Upon this eventful night the conning-tower had been raised, and the two chums had been amusing themselves by peering through powerful telescopes at the heavenly bodies around them. It was truly a wonderful, a fascinating sight, and one which Gerald, especially, was never tired of contemplating. The various constellations blazed out with a vividness and beauty far exceeding their appearance as seen through our atmosphere from the surface of the Earth. Thanks to Malanda, the two lads had learned to distinguish the planets from the far-more distant fixed stars. They knew that the latter were at such tremendous distances that they ’didn’t count,’ as Jack put it; the only ones they were likely to have anything to do with being the planets, which, like our Earth, are always revolving round our sun. Of course, as they were going to visit Mars, they watched that orb particularly; and they felt a special interest in noting how its pinkish-red light increased in size and intensity as they drew nearer. Next in interest came our Earth, which they had so recently left, whose bluish light waned exactly in proportion as that of Mars waxed stronger. Then there was beautiful Saturn, with its wondrous rings of light; perhaps they were also to visit that mysterious orb, and learn what those lustrous bands were composed of! Besides these, there were plenty of curious things to watch and admire. The planets had their moons in attendance upon them—some having two, some as many as eight—all behaving as our own moon does—each, that is to say, showing in turn as a thin crescent, a half-moon, a full-moon, and so on; and the voyagers had watched these changes with interest which never flagged. It seemed such a strange thing to think of: several moons round one planet; one, perhaps, a new moon; and two or three others near the full, all shining at the same time! Now, it was while they were gazing at these beautiful sights that Jack noticed a tiny speck of light which struck him as unfamiliar. He mentioned it in an undertone to Gerald, who, just then, was half-watching what was to be seen of Saturn, half-dreaming of what lay beyond. Gerald pointed his telescope in the direction indicated, and looked at the speck of light, but seeing nothing particular in its appearance, turned his attention again to other objects. Jack, however, was more observant. His acute, practical sense had told him that here was something different from anything he had seen before. He promptly recognised two or three very important points in connection with it. One was that its light was different in colour from that of anything else he could see. Another was that it was very unsteady, yet it did not ’twinkle’ as do the far-distant stars; and yet another was that it was growing in intensity very quickly.