Its apparently low density suggests that , unlike 10 Hygiea , 704 Interamnia and 52 Europa , Euphrosyne is a loosely-packed rubble pile ( an asteroid that has been broken apart by a collision with all the pieces pulled together by gravity ) . Its low density strongly suggests that , unlike 10 Hygiea , 704 Interamnia and 511 Davida , Euphrosyne is a loosely-packed rubble pile .