The explosion created a cloud over an area about seven hundred miles in diameter and forty miles high. It was dull gray with a yellowish tinge and a different color from the atmospheric phenomena customarily seen near Mars. Saeki believes the blast might have destroyed any form of life existing on the planet, but even though the telescopic camera recorded a violent explosion, other authorities do not believe the planet was wrecked. The canals first discovered on Mars by Giovanni Schiaparelli, about 1877, are still apparent on photographs. Mars is now being carefully watched by astronomers. If there are more of the strange explosions, the planet will be scanned constantly for some clue to their nature. If a mysterious explosion on Mars, or any other planet, were found of atomic origin, it would cause serious concern on earth. Suppose for a moment that it happened many years from now, when we will have succeeded in space explorations. At this time, let us assume our explorers have found that Mars is experimenting with high-altitude rockets; some of them have been seen, rising at tremendous speed, in the upper atmosphere of Mars. Then comes this violent explosion. A scientific analysis of the cloud by astrophysicists here on earth proves it was of atomic origin. The first reaction would undoubtedly be an immediate resurvey of Mars. As quickly as possible, we would establish an orbiting space base—out of range of Martian rockets—and try to find how far they had advanced with atomic bombs. Samples of the Martian atmosphere would be collected and analyzed for telltale radiation. Observer units would be flown over the planet, with instruments to locate atom-bomb plants and possibly uranium deposits. The rocket-launching bases would also come under close observation. We would try to learn how close the scientists were to escaping the pull of gravity. Since Mars’s gravity is much less than the earth’s, the Martians would not have so far to progress before succeeding in space travel. The detailed survey by our space-base observers would probably show that there was no immediate danger to the earth. It might take one hundred years—perhaps five hundred—before the Martians could be a problem. Eventually, the time would come when Mars would send out space-ship explorers. They would undoubtedly discover that the earth was populated with a technically advanced civilization. Any warlike ideas they had in mind could be quickly ended by a show of our superior space craft and our own atomic weapons—probably far superior to any on Mars. It might even be possible that by then we would have finally outlawed war; if so, a promise to share the peaceful benefits of our technical knowledge might be enough to bring Martian leaders into line. Regardless of our final decision, we would certainly keep a lose watch on Mars—or any other planet that seemed a possible threat.