"Very unlikely. Besides, I am having the cube refitted for a two-months' cruise. Rather thought I'd like to visit Mars and Jupiter in person.
"But when it comes to leaving the solar system entirely the telepathic method is the only one that will work; even the nearest of the fixed stars is out of the question."
"How far is that?" Smith inquired.
"The nearest? About four and a half light-years."
"Yes, but what's a light-year?"
"It amounts to sixty-three thousand times the distance from here to the sun!"
Smith whistled. "Nothing doing in the cube, that's sure. Besides, could we expect to find any people like us in the neighborhood of that star?"
"Not Alpha Centauri." The doctor reached for one of the Venusian books, and pointed out certain pages. "It seems that the Class IIa stars—that is, suns—are the only ones which have planets in the right condition for the development of humans. The astronomers already suspected as much, by the way. But the Venusians have definitely named a few systems whose evolution has reached points almost identical with that of the earth.
"Now, until we have acquired a certain amount of ability" —examining the books more closely—"our best chance will lie in the neighborhood of a giant star known to us as Capella."
"Capella." Billie had drawn a star-chart to her side. "Where is that located?"