Page:The Music of the Spheres.djvu/249

 known celestial body with the exception of the moon, exhibits a rapid variation in the brilliancy of its light. It is thought that this may be due to a rough, uneven surface with unequal reflecting power, for Eros is no more than a huge rock only 20 miles across. It has also been suggested that perhaps Eros consists of two bodies revolving close together so that one body eclipses the other in certain parts of its orbit, or again, it may be an angular body, not round at all! Many of the planetoids are smaller than Eros, some being only a few miles across.

Thus a thousand mysterious little worlds of assorted shapes and sizes roll along on their individual pathways in the great space between the orbit of Mars and the orbit of the earth. The bright light of Vesta, the dull glow of Ceres and the variable brilliancy of Eros lightly suggest the interest with which further observations and study may invest each tiny planet, as larger and more powerful telescopes are constructed.

A comet, in olden times, was an object of terror and dread and was regarded as an omen of pestilence and war. Searching through ancient records, incidents without number could be narrated to show that the malicious influence of some comet had caused—