The 'We Found Love' singer explained that her father Ronald Fenty made her keep a lookout for aliens while sitting on their front porch in Bridgetown, Barbados.
"My dad used to make me sit outside on the steps all night long looking for UFOs flying by, and I had to do that for years," she said.
"I didn't see any but I saw a falling star once and I was like, 'Yessss, dad! Come and see, it just darted'."
Rihanna fights aliens in her first movie role as Petty Officer Cora Raikes in Battleship, which is released in UK cinemas on April 11 and in the US on May 18.
The star recently described her Hollywood debut as "nerve-wracking" and "really scary".
Rihanna has also defended herself against criticism that she is a bad role model for young women.
> Rihanna: 'I had to learn to be comfortable with my body'
Watch Rihanna at the Battleship press conference below: