A sandwich in one hand, I wandered over the vessel. It was reassuringly solid and concrete. And yet there was something lacking.
"Garth," I asked, "what's become of the sun?"
"I thought you'd want to know that." He led me to the rear telescope.
"But I don't see anything."
"You haven't caught on yet. See that bright yellowish star on the edge of the constellation Scorpio. That's it."
Involuntarily, I gasped. "Then—how far away are we?"
"I put on full acceleration fifteen hours ago, when we passed Neptune, and we have covered thirty billion miles—three hundred times as far as from the moon to the sun, but only one half of one per cent of a light-year."
I was speechless, and Garth led me back to the control board. He pointed out the acceleration control, now turned up to its last notch forward; he also showed me the dials which were used to change our direction.
"Just keep that star on the cross hairs. It's Pi Orionis, a little out of our course, but a good target since it is only twenty-five light-years away. Half the light is deflected on this screen, with a delicate photo-electric cell at its center. The instant the light of the star slips off it, a relay is started which lights a red lamp here, and in a minute sounds a warning bell. That indicator over there shows our approach to any body. It works by the interaction of the object's gravitational field with that of my projector, and we can spot anything sizable an hour away. Sure you've got everything?"