Not ten miles off they beheld Mars's inner moon, and though their own speed caused them to overtake and rush by it like a whirlwind, the satellite's rapid motion in its orbit, in a course temporarily almost parallel with theirs, served to give them a chance the better to examine it. Here the mountain ranges were considerably more conspicuous than on Deimos, and there were boulders and loose stones upon their slopes, which looked as if there might at some time have been frost and water on its surface; but it was all dry now, neither was there any air. The evidences of volcanic action were also plainly visible, while a noticeable flattening at the poles showed that the little body had once rotated rapidly on its axis, though whether it did so still they had not time to ascertain. When abreast of it they were less than two miles distant, and they secured several instantaneous impressions, which they put aside to develop later. As the radius of Phobos's circle was far shorter than that of the parabolic curve they were making, it began to draw away, and was rapidly left behind. Applying the full apergetic force to Mars and the larger moon, they shot away like an arrow, having had their speed increased by the planet's attraction while approaching it, and subsequently by repulsion.
"Either of those," said Bearwarden, looking back at the little satellites, "would be a nice yacht for a man to explore space on. He would also, of course, need a sun to warm him, if he wished to go beyond this system, but that would not have to be a large affair--in fact, it might be smaller than the planet, and could revolve about it like a moon."
"Though a sun of that size," replied Cortlandt, "might retain its heat for the time you wished to use it, the planet part would be nothing like as comfortable as what we have here, for it would be very difficult to get enough air-pressure to breathe on so small a body, since, with its slight gravitation-pull, to secure fifteen pounds to the square inch, or anything like it, the atmosphere would have to extend thousands of miles into space, so that on a cloudy day you would be in darkness. It would be better, therefore, to have such a sun as you describe and accompany it in a yacht or private car like this, well stocked with oxygen and provisions. When passing through meteoric swarms or masses of solid matter, collision with which is the most serious risk we run, the car could follow behind its sun instead of revolving around it, and be kept from falling into it by partially reversing the attraction. As the gravitation of so small a sun would be slight, counteracting it for even a considerable time would take but little from the batteries."
"There are known to be several unclaimed masses," added Ayrault, "with diameters of a few hundred yards, revolving about the earth inside the orbit of the moon. If in some way two of these could be brought into sufficiently violent collision, they would become luminous and answer very well; the increase in bulk as a result of the consolidation, and the subsequent heat, about serving to bring them to the required size. Whenever this sun showed spots and indications of cooling, it could be made to collide with the solid head of some comet, or small asteroid, till its temperature was again right; while if, as a result of these accretions, it became unwieldy, it could be caused to rotate with sufficient rapidity on its axis to split, and we should have two suns instead of one."
"Bravo!" said Bearwarden. "There is no limit to what can be done. The idea of our present trip would have seemed more chimerical to people a hundred years ago than this new scheme appears now."
Thus they sat and talked, or studied maps and star-charts, or the stars themselves, while the hours quickly passed and they shot through space. They had now a straight stretch of over three hundred million miles, and had to cross the orbits of innumerable asteroids on the way. The apparent size of the sun had by this time considerably decreased, and the interior of the Callisto was no longer uncomfortably warm. They divided the day into twenty-four hours from force of habit, and drew the shades tightly during what they considered night, while Bearwarden distinguished himself as a cook.
Chapter III.[Contents]
HEAVENLY BODIES.
The following day, while in their observatory, they saw something not many miles ahead. They watched it for hours, and in fact all day, but notwithstanding their tremendous speed they came but little nearer.