The Secret of the Ninth Planet Part 15

Boulton showed no further effects from his experience. In time, the _Magellan_ drew near Jupiter. Callisto, its fifth satellite outward, moved about the mighty planet at a distance of 1,170,000 miles. It was a large satellite as they go, 3,220 miles in diameter, larger, in fact, than Mercury. But, as Russ explained, it was a queer place in its own fas.h.i.+on.

For despite its size, Callisto was apparently not a solid body as we think of it. Its density totaled only a little more than that of water, its ma.s.s half that of the Earth's Moon--a notoriously porous body.

They bore down on Callisto, matching their speed to its, and swung close to its surface. It had almost no atmosphere, just a thin layer of the heavier gases. It was a belted world, without clearly defined continents or surface markings. Its equatorial zone was one vast, featureless belt of darkish-gray. Its temperate zones were white, with patches of yellow here and there. But its poles were gray again.

"The satellite's like a huge ball of thin mud that's never hardened,"

said Burl as they studied the strange terrain.

"The equator's the softest--it seems to be a river of muddy water, hundreds of miles wide--only it can't be water. Probably semisolidified gases holding dust and grains of matter in suspension," said Russ. "The temperate zones are the same stuff, only colder, and therefore more stable. A thin crust of frozen gases over a planet-wide ocean of semiliquid substance."

"The Sun-tap station's on the southern pole," said Burl. "That must be solid."

It was. The poles of Callisto were actually two continent-sized islands of sh.e.l.l. Dry, mudlike stuff, hard as rock, floating on the endless seas of the semiliquid planet.

The station, a ringed setup quite like the one on Earth, stood in the geographic center of the south pole. The _Magellan_ hovered over it while a landing party went down in the four-man rocket plane.

Clyde, Haines and Burl were the landing party. This time, only Burl entered the station after a hole had been blasted in the outer sh.e.l.l.

While the redheaded astronomer took samples and made observations, Haines kept watch. n.o.body knew what type of defense awaited them here.

Burl found the controls easily enough. He was afraid that he might have lost his physical charge, but it was not so. The controls functioned, the Sun-tap station died. The effect was not very noticeable, for Callisto was already far from the Sun and the thin atmosphere could not diminish the dark sky of outer s.p.a.ce. What the great masts caught must have been only the relay from other stations--or perhaps the invisible rays of the distant Sun.

Burl saw no reason to linger, and the three of them gathered up their equipment. As they started back toward the rocket plane, they heard an ominous rumble in the ground.

A sudden spurt of blazing gas shot up from the center of the station.

"Duck!" yelled Haines, and they fell flat on the ground. Burl held his hands protectively over his head, as an explosion shook the building.

There was no rain of rocks. Whatever the blast, Callisto's gravity was too weak to attract the debris that flew high above the station.

"It was an atomic explosion!" Haines shouted into his helmet mike. "They mined the station. Run for it!"

They raced for the rocket plane. As they ran, Burl felt the ground quiver beneath him, and huge cracks began to spread, rippling through the hard ground.

They reached the plane and piled in. Russ took off just as the surface cracked open in a thousand places like an ice sheet breaking in an Arctic thaw.

As they rocketed back to the _Magellan_, the whole polar cap, an area hundreds of miles around the Sun-tap station, split apart. Great spurts of liquid magma, the liquid gas-dust from the heart of the planet, shot up like fountains. Parts of the sh.e.l.l-like polar continent were disappearing beneath this new ocean.

"Their little atomic bomb shattered the thin crust. The whole polar island will probably sink," said Russ. "It was a clever trap. They knew what would happen."

"Saturn next," said Burl. "What'll they have set up there?"

They reached the _Magellan_, loaded the rocket plane aboard, and pulled out, setting their course for the ringed planet. But even as they did so, something was coming from Saturn to meet them.

Chapter 14. _Rockets Away!_

The next lap of their journey was uneventful. Saturn, the next outward planet from the Sun, and the second largest, would present the same problem as Jupiter. This world, famous for its mysterious rings, was about 71,000 miles in diameter and had a large family of satellites--nine in all. The Sun-tap station would be on one of these, Burl thought.

Saturn was also almost as far out from Jupiter as Jupiter itself had been from the Sun. This meant that the trip would be as long for the _Magellan_ as the distance they had already traveled to get to Jupiter.

Fortunately the A-G drive was a remarkable thing--it was possible to accelerate to fantastic speeds--in theory, probably right up to the speed of light. And so, where great distances were concerned, the s.h.i.+p simply rushed its fall through on Saturn's line of gravitation.

