Complex sentence: In the vicinity of Montes Secchi is Mount Marilyn is a distinctly triangular mountain formation, it was named in 1968 by Apollo 8 astronaut Jim Lovell, after his wife.
Split into simpler sentences: In the vicinity of Montes Secchi is Mount Marilyn, a distinctly triangular mountain formation. It was named in 1968 by Apollo 8 astronaut Jim Lovell, after his wife.