Ken Lake , who mentions a theory that Mars was thought, in the 17th century, to have two moons because the Earth had one and Jupiter had four (that they could see).
(they; could see; ) (Mars; was thought; ) (Ken Lake; to have; two moons; because the Earth had one and Jupiter had four (that they could see) Context(Ken Lake to have,List([0, 84))):(Ken Lake; to have two moons mentions; a theory that Mars was thought, in the 17th century) (the Earth; had; one) (Jupiter; had; four (that they could see)
Ken Lake to have,List([0, 84))
they Mars Ken Lake Ken Lake the Earth Jupiter
could see was thought to have to have two moons mentions had had
two moons because the Earth had one and Jupiter had four (that they could see
a theory that Mars was thought, in the 17th century
one
four (that they could see