Simplify the following text for a Grade 6 native English-speaking person.
Original: The Cybele asteroids are a group of asteroids in the asteroid belt with an orbital radius usually between 3.27 AU and 3.7 AU , with an orbital eccentricity less than 0.3 , and an inclination less than 25 Â .
Simplified: Cybele asteroids are a group of asteroids in the outer main belt with a semi-major axis between 3.27 AU and 3.7 AU , an eccentricity less than 0.3 , and an inclination less than 25 Â .