Simplify the following text for a Grade 10 native English-speaking person.
Original: Sagan married three times ; the biologist Lynn Margulis ( mother of Dorion Sagan ) in 1957 , artist Linda Salzman in 1968 , and author Ann Druyan in 1981 , to whom he was married until his death .
Simplified: Sagan was married three times : in 1957 , to biologist Lynn Margulis , mother of Dorion Sagan and Jeremy Sagan ; in 1968 , to artist Linda Salzman , mother of Nick Sagan ; and in 1981 , to author Ann Druyan , mother of Alexandra Rachel ( Sasha ) Sagan and Samuel Democritus Sagan . His marriage to Druyan continued until his death in 1996 .