An introduction to astronomy: designed as a text-book for the use of students in college. By Denison Olmsted ...

JuP'rrlI:~~. i201
occultation. Bu:t if the earth passes beyond 1), to C, tllen
Jupiter is wvest of opposition; for tlhe place of ol)position would
be in 8(0 produced. And now, each satellite passes behind the
planct, and thus suflfers occultation before it reaches the
F'ig. 66.
shadow, alnd is eclipsed; and, in entering the shadow, the,satellites are genorally blehid the planet, while in leaving it,
they are in sighllt; so that occultations precede eclipses. T11
fourtll satellite often enters and leaves the shadow oin the same
side of the planlet, and sometimecs the third, and possibly the
secolld, but this is never true of the first..
336. -lrWhen one of the satellites is passing between Jupiter
and the sun, it casts its shadow lpon its primary, as the moonl
does oin the earth ill a solar eclipse, whlich is seenll by the telQsco)e, traveling across flte disk of Jupiter, as tlle shadow of the
loonll woulld be seen to traverse the earth by a spectator favorably situated in 8sace. Wllen. Jupiter is east of opposition,
the earth bceing at A (ig.!, 65), the shadow strikes t.le disk of
the, planet, before the satellite itself is seen upon it, because
the satellite will evidently come bet n S e and Jupiter
sooner than it does between A anld Jupiter. Just the reverse of this takes place, when the ealrth is at C, that is,
lwhen Julliter is west of opposition. A satellite will thel colme
letwceen C and the pllanet, sooner than between S and the
planct. A\We do not usually see the satellite itself proje-ted on