Jupiter Read online

  “When I was a little boy I read astronomy books. I also read science fiction. Astronomy books told me a few facts about Jupiter, but not many of the intimate details. Few intimate details were known in the prehistoric times in which I was a boy. Besides I preferred what the science-fiction tales said concerning Jupiter …

  —Isaac Asimov (from his Introduction)

  What with all the Pioneer probes headed for that giant and mysterious planet, it won’t be long before we find out everything we ever wanted to know about Jupiter —well, almost everything! Meanwhile, let’s see how nine of our own pioneers in science fiction imagined the planet.

  Titles by

  FREDERIK POHL

  Short Stories THE GOLD AT THE STARBOW’S END

  ALTERNATING CURRENTS

  THE CASE AGAINST

  TOMORROW TOMORROW TIMES SEVEN

  THE MAN WHO ATE THE WORLD

  TURN LEFT AT THURSDAY

  THE ABOMINABLE EARTHMAN

  DIGITS AND DASTARDS

  DAY MILLION

  Novels SLAVE SHIP

  EDGE OF THE CITY

  DRUNKARD’S WALK

  A PLAGUE OF PYTHONS

  THE AGE OF THE PUSSYFOOT

  In collaboration with C. M. KORNBLUTH

  THE SPACE MERCHANTS

  SEARCH THE SKY

  GLADIATOR-AT-LAW

  WOLFBANE

  THE WONDER EFFECT

  In collaboration with JACK WILLIAMSON

  THE REEFS OF SPACE

  STARCHILD

  ROGUE STAR

  UNDERSEA CITY

  UNDERSEA FLEET

  UNDERSEA QUEST

  Anthologies THE STAR SERIES (No. 1 through No. 6)

  STAR OF STARS

  NIGHTMARE AGE

  All published by Ballantine Books

  JUPITER

  Edited by Carol and Frederik Pohl

  Introduction by Isaac Asimov

  BALLANTINE BOOKS • NEW YORK

  Bridge, by James Blish, copyright © 1952 by Street & Smith Publications, Inc. Reprinted by permission of the author’s agent, Robert P. Mills, Ltd.

  Victory Unintentional, by Isaac Asimov, copyright © 1942 by Fictioneers, Inc., copyright renewed 1969 by Isaac Asimov. Reprinted by permission of the author.

  Desertion, by Clifford D. Simak, copyright © 1944 by Street & Smith Publications, Inc., copyright renewed 1972 by Clifford D. Simak. Reprinted by permission of the author’s agent, Robert P. Mills, Ltd.

  The Mad Moon, by Stanley G. Weinbaum, copyright © 1934 by Street & Smith Publications, Inc. Reprinted by permission of the author’s agent, Forrest J. Ackerman.

  Heavy planet, by Milton A. Rothman, copyright © 1939, by Street & Smith Publications, Inc. Reprinted by permission of the author.

  The Lotus-Engine, by Raymond Z. Gallun, copyright © 1940 by Fictioneers, Inc. Reprinted by permission of the author’s agent, Forrest J. Ackerman.

  Call Me Joe, by Poul Anderson, copyright © 1957 by Street & Smith Publications, Inc. Reprinted by permission of the author’s agent, Scott Meredith Literary Agency, Inc.

  Habit, by Lester del Rey, copyright © 1939 by Street & Smith Publications, Inc. Reprinted by permission of the author’s agent, Scott Meredith Literary Agency, Inc.

  A Meeting with Medusa, by Arthur C. Clarke, copyright © 1971 by Playboy. Reprinted by permission of the authors agent, Scott Meredith Literary Agency, Inc.

  Copyright © 1973 by Carol and Frederik Pohl

  Introduction Copyright © 1973 by Isaac Asimov

  All rights reserved under International and Pan-American Copyright Conventions.

  SBN 345-23662-9-125

  First Printing: December 1973

  Printed in Canada.

  Cover art by John Berkely

  BALLANTINE BOOKS, INC.

