NEPTUNE

The past century was remarkable for the discovery of this new planet: Neptune. How it was accomplished is a matter of great interest. In 1820, it was found that Uranus was not following its computed path. Adams, of Cambridge, and Leverrier, of Paris, each independently took up this question, and, assuming that this perturbation was due to the presence of a planet still more remote from the sun (which had been hinted at in 1830 by Bessel) they set to work to calculate its position in the heavens. They finished this at about the same time, arriving at practically the same conclusions. Adams’ results were first submitted to the Astronomer Royal, who set them aside without consideration until too late. Leverrier sent his conclusions to a German astronomer, Galle, who found the planet the first evening he looked for it, September 23, 1846.

Neptune is the furthest known planet of our solar system; it is a very large body, having a diameter of about 37,000 miles. It revolves round the sun in an immense orbit which it takes 164 years to complete. Its mean distance from the Sun is nearly 2,800,000,000 miles—a majestic sweep through the heavens! Relatively little is known as to the physical conditions of Neptune, owing to its immense distance, and its relatively small size. At least one satellite is known to exist. The temperature on Neptune must be extremely low, owing to its distance from the sun, whose rays would be exceedingly feeble at that great distance.