It seems that Adrastea is the most copious source of this ring material, as evidenced by the densest ring (the Main Ring) being located at and within Adrastea's orbit.[11] More precisely, the orbit of Adrastea lies near the outer edge of Jupiter's Main Ring.[12] The exact extent of visible ring material depends on the phase angle of the images: in forward-scattered light Adrastea is firmly outside the Main Ring,[12] but in back-scattered light (which reveals much bigger particles) there appears to also be a narrow ringlet outside Adrastea's orbit.[4]