Mantle (geology) might possibly be exposed in the South Pole-Aitken basin and/or the Crisium basin. The