Simplify the following text for a Grade 7 native English-speaking person.
Original: Dactyl is only 1.4 km in diameter . Some researchers believe that Dactyl formed from debris blown off from Ida because of cratering , while others suggest that Ida and Dactyl formed as a pair a billion or more years ago when Ida 's parent body was disrupted .
Simplified: Dactyl 's orbit around Ida is not precisely known .