Isaac Asimov
Lucky Starr And The Big Sun Of Mercury
To Robyn Joan, who did her best to interfere.
Preface
Back in the 1950s, I wrote a series of six derring-do novels about David "Lucky" Starr and his battles against malefactors within the Solar System. Each of the six took place in a different region of the system, and in each case I made use of the astronomical facts – as they were then known.
Now, a quarter-century later, Fawcett is bringing out the novels in new editions; but what a quarter-century it has been! More has been learned about the worlds of our Solar System in this last quarter-century than in all the thousands of years that went before.
LUCKY STARR AND THE BIG SUN OF MERCURY was written in 1955 and at that time, astronomers were convinced that Mercury presented only one face to the Sun, and that it rotated on its axis in 88 days, which was exactly the length of the year. I made that conviction a central part of the plot of the book.
In 1965, however, astronomers studied radar-beam reflections from the surface of Mercury and found, to their surprise, that this was not so. Mercury rotates on its axis in 59 days, so that there is no perpetual day-side or night-side.
Every part of the planet gets both day and night, and the Sun moves in a rather complicated path in Mercury's sky, growing larger and smaller, and backtracking on some occasions. If I were writing this book today, I would take all this into account, I hope my Gentle Readers enjoy this book anyway, as an adventure story, but please don't forget that the advance of science can outdate even the most conscientious science-fiction writer and that my astronomical descriptions are no longer accurate in all respects.
Isaac Asimov
1. The Ghosts of the Sun
Lucky thought: At least things are breaking fast.
He had been on Mercury only an hour. He had had scarcely time to do more than see his ship, the Shooting Starr, safely stowed in the underground hangar. He had met only the technicians who had handled the landing red tape and seen to his ship.
Those technicians, that is, and Scott Mindes, engineer in charge of Project Light. It had been almost as though the young man had been lying in wait. Almost at once he had suggested a trip to the surface.
To see some of the sights, he had explained.
Lucky did not believe that, of course. The engineer's small-chinned face had been haunted with trouble, and his mouth twitched as he spoke. His eyes slid away from L'ucky's cool, level glance.
Yet Lucky agreed to visit the surface. As yet, all he knew of the troubles on Mercury was that they posed a ticklish problem for the Council of Science. He was willing to go along with Mindes and see where that led him.
As for Bigman Jones, he was always glad to follow Lucky anywhere and any time, for any reason and no reason.
But it was Bigman whose eyebrows lifted as all three were getting into their suits. He nodded almost unno-ticeably toward the holster attachment on Mindes's suit.
Lucky nodded calmly in return. He, too, had noticed that protruding from the holster was the butt of a heavy-caliber blaster.
The young engineer stepped out onto the surface of the planet first. Lucky Starr followed and Bigraan came last.
For the moment, they lost contact with one another in the nearly total darkness. Only the stars were visible, bright and hard in the cold airlessness.
Bigman recovered first. The gravity here on Mercury was almost exactly equal to that on his native Mars. The Martian nights were almost as dark. The stars in its night sky were almost as brilliant.
His treble voice sounded brightly in the receivers of the others. "Hey, I'm beginning to make things out."
So was Lucky, and the fact puzzled him. Surely starlight could not be that bright. There was a faint, luminous haze that lay over the fumbled landscape and touched its sharp crags with a pale milkiness.
Lucky had seen something of the sort on the Moon during its two-week-long night. There, also, was the completely barren landscape, rough and broken. Never, in millions of years, either there on the Moon or here on Mercury, had there been the softening touch of wind or rain. The bare rock, colder than imagination could picture, lay without a touch of frost in a waterless world.
And in the Moon's night, too, there had been this milkiness. But there, over half the M'oon at least, there had been Earth-light. When Earth was full it shone with sixteen times the brightness of the full Moon as seen from Earth.
Here on Mercury, at the Solar Observatory at the North Pole, there was no near-by planet to account for the light.
"Is that starlight?" he finally asked, knowing it wasn't.
Scott Mindes said wearily, "That's the coronal glimmer."
"Great Galaxy," said Lucky with a light laugh. "The corona! Of course! I should have known!"
''Known what?" cried Bigman. "What's going on? Hey, Mindes, come on, give!"
Mindes said, "Turn around. You've got your back to it."
They all turned. Lucky whistled softly between his teeth; Bigman yelped with surprise. Mindes said nothing.
A section of the horizon was etched sharply against a pearly region of the sky. Every pointed irregularity of that part of the horizon was in keen focus. Above it, the sty was in a soft glow (fading with height) a third of the way to the zenith. The glow consisted of bright, curving streamers of pale light.
"That's the corona, Mr. Jones," said Mindes.
Even in his astonishment Bigman was not forgetful of his own conception of the proprieties. He growled, "Call me Bigman." Then he said, "You mean the corona around the Sun? I didn't think it was that big."
"It's a million miles deep or more," said Mindes, "and we're on Mercury, the planet closest to the Sun. We're only thirty million miles from the Sun right now. You're from Mars, aren't you?"
"Born and bred," said Bigman.
"Well, if you could see the Sun right now, you'd find it was thirty-six times as big as it is when seen from Mars, and so's the corona. And thirty-six times as bright too."
Lucky nodded. Sun and corona would be nine times as large as seen from Earth. And the corona could not be seen at all on Earth, except during periods of total eclipse.
Well, Mindes had not altogether lied. There were sights to be seen on Mercury. He tried to fill out the corona, to imagine the Sun it surrounded which was now hidden just below the horizon. It would be a majestic sight!