Martt flushed a trifle. "It wasn't my fault--at least I didn't think so. At a velocity like that the space there between the orbits of Mars and Jupiter is horribly crowded. Brett was asleep. I sat by the instrument table staring down into the floor window at the black firmament into which we were dropping. You people take a voyage like this as a matter of course--but it was my first time off earth, and the beauty of it--of the heavens--well, I tell you it impressed me. The black firmament--those blazing constellations beneath us--the full moon of Jupiter every moment growing larger like a white round lamp down there. "Well, anyway, perhaps, I was lost in thoughts of it--when leaping up out of the blackness came a great round silver disk. A hundred times the size of our full moon. Then a thousand. It was below me, but off to one side. It swept past, so close I could see its barren, rocky surface--a range of desolate gray mountains; and I could see, too, its rotation, like a ball tossed into the air slowly rotating. Before I could think to do anything--even to make a move--the asteroid went past, out of my field as I looked through the floor window. For a moment I saw it rising past a side window and then it was above us--gone completely beyond my sight in a moment or two. I want to tell you I was frightened--I called Brett down at once." Brett laughed. "I found him white, shaking like a tower-trembler. If a collision had really threatened, he could have thrown the main Time-switch. Thrown us suddenly into the asteroid's past or future--I had told him that--but when the danger came, he never thought of it." "I never did," Martt confessed. "How close did the asteroid pass?" I asked. "I saw one once, on a Martian trip----" "I suppose we passed it at a distance of some three thousand miles," Brett answered. "But at three million miles an hour we were traveling that distance in three or four seconds. It was a narrow escape. The asteroid's attraction had drawn us aside from our course--but I soon rectified that." "I meant to explain about attraction a moment ago, Frank," Dr. Gryce interrupted. "The attraction of the vehicle on our planets is why Brett could not yet increase his size. Jupiter and Saturn were pulling the vehicle onward, and in direct proportion to the mass, of course, the vehicle was pulling at them. An infinitesimal pull--but had Brett increased its size materially--while still close to our planets--the vehicle would have been a seriously disturbing element. I did not want that. Indeed, with any great size-increase, the vehicle moving out there would have thrown our whole system into chaos."