67. Our Earth appears almost as big to Mars as Venus does to us, and at
Mars it is never seen above 48 degrees from the Sun; sometimes it
appears to pass over the Disc of the Sun, and so do Mercury and Venus:
but Mercury can never be seen from Mars by such eyes as ours, unassisted
by proper instruments; and Venus will be as seldom seen as we see
Mercury. Jupiter and Saturn are as visible to Mars as to us. His Axis is
perpendicular to the Ecliptic, and his Orbit is 2 degrees inclined to
it.
[Sidenote: Jupiter.