or 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!

I think that the first men to land on Pluto are going to make some very
astonishing discoveries. But I am also sure that they will never go
there in rockets. They will have to make the immense trip by some more
powerful means--like the anti-gravitational drive.

D.A.W.

_The Secret of the Ninth Planet_

Chapter 1. _Special Delivery--by Guided Missile_

On the morning that the theft of the solar system's sunlight began, Burl
Denning woke up in his sleeping bag in the Andes, feeling again the
exhilaration of the keen, rarefied, mountain air. He glanced at the
still sleeping forms of his father and the other members of the Denning
expedition, and sat up, enjoying the first rays of the early morning.

The llamas were already awake, moving restlessly back and forth on their
padded feet, waiting for their tender to arise and unleash them. The
mules were standing patiently as ever, staring quietly into the distant
misty panorama of the mountains.

It was, thought Burl, a dim day, but this he supposed was due to the
earliness of the morning. As the Sun rose, it would rapidly bring the
temperatures up, and its unshielded rays would force them to cover up as
they climbed along the high mountain passes.

The sky was cloudless as usual. Burl assumed that the dimness was due to
volcanic dust, or some unseen high cloud far away. And, indeed, as the
expedition came to life, and the day began in earnest, nobody paid any
attention to the fact that the Sun was not quite so warm as it should
have been.

The Denning expedition, questing among the untracked and forgotten
byways of the lost Inca ruins in the vast, jagged mountains of inland
Peru, was not alone in failing to notice the subtle channeling away of
the Sun's warmth and brilliance. They were, in this respect, one with
virtually the entire population of Earth.

In New York, in San Francisco, in Philadelphia and Kansas City, people
going about their day's chores simply assume