.

This history has reached another of its greatest cli­maxes with the first visit to the moon.

To those who ponder the values of such human achieve­ments, let me simply proclaim that rigid intellectual forms, matching rigid social structures, cannot last in the face of a surprising new fact. It was possible to contest Copernicus' ideas of a group of planets re­volving around the sun until Galileo's use of the tele­scope in studying the moon, and the moons of Jupiter, gave the theories of Copernicus unchallengeable em­pirical support. The work of Galileo, so intimately linked with the mountains of the moon, is a good candidate (among many) for the decisive event which launched the age culminating in a landing on the moon.

The immediate effect of such discoveries may be vanishingly small, even in the Apollo case when hundreds of millions watched it. A moon voyage may seem to count for no more than the fall of Icarus did to the painter Breughel, who depicted a very tiny splash in the midst of an immense landscape. Yet the splash oc­curred. The fact cannot be denied, and the exploration will continue--at however jerky a pace.

It is easy for an artist to mock the strivings of an Icarus. Explorers do not have an easy time giving words to their compulsion for searching out regions where nature shows its face in some extreme way, throwing light on the history and character of the planet on which we exist. Just why explorers, by their wanderings, should go on asking the question, "What is a Planet?" is not clear.

Antarctica, where few things exist except mosses, lichens, a few breeds of insects, seals, gulls and pen­guins, is one such region. The moon is another: lifeless, airless, waterless, lacking a magnetic field, of a different density from Earth, and now known to be covered with a layer of rather glassy dust. Neither Antarctica nor the moon have failed to produce their quota of surprises.

In such an extreme environment, many of the definitions of ordinary life must give way. Only an exceptional few can ever go to such a place. To live in a region of ex­tremes means insulation from the natural environment; human contact with the surroundings must be restricted, remote. Yet, in order to design the protective equipment, someone must know enough about the surroundings to imagine their effect. Man must be in sympathy with the surroundings--like Captain Nemo--or they will kill him. Nowhere are the penalties of an estrangement from nature more apparent than in a place like the moon.

Such voyages to the end of man's experience and into the beginning of space are only the physical embodi­ment of the modern age of mental exploration--the age of science. In such an age, a science like astronomy, which has modest practical importance for navigators, can open men's eyes to the existence of another world. And in a land where minds and ships can roam beyond the reach of authority, tyrannical forms cannot endure.

Victor K. McElheny returned from his assignment in Britain as European Editor of Science in 1967 to become Science Editor of the Boston Globe at least in part so as to have first-hand experience with what he has called man's "majestic" effort to reach the moon and outer space. Since his retirement in 1998 McElheny has published two books, Insisting on the Impossible: The Life of Edwin Land and Watson and DNA: Making a Scientific Revolution. He is currently working on a book about the Human Genome Project.