A great difference once thought to exist between Mars and the other planets was that he had no moons; but during the night of the 16th of August, Professor Hall, of the U.S. Naval Observatory at Washington, D.C., actually saw through his telescope that Mars has a moon. On the 18th of August another was seen, smaller than the first and nearer to the planet. The larger satellite is believed to be not more than ten miles in diameter: it is less than 12,000 miles distant from its primary, and its period of revolution about it is 30 hours 14 minutes. The distance of the smaller moon is 3,300 miles, and its period 7 hours 38 minutes. There is no doubt that these newly found celestial bodies are the smallest known.
From measurements made by Professor Hall, it is found, with a near approach to certainty, that the mass of Mars is equal to 1-3,090,000th part of the mass of the sun.

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