Charon is unusual in that it is the largest moon with respect to its primary planet in the Solar System (a distinction once held by Earth's Moon ).
(Charon; is; unusual) (it; is; the largest moon with respect to its primary planet in the Solar System) (a distinction; held; by Earth's Moon; T:once)
Charon it a distinction
is is held
unusual
the largest moon with respect to its primary planet in the Solar System
by Earth's Moon T:once