II
They adjusted helmets and manipulated the manual locks of the double doors, with some experiment. John finally convinced himself that he could re-enter without difficulty. Then the two Earth people stepped out into a weird atmosphere under a strangely small sun. The sky was dark blue, tending toward black. Stars glittered, though it was still day. Their helmets provided a mixture of oxygen with the planet's natural atmosphere.
"It's like a dream, John."
The hills were old and worn out but there were no trees. Deep shadows folded into the distance in the cold slanting sunlight, tracing sandy curves with velvet-like smoothness.
John answered her thought, "Those vivid colors and deceptive distances remind me of my boyhood in Idaho. I'll bet there's the same difference between light and shade, too. Let's step into the shadow of that rock and see if it isn't suddenly much cooler."
He led her to a pyramid-like rock projecting about twenty feet out of the sand, and casting a shadow toward them.
Hilda exclaimed, "Yes, it is colder. Why?"
"The thin air always diffuses heat less than moist heavy air near the sea, and at a lower altitude. I'll bet on a cold day you could get frozen out of the sunlight before you realized."
"And there are no clouds. What a strange dark sky!"