The car was rising, at first slowly, but ever faster and faster, from the roof, not as a helicopter rises, not as a dirigible rises, but more as a heavy body falls, with high acceleration ever faster and faster. Soon it was rising quite rapidly, straight up. Then another tiny red bulb flashed into life on Waterson's switchboard, and the ship suddenly tilted at an angle of thirty degrees. Then it shot forward, and continually accelerated an already great speed, till New York lay far behind, and then the sky became dark and black, and now the stars were looking in at them, not the winking, blue stars of Earth, but the blazing, steady stars of infinite space, and they were of every color, dull reds, greenish, and blue. And now as they shot on across the face of Earth far below, Gale watched in rapture the magnificent view before him, seeking the old friends of Earth—Mars, Venus, Jupiter, and the other familiar, gleaming points. Then he turned his gaze toward the Sun, and cried out in astonishment, for the giant sphere was a hard, electric blue, like some monster electric arc, and for millions of miles there swept from it a great hazy, glowing cloud, the zodiacal light, almost invisible from Earth, but here blazing out in indescribable beauty.
"We're in space! But, Steve, look at the sun! What makes it look blue? The glass of the window isn't blue, is it?" said Gale excitedly.
"We're in space all right—but it isn't glass you're looking through; it is fused quartz. Glass that thick would crack in a moment under the stress of temperature change it has to undergo. The sun looks blue because, for the first time in your life, you are seeing it without having more than half its light screened off. The atmosphere won't pass blue light completely and it cuts off the ultra-violet transmission very shortly after we leave the visible region of the spectrum. The reason the sun has always looked yellow is that you could never see that blue portion of its spectrum. Remember, a thing gets bluer and bluer as it gets hotter. First we have red hot, bright red, yellow, white, then the electric arc is so hot that it gives blue light. But the sun is nearly two thousand degrees centigrade hotter than the electric arc. Naturally it is blue. Also, I'll bet you haven't found Mars, have you?"
"No, Steve, I haven't. Where is it?"
"Right over there. See it?"
"But that can't be Mars. It's green, green as the Earth."
"But it is Mars. The reason Mars looks red from Earth is that the light that reaches us from Mars has had to go through both its own atmosphere and through ours, and by the time it reaches us, it is reddened, just as a distant plane beacon is. You know how a light in the distance looks red. That is what makes Mars look red."
"Mars is green. Then it is possible that the life on Mars may be the same as that of Earth!"
"Right, Dave. It probably is. Remember that the chlorophyll that gives the planets their color is also the material that can convert sunlight energy into fixed energy of starches and sugars for the plant, and probably the same material is serving in that capacity all over the universe, for carbon is the only element of the more than a hundred that there are that can possibly permit life's infinitely complicated processes to progress."
"But I thought there were only ninety-two elements."