  201 East 50th Street, New York, N.Y. 10022

  Contents:

  JUPITER THE GIANT - Introduction

  JUPITER AT LAST - Preface

  BRIDGE - James Blish

  VICTORY UNINTENTIONAL - Isaac Asimov

  DESERTION - Clifford D. Simak

  THE MAD MOON - Stanley G. Weinbaum

  HEAVYPLANET - Milton A. Rothman

  THE LOTUS-ENGINE - Raymond Z. Gallun

  CALL ME JOE - Poul Anderson

  HABIT - Lester del Rey

  A MEETING WITH MEDUSA - Arthur C. Clarke

  JUPITER THE GIANT

  Introduction

  When I was a little boy I read astronomy books. I also read science fiction. Astronomy books told me a few facts about Jupiter, but not many of the intimate details. Few intimate details were known in the prehistoric times in which I was a boy. Besides, I preferred what the science-fiction tales said concerning Jupiter, and in many of them Jupiter was an inhabited world not terribly different from Earth, except that it might be the haunt of space pirates or intelligent insects.

  The truth dawned on me not through more careful reading of more up-to-date astronomy books, but through that remarkable phenomenon, John W. Campbell, Jr. Even before he became an editor and single-handedly turned science fiction into a mature and rational branch of literature, he was educating us with a scries of astronomical articles for Astounding Stories. These taught me, for the first time, that science could be as fascinating as science fiction.

  The best article in the series was “Other Eyes Watching” in the February 1937 issue. It was about Jupiter and never again did I think of Jupiter as anything but what it more or less was.

  In fact, the second story I wrote (in 1938) dealt with Jupiter’s satellite system, and in writing it I used some of the views I had read in Campbell’s article a year and a half earlier. I sold that second story to none other than Fred Pohl, the male half of the editorial team of this anthology. He published it under the title of “The Callistan Menace” in the April 1940 issue of Astonishing Stories.

  I doubt that any self-respecting science-fiction writer would nowadays write any story about Jupiter that didn’t take into account what we know (or think we know) about the planet—as this anthology demonstrates. Naturally, then, we are all fascinated by the new knowledge that the space age may be on the point of bringing us.

  As I write this, the space-probe Pioneer 11 has taken off from Cape Kennedy in a long-drawn-out flash of blazing orange light. Beyond the atmosphere it reached a speed of nine miles a second, and it passed the Moon after eleven hours of flight. Some time in February 1975, it will pass near Jupiter.

  But it will be only the second probe to pass that planet. Ahead of it is Pioneer 10, which took off on March 2, 1972, and has passed safely through the asteroid belt (as I write this) and is still transmitting. It will reach Jupiter on December 3, 1973 (about the time this book is published), and will pass only 85,000 miles from the planet’s surface—still transmitting, if all goes well.

  Whipping about the giant planet, Pioneer 10 will gain enough speed to break out of the Sun’s gravitational grip and go skittering past the orbits of all the outer planets. In 1984 it will pass beyond Pluto, and will continue farther still.

  Pioneer 10 will be the first man-made object ever to leave the solar system. It will be moving in the direction of the star Aldebaran and will reach the neighborhood of that star (or the neighborhood where it now is) in about 1,700,000 years.

  On Pioneer 10 is a message from Earth, etched into a 6-by-9-inch gold-covered aluminum slab. It is not an ordinary message, but a mixture of figures and symbols that could be properly interpreted only by sophisticated astronomers of the type we would expect in any society advanced enough to detect the small probe in space and to pluck it out of emptiness—millions of years from now, if ever.

  But Pioneer 10 (and Pioneer 11, too if it follows in the tracks of the earlier probe) will have ceased t
ransmitting long before it leaves the solar system. What will happen to it after it passes Jupiter we will never know. But that doesn’t matter. All we ask of it is to tell us something of the environment it encounters as it speeds by Jupiter and its twelve satellites.

  How strong are the radiation belts around Jupiter? What is the strength of its magnetic field? How many particles does it encounter? How strong are the pulls of Jupiter’s satellites? What is the appearance of the satellites’ surfaces? What is the appearance of Jupiter’s cloud cover at close range? Its colors? Its movement? Its chemistry? Its temperature?

  Question mark, question mark, question mark…

  And why do we want to know?

  Because Jupiter is different, enormously different, and we don’t know what to make of it.

  We live on a planet, and we know its characteristics. There are other planets in the solar system that are essentially like Earth—different in detail, but Earth-like overall. And since we know about the Earth, we automatically know something about them.

