By eight o'clock next morning they would find Jupiter "new" again.
They were now falling very rapidly towards the huge planet, and, since there is no up or down in Space, the nearer they got to it the more it appeared to sink below them and become, as it were, the floor of the Celestial Sphere.

As the crescent approached the full they were able to examine the mysterious bands as human observers had never examined them before.

For hours they sat almost silent at their telescopes, trying to probe the mystery which has baffled human science since the days of Galileo, and gradually it became plain that Redgrave was correct in the hypothesis which he had derived from Flammarion and one or two others of the more advanced astronomers.
"I believe I was right, or, in other words, those that I got the idea from are," he said, as they approached the orbit of Calisto, which revolves at a distance of about eleven hundred thousand miles from the surface of Jupiter.
"Those belts are made of clouds or vapour in some stage or other.

The highest--the ones along the Equator and what we should call the Temperate Zones--are the highest, and therefore coolest and whitest.

The dark ones are the lowest and hottest.