Page:The sidereal messenger of Galileo Galilei.pdf/93

 were present, one on the east, distant 10′ from Jupiter; the other was on the west, at a distance of 6′ (Fig. 57). The eastern satellite was slightly smaller than the western. At the fifth hour three satellites were visible; for, besides the two already noticed, a third satellite was in view, on the west, near Jupiter, very small, which previously had been hidden behind Jupiter, and it was at a distance of 1′ from the planet (Fig. 58).

But the satellite on the east was seen to be further off than before, being at a distance of 11′ from Jupiter. On this night, for the first time, I determined to observe the motion of Jupiter and the adjacent planets (his satellites) along the zodiac, by reference to some fixed star; for there was a fixed star in view, eastwards of Jupiter, at a distance of 11′ from the satellite on the east, and a little to the south, in the following manner (Fig. 59).

Feb. 27: 1 h. 4 m.—The satellites appeared in the following configuration. The satellite furthest to the east was at a distance of 10′ from Jupiter; the next in order was near Jupiter, being at a distance of 0′ 30″ from the planet. The next satellite was on the western side, at a distance of 2′ 30″ from Jupiter; and the satellite further to the west was at a distance of 1′ from this. The two satellites near to Jupiter