  We have landed on our sister-world, the Moon. It is smaller than Earth and has neither air nor water, but its soil and rocks are not very different from those of Earth. And the scenery of the Moon could be similar to that in some areas of the Earth if you allow for the lack of air and water.

  We have seen Mars close up, and it is different in detail from the Moon and Earth, but there is a broad similarity, too. We have touched the surface of Venus with several Soviet probes and with radar waves, and it, too, is rough and hard and mountainous.

  And Mercury, no doubt, and the asteroids, and the satellites of the various planets—All different in detail, but all members of the same species. That Earth is sufficiently different to support life is the result of the accident that it is the largest of all these bodies and is at a distance from the Sun that allows water to remain liquid.

  Among all the bodies circling the Sun, there are only four that do not belong to Earth’s species, but to a different species altogether. These four are Jupiter, Saturn, Uranus, and Neptune, and the reason they are of a different species is that they are much larger than Earth—so much larger that they form in a different way and end with a different composition and nature.

  Of them all, Jupiter is the largest and therefore the most extreme in its differences. It is the one closest to the Sun, so that it receives more energy from solar radiation and is more violently stormy than the rest, and also the one closest to us, so that it is most easily examined.

  To study this other species of planet, we must study Jupiter.

  Of course, though it is closest to us of any of its kind, it is still not very close. At its closest, Jupiter is nearly 400.000,000 miles from us—sixteen hundred times as far away as the Moon, four times as far away as the Sun. Is it any wonder the probes take nearly two years to reach it?

  And it really is a giant.

  It has a diameter a little over eleven times that of the Earth. In other words, if you place eleven bodies like the Earth side by side, they won’t quite stretch across the width of Jupiter. That’s the usual way of comparing planetary sizes, but it doesn’t begin to show the difference.

  Jupiter’s surface area is 125 times that of the Earth. If you imagine the surface of the Earth peeled off and flattened out and pasted on the surface of Jupiter, it would cover about half as much of that planet as the United States does of the Earth.

  And if you consider volumes, Jupiter is fourteen hundred times as large as the Earth.

  Of course, Jupiter isn’t as well packed as Earth is. Although it has fourteen hundred times as much room as Earth has in which to pack away matter, it has only 318 times the mass of Earth. That’s enough, to be sure, since it means that Earth is to Jupiter as your weight is to that of two African elephants, of the largest size, put together.

  Jupiter’s mass is enough to hold a far-flung system of satellites to itself. One of those satellites, Jupiter-VIII, can recede to a distance of 20 million miles from Jupiter—eighty times as far as the Moon is from Earth—without breaking away. Four of the satellites are Moon-sized or larger. The largest, Ganymede, is larger than the planet Mercury.

  The nearest of the four large satellites, Io, is exactly as far from the center of Jupiter as the Moon is from the center of Earth (and it is almost exactly the size of the Moon, too). Earth’s relatively feeble gravity, however, can only drive the Moon into a motion of five-eighths of a mile per second, so that it does not complete its circle about the Earth for over twenty-seven days. Io, driven by Jupiter’s colossal gravity, moves at nearly eleven miles per second and circles Jupiter in less than two days.

  Everything about Jupiter is big and lavish.

  Well, not everything. Its density is small because, as aforesaid, there is only three hundred times Earth’s mass spread out through fourteen hundred times Earth’s volume. Jupiter’s density is only one-quarter that of Earth.

  That alone should tell us that Jupiter does not belong to the same species as Earth. If Jupiter had anything like the chemical composition of Earth, its gigantic gravitational field would pull it together so as to make it considerably denser than Earth.

  To be less dense than Earth despite the pull of its gravity, Jupiter must be made up largely of materials less dense than those that make up Earth, materials common enough in the Universe to be found in quantities sufficient to build a giant planet.

  This leaves us with one possibility only—hydrogen, together with a few minor impurities such as helium, neon, carbon, nitrogen, and oxygen. Helium and neon don’t react with any other substances but exist only as single, standoffish atoms. Anything else must combine with the overwhelming quantities of hydrogen. Carbon, nitrogen, and oxygen must exist as methane (CH4), ammonia (NH3), and water (H20).

  And that’s what we find. In the last half century, astronomers have slowly gathered evidence to show that Jupiter’s atmosphere is largely hydrogen, with admixtures of helium and probably neon, plus some methane and ammonia. (Water is undoubtedly present also, but is frozen solid somewhere below.)