Boulton had fully recovered and showed no lingering signs of the strange electronic charge. Because of the limited size of the crew, Lockhart put the Marine captain back on full duty--he would partic.i.p.ate in future landings as if nothing had ever happened.

At the same time, Lockhart cautioned Haines, Burl and Ferrati to keep their eyes on him. It was always possible that the foe's weapon had made some more lasting mark.

Haines had his group make a new inventory of their weapons. Burl, working with them in a s.p.a.ce suit, in the partially protected region of the cargo hull, was surprised at the variety. There was a second rocket plane, a two-man outfit. In addition, they had a large store of offensive weapons, including a small but formidable supply of atomic explosives.

Haines gave Burl and Ferrati--who were new to military weapons--brief introductory lectures on their use. Burl saw just what a hand-sized, tactical atomic sh.e.l.l looked like and how it worked. He learned how to operate the heavy-caliber rocket gun which hurled this tiniest of atomic bombs.

And so the time pa.s.sed, and the amazing disc of Saturn began to grow in their viewplates. It was banded, much like Jupiter, and its brilliant rings surrounded it with a mystic halo that set it apart from all the other worlds of the Sun's family.

Burl was watching Saturn through the largest of the nose viewplates when he thought that he saw a black dot crossing its face. He had located the known moons of Saturn and this was not one of them. Excited, he called Russell Clyde. "Could it be a tenth satellite?" he asked, pointing out the tiny dot.

Russ squinted his eyes; then, calculating mentally, he shook his head, "I don't think so. It looks to me more like something that's in s.p.a.ce between us and Saturn. In fact--it must be fairly close to us for us to see it at all." He turned to Lockhart who was at the control panel with Oberfield.

"You'd better have a look. Could be a giant meteor coming in our direction."

"We're moving mighty fast," commented Oberfield. "It should have pa.s.sed us already if it were a meteor. Instead, it seems to be maintaining the same distance--neither growing larger nor smaller. Acts very odd for a natural body."

"Uh, uh," said Lockhart. "This calls for caution." He quickly went back to the controls, pressed the general alarm b.u.t.ton, then called into the intercom. "All hands to emergency stations. Haines and party, please prepare defensive positions."

"This means me," gulped Burl, and scooted down the central hatch, almost colliding with Caton and Shea on their way to the engine room. He met Haines, and, with neat dispatch, all four slipped into s.p.a.ce suits. Then out through the cargo hold to posts by escape hatches.

Burl and Haines, at the main entry port, unlimbered the long rocket launcher that had been set up in the pa.s.sageway. Haines placed three sh.e.l.ls of differing strength in position.

They heard through their helmet phones that the mysterious dot was drawing closer. Haines set up one of the launching racks, which was equipped with a telescopic sighter, and peered through the eyepiece.

Apparently he caught it, for he grunted, then motioned to Burl to take a look.

It was no natural object. It was the shape of a dumbbell--two spheres joined together by a short middle bar. One sphere was a deep, golden color, the other a bluish-silver, the connecting rod a coppery metal.

"The pattern of spheres certainly suggests the Sun-tappers to me," said Burl. Haines murmured his agreement.

Lockhart's voice came on the phones. "We've decided it's one of the Sun-tapper s.h.i.+ps. We're not going to wait to make sure. Before we left Earth, I can now inform you, I received a directive from the President to regard the builders of these Sun-tap stations as active enemies. My orders are that we are not to attempt to undertake peaceful contact, but are to treat them on sight as armed foes in the field. To do otherwise is to risk Earth's last active defense--this s.h.i.+p.

"I think I don't have to argue this further, considering our recent experiences." His voice hesitated, then rang out firmly, "Haines, you can commence firing at will!"

Haines clicked his tongue and reached for one of the sh.e.l.ls. "Okay, Burl, aim at her direct. This one's got a proximity nose that'll beam at her and drive itself where ever she ducks."

He slid the rocket sh.e.l.l into the launcher, Burl sighted, and then Haines pressed the trigger. There was a whoosh of fire and a flare from the launcher's nose. A minute spark winged into the darkness toward the spot, still many miles away, where the strange s.h.i.+p hung.

They watched with bated breath. Suddenly there was a flash of light from the other s.h.i.+p--a vivid lightning bolt which leaped out and flared up briefly in s.p.a.ce. Then darkness again.

"They fired a burst of energy at us. It hit the rocket sh.e.l.l instead,"

said Haines. "Well, now we know. They use bolts of pure energy--something like the one they fired at Boulton."

He fitted another sh.e.l.l into the launcher, and fired again. Again a spark winged its way, and the bolt of energy burst out to detonate the sh.e.l.l. Burl whistled. "How did they spot it so fast?" he asked.