Page:The Music of the Spheres.djvu/282

 most exceedingly rapid flight, it would seem that there would be some reason in naming it Phobos (Fear), after one of Mars' attendants. On account of its nearness to the surface of Mars, Phobos would appear to a Martian about the same size as our moon does to us.

The other moon, which was named Deimos (Terror), is about 14 miles in diameter and is 12,500 miles from the planet. Its period is also very short, being only 30 hours and 18 minutes. Since this period is only a few hours more than the rotation period of Mars, the moon moves very slowly across the sky, remaining continuously above the horizon of any given place on the planet for more than 60 hours. It has been computed that these two small moons would cause 1400 eclipses of the sun a year, as seen from Mars. They are the smallest objects visible in the sky, as seen from earth.

Our month of March, as well as this fiery-hued planet, was named after the War-god. Since Tuesday was also named after the War-god, it might be well to mention here how the other days and months obtained their names.

In the early days of Astrology, a "science" which was based on legends and myths, the names of the five planets then known were given to the days of the week. Apollo, the Sun-god, gave his name to Sunday, and his sister, Goddess Diana, to Monday, and these two days retained their names, but the days which followed those named for the sun and moon later became Germanized, as it were, or the names of the originally imported gods translated into those of the Germanic divinities. Thus the name of the Northern Sword-god Tyr, who resembles the Roman War-god Mars, was given the day of the week held sacred to Mars, now known as Tuesday, or Tiu's day, Mercury's day became Wodan's or Wednesday, Jove's day was called Thor's or Thursday, and the day of Venus transformed into Friday, the day of