Note 9 — Chapter X

Besides the curious relation of the times of rotation of the planets, just noticed, there is another curious relation, of their distance from the Sun, which any one, wishing to frame an hypothesis on the origin of our Solar System, ought by all means to try to account for.

The distances from the Sun, of the planets, Mercury, Venus, Earth, Mars, the Planetoids, Jupiter, Saturn, Uranus, are nearly as the numbers,

4, 7, 10, 16, 28, 52, 100, 196:

now the excesses of each of these numbers above the first are,

3, 3, 6, 12, 24, 48, 96:

a series in which each term (after the first,) is double of the preceding one. Hence, the distances of the planets conform to a series following this law, (Bode's law, as it is termed.) And though the law is by no means exact, yet it was so far considered a probable expression of a general fact, that the deviation from this law, in the interval between Mars and Jupiter, was the principal cause which led first to the suspicion of a planet interposed in the seemingly vacant space; and thus led to the discovery of the planetoids, which really occupy that region. It is true, that the law is found not to hold, in the case of the newly-discovered planet Neptune; for his distance from the Sun, which according to this law, should be 388, is really only 300, 30 times the Earth's distance, instead of 39 times. Still, Bode's law has a comprehensive approximate reality in the Solar System, sufficient to make it a strong recommendation of any hypothesis of the origin of the system, that it shall account for this law. This, however, the nebular hypothesis does not.