The Secret of the Ninth Planet

While the circumnavigation of the solar system seems farfetched, it may not be once the problem of effective anti-gravitational control is solved. In this book I have assumed that the many researchers now actually at work on this problem will achieve such a result in the next decade. It is not at all impossible that they may--for we all know that the more minds that work at a problem, the sooner it will be solved. The discovery of a means of negating, reversing or otherwise utilizing the immense force of gravitation for space flight purposes is now thought to be within the bounds of probability. It should occur some time within the next hundred years, possibly in even the short period I assume here.

Once solved, the severe handicaps imposed on space exploration by the weight and chemical limitations of rockets would no longer apply. The whole timetable of our conquest of the planets in our solar system would be tremendously speeded up, from hot Mercury all the way out to frigid Pluto.

In describing the visits of the spaceship Magellan to the planets, I have endeavored to adhere to known facts and the more reasonable assumptions about each of these worlds. The planet Pluto, however, deserves further comment, occupying as it does both an important role in this adventure and a unique one in actual astronomical lore.

Back at the dawn of this century, many astronomers, and notably Dr. Percival Lowell, studied certain irregularities in the orbit and motion of Neptune, at that time believed to be the outermost planet. They decided that these eccentricities (or perturbations, as they are called) could only be caused by the presence of another, yet undiscovered planet beyond Neptune.

Following this line of research, a young astronomer, Dr. Clyde Tombaugh, working at Lowell's own observatory, was able to announce on March 13, 1930, that he had finally found this ninth world, which he named Pluto.

In the years that have followed, Pluto has proven to be a truly puzzling planet. Unlike its neighbors from Jupiter outward, it is not a giant world, light and gaseous in nature. Instead, it belongs physically to the small, dense inner planets of which Earth is one.

The latest viewpoint on this planet, whose size and weight seem quite like those of Earth, is that it may not be a true child of the Sun, but an outsider captured as it roamed the trackless realms of galactic space. Its orbit is highly eccentric and rather lopsided, taking it as far away from the Sun as four and a half billion miles and as close to the Sun as two and three-quarter billion miles, thereby cutting inside the orbit of Neptune itself. In fact, during the period from 1969 to 2009 (covering most of the lifetimes of the younger readers of this book) Pluto will not be the ninth planet, but the eighth, for it will be at its closest in those years. Huge Neptune will thus regain temporarily the title of being the Sun's farthest outpost!

This orbital eccentricity has lead some astronomers to speculate on the possibility that Pluto may once have been briefly held as a satellite of Neptune. And following that line of thought, the possibility also has been suggested that Neptune's larger moon, Triton, may once have been a companion of Pluto which failed to break away from Neptune's grip!