unfamiliar territory

an area of knowledge unknown to the speaker. We are in unfamiliar territory and I don't know the answer. Astronomy is unfamiliar territory for me, and I cannot answer any questions about the stars.

Common Names:

Name	Pronounced	Usage
Lazer	-	Yiddish
Victorino	beek-to-REE-no (Spanish)	Spanish, Portuguese
Deror	-	Hebrew
Martyn	-	Welsh, Ukrainian
Montse	-	Catalan
Muirne	-	Irish Mythology