(?) and viii., and the satellite of Neptune.); while, to make the argument complete, the planets, so far as they can be observed, rotate on their axes in the same manner.
But the same relation does not hold of a satellite the mass of whose primary is not regarded as an absolutely known quantity, or of a binary star.
ELONGATION, strictly "lengthening"; in astronomy, the apparent angular distance of a heavenly body from its centre of motion, as seen from the earth; designating especially the angular distance of the planet Mercury or Venus from the sun, or the apparent angle between a satellite and its primary.
The immediate results of the clearer definition obtained were the detection of a satellite to Saturn (the sixth in order of distance from its primary), and the resolution into their true form of the abnormal appendages to that planet.