In the 340,000,000 mile belt of space between the orbits of Mars and Jupiter revolve some thousands of miniature worlds ranging from golf-ball size to nearly 500 miles in diameter.
by Walter Gillings
How they came to be there is one of the major mysteries of astronomy.
One view is that they are the debris of a huge comet, which once passed through the Solar System, was captured by giant Jupiter and forced to revolve around the Sun until all that remained of its former glory was the bits and pieces we call the Asteroids. A second theory is that they are the remnants of the material which went to make the Solar System, thrown off by the Sun and prevented by Jupiter’s gravitational influence from coalescing in a mass which might have become another planet of respectable dimensions.
A third, more fascinating notion is that they were once a planet which broke into pieces ages ago in a tremendous explosion or a I series of them, caused by excessive radio activity in its core. A world that blew itself up.
Since Ceres, the largest of these midget worlds, was spotted by the Italian astronomer Piazzi in 1801, some 1,200 of them have been observed, but it is estimated that as many as 50,000 actually exisit. The telescopic camera has multiplied by four the number of previous discoveries, and recent improvements in the method of photographic detection promise not only to increase the count but to confirm the latest theory that the bigger planetoids may have satellites.
It is feasible that those of greater mass might attract the smaller bodies into regular orbits around – them, making them tiny moons, just as Jupiter is believed to have drawn several of the larger ones into his clutches. And even Mars is not above suspicion of having acquired his two diminutive satellites, Phobos and Deimos, in that way.
The orbits of some Asteroids are so eccentric that they intersect the Earth’s and occasionally bring them very close to us. Little one-mile diameter Hermes broke all records a few years back when he ventured within 485,000 miles of our perturbed planet. But Luna need fear no rival and the anxious can sleep soundly in their beds. For Earth is hardly massive enough to capture any of those bold but speedy spirits, and the possibility of collision is remote.
Up to now, these so-called “vermin of the sky” have been of use only to astronomers in checking up on their measurements and keeping them ever on the alert. The search for more minor planets is with them an absorbing pastime, revealing some 200 new discoveries every year; though with all their vigilance there are some that get lost. The American discoverer of twenty-nine planetoids went so far as to leave his surviving colleagues a bequest in his will with the proviso that they should keep a constant eye on his elusive finds.
But in time to come, if we are to believe the hopeful advocates of space-flight, men may
actually set foot on those pocket-size planets, using them as stepping stones in his travels through the interplanetary gulfs; or may even control their erratic paths, shift them entirely out of their orbits and transfer them to regions where they will be most useful as “space stations,” millions of miles away from, their present crowded situation. He may find in them, too, easily accessible mineral resources to aid him in his spatial projects. And perhaps traces of the civilization which existed, eons ago, on the planet of which they are the scattered fragments.
For the lost planet hypothesis of the Asteroids’ origin, first advanced in the early days of their discovery, only to be discarded when a systematic comparison of their muddled orbits failed to produce any evidence to support it, is now coming back into favor as the most likely explanation of their tantalizing mysteries. The more we learn, the more plausible the”most “fantastic” theory becomes. For instance, there’s the matter of Vesta’s peculiar brilliance.
This third biggest of-the Asteroids, 240 miles across, shines with a light more intense than that of our own Moon or even of the planet Venus with her dense, cloudy atmosphere. This high albedo is one of the puzzles astronomers can’t account for, while denying the possibility of any of these wee worlds having mass enough to retain an atmosphere or even a coating of ice.
The only possible solution is that Vesta consists of quartz crystals or white rock with great reflective power. And since it is most unlikely that a mass comprising such a limited number of elements should have been thrown off by the Sun in the first place, the fact of Vesta’s brilliance is considered to enhance the idea of the exploded planet of the long gone past. If such a world existed, its size would have been rather less than that of Earth, and in view of its distance from the Sun it would have cooled and become habitable long before this planet. If the examination of meteors originating in the Asteroid Belt is any indication, its disruption must have occurred
comparatively recently, astronomically speaking. Before that, it may have harbored life-intelligent life, which has- left its mark somewhere among those bits and pieces of the world that was. When we salvage those remains, we’ll find out, perhaps.