They actually met in 1997 or '98 when Janet was promoting The Velvet Rope. I read a brilliant Rolling Stone article from that time in which the author basically followed Janet for a few days (or weeks?) and delved into her emotional issues. Amusingly, she went to an event and Mariah came up to her and said "Hi Miss Jackson, I'm Mariah," Janet said "I know," and I think they posed for pics.