As I watched carefully, the satellite finally came into view, but very much more distant from Mars than before. Also, it moved very slowly now, and seemed to grow larger as it approached the disc. I pointed it out to the doctor, and remarked that it was acting quite differently. Just as it entered upon the orb of Mars, another moon, somewhat smaller, mounted hurriedly from the under side of the planet and began hastily ploughing her way over the ruddy disc.
"That last one is the one I saw before, that is my Phobos!" I cried excitedly.
"Then the other slow one is Deimos, the outer moon. She appears the larger to us now, because her greater distance from Mars makes her nearer to us, but she appears to the Martians as the smaller. We must observe closely, and we may discover some new and lesser satellites which Earthly telescopes have never found."
"Time enough for that when we land on Mars," I answered. "If we get in past these two without being hit, I shall be satisfied. You dare not venture in front of that Phobos, and I don't see how you can ever overtake her if you approach from behind."
"That reminds me to slacken speed, for we must be getting very near," he said. "Please weigh yourself every few minutes and note your increasing weight. You should weigh seventy-two pounds on Mars, and eight pounds at the distance of Phobos."
He immediately reversed currents, and when I reported that I weighed almost a pound, it frightened him, and he turned in the full power of the negative currents to overcome our momentum. And it proved that the repelling power of Mars at the distance of 15,000 miles, which this indicated, was not at all strong against the great velocity we had been daily acquiring. I hung upon the scales every few minutes, and reported a steadily increasing weight up to three pounds.
"That shows a distance of eight thousand miles," he figured. "Almost exactly in the orbit of Deimos, but she has safely passed, and will not return for thirty hours. We must turn the rudder hard over to the right, and sail around the planet in a circle until Phobos overtakes us; then, if we approach her travelling in the same direction at almost the same rate of speed, her gravitational attraction will pick us up and draw us safely ashore."
Mars was already an enormous orb ahead of us, and many of his features, such as oceans, ice-caps, and continents, could easily be distinguished; but we paid little attention to them, being occupied with making a safe landing on Phobos, and expecting to make a systematic study of him from there.
"We must not attempt a landing on the outer side of the satellite," the doctor reflected, "for we should have no way of getting around to the inner side to make our observations. We must go within her orbit, and then as she comes past allow her attraction to draw us gently toward her."
We had quickly overtaken and passed Deimos, far within her orbit. I was keeping a close watch for Phobos out of the rear window as we circled about Mars at a distance which we calculated, from my weight on the scales, must be within the path of the satellite. We were circling in the same direction that the great planet was rotating, and yet we passed by things on his surface, which proved that we were travelling faster than his rotation. The doctor noticed, with his telescope, a brilliant snow-capped peak of a great mountain towering up from a small island. The contrast of the snow peak, with the darkish green waters all around it, was the most pronounced thing visible on the great planet, and he decided this must be the white spot detached from the polar ice which our astronomers have frequently observed at about twenty-five degrees south latitude, and to which they have given the name Hall's Island.