interstellar distance

21 LETTERS · STARTS WITH I

interstellar distance is a valid 21-letter word worth 23 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

I1N1T1E1R1S1T1E1L1L1A1R1D2I1S1T1A1N1C3E1

1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 2 + 1 + 1 + 1 + 1 + 1 + 3 + 1 =23 PTS

DOUBLE WORD → 46TRIPLE WORD → 69

MEANING

What does interstellar distance mean?