The remainder of that day they kept on shooting forward toward Mars, nothing occurring to mark the passage of time, save the monotonous ticking of various clocks. There was nothing to be seen, save the glare of sunlight outside. "Aren't we ever going to meet with world, or a wandering star, or something?" asked Jack rather discontentedly. "There's no telling when we may pass near one," said Mr. Roumann. "S'posin' we hit one?" asked Washington, his eyes becoming large with fear. "There's not much danger. My instruments will warn me when we approach any of the heavenly bodies, and we can steer clear of them. The only things we have to fear will be comets, and their orbits are so irregular that there is no telling when we may get in the path of one." "What will happen when we do?" asked Mark. Mr. Roumann shrugged his shoulders. "We'll do our best to get out of the way," he said. "And if we can't?" "Well--I guess that will be the end of us." This was a new danger, and one the boys had not thought of before. But the German scientist did not seem to attach much importance to the matter. They traveled on for two days, nothing of moment occurring. The Annihilator, true to its name, fairly ate up space, though they were still far from Mars. It was on the morning of the third day. The two boys and Professor Henderson were in the pilot house, and Mr. Roumann was in the engine-room, adjusting the Etherium motor, for he expected to shortly put it in operation. Suddenly Jack, who was looking at one of the instruments on the front wall, uttered a cry. "What's the matter?" asked Mark. "We're approaching something!" was the answer. "Some sort of heavenly body. Look at that indicator!" The hand or pointer on a peculiar dial was moving violently to and fro. "Call Mr. Roumann," suggested the professor. "I don't know just what to do." Mr. Roumann hurried into the pilot house, gave a quick glance at the indicator, and exclaimed: "We are nearing a planetoid, or, as some call them, an asteroid!" "Is there any danger?" asked Mark. "No. Fortunately the instrument gave us timely warning. I shall simply steer to avoid it. It is a small, unnamed planet flying around in space. There are many of them." "Can we go close enough to it to see it?" asked Jack, who was a curious lad. "I think so. I'll try it, anyhow." Mr. Roumann made some adjustments to the levers and wheels controlling the motor, and, by turning on a little more power on one side of the projectile, caused it to swerve to one side. A few minutes later he called out: "Look from the window!" The boys gazed out. They saw that they were rushing past a dark mass, that looked as if it was composed of heaped up, black rocks, piled in fantastic masses, with great chasms here, and towering peaks there. It seemed to be several miles in diameter, and looked like a great ball. "A small, dead world," remarked Mr. Henderson. "I suppose our planet will be like that some time."