  Yet it is an odd atmosphere, filled with cloud banks through which we cannot see. And the clouds have colors, even though none of the constituents we can detect are colored.

  There is a great elliptical spot in Jupiter’s atmosphere that never goes away. Its color darkens and fades; and since it seems reddish when it is dark, it is called the Great Red Spot. The Great Red Spot is about thirty thousand miles wide in its long diameter, eight thousand miles wide in the other, and has a surface area just about equal to that of the Earth.

  Nor is it fixed to the surface. It doesn’t move north or south, but it does move east or west. It sometimes gains or loses a whole lap on the rest of the planet.

  Well, what is the Great Red Spot? Why is it red? Why does the color grow darker and lighter? Why does it move about relative to other parts of the planet? Why does it move east and west but not north and south?

  No one knows.

  For that matter, why are there colors in the rest of the atmosphere? Why do the colors concentrate in certain dark bands with lighter areas between? What are the various light spots that form, and why do they come and go whereas the Great Red Spot is apparently permanent?

  No one knows.

  For that matter, how deep is the atmosphere of Jupiter? Does its composition remain the same as one penetrates deeper? If it changes, how does it change? Is there a solid surface under the atmosphere? If so, how far under, and what is it made of? What is it like at Jupiter’s core?

  And how strong are the winds? What kind of storms are there? Is there lightning? What is the temperature in the depths of the atmosphere? Does the atmosphere trap enough solar radiation to make the temperature fairly mild in the depths? Warm enough to allow an ocean of water and ammonia? And if so, can life develop in such an ocean?

  No one knows.

  Jupiter has an enormous magnetic field. How does that affect the space around it? How did it originate? Why do the radio waves issue i
n bursts that seem to have a timing related to the position of Io in its orbit?

  No one knows.

  And no one will ever know if all our data is derived only from our knowledge of Earth, Moon, Mars, and other members of our species of world.

  Jupiter is of a different species and probably one that is quite common in the Universe. Delicate wobblings of six small nearby stars seem to be the result of an asymmetric center of gravity imposed on those stars by planets circling them that are as large or even larger than Jupiter. Perhaps any star with a planetary system has one or more Jupiters. Perhaps there are more Jupiters than Earths in the Universe.

  Of course, as in almost everything else that calls for speculation, science-fiction writers have been there first. The strange and utterly alien world of Jupiter is a challenge to be met and writers willing to respond are not lacking. The challenge has been met in a variety of ways and in this book a broad sampling is spread out for your delectation.

  And if you should want to compare the pictures you see drawn here with what is actually known of Jupiter, I refer you (if I may be permitted an unabashed plug) to my lx)ok Jupiter, the Largest Planet, published by Lothrop in 1973.

  And let me add a personal note about the man-and-wife team (or woman-and-husband, in view of the times) that is editing this anthology. I have known and loved Fred and Carol Pohl for many years and I must tell you that, on the average, they are an extraordinarily good-looking couple. This is true despite the fact that Fred himself drags down that average about two miles.

  —Isaac Asimov

  JUPITER AT LAST

  Preface

  In December, 1972, we were part of a strange and delightful odyssey aboard the S.S. Statendam, cruising off the shores of Florida to watch the Apollo 17 launch, going on to visit the sin spots of the (how can they say it?) Virgin Islands and the big radio telescope in Puerto Rico. Among the crew were Carl Sagan and his pretty artist-wife Linda. They were only two of a marvelous ship’s company—Ted Sturgeon, Bob Heinlein, Marvin Minsky the robot man, Hugh Downs the TV man, Norman Mailer the man’s man, and so many others that to list them would be plain name-dropping. But the Sagans were a very special two. Carl is a remarkable person, sort of a volunteering encyclopedia with charm. (I had given a paper on population limits to the nonstop scientific symposium that was part of the cruises entertainment, and in it quoted some energy-consumption estimates. Carl called me on them after I was through. With some disdain I quoted my source, and Carl said, “I know, he got those figures from me and didn’t quite understand them.”) In a ship’s company that included at least a dozen certifiable geniuses, Carl Sagan was the one to whom difficult questions were referred for final decision.