Conversation so far:
how old is the character abby on ncis
The character Abby from NCIS is shown to be 10 years old in the early 1980s, implying that she was born in the early 1970s.
who was another main character on the ncis besides abby?
Mark Harmon is another main character from NCIS.
is ncis still active?
NCIS was renewed for a seventeenth season on April 11, 2019, which premiered on September 24, 2019.

Question: when did the show first air?
Self-contained rewrite: when did ncis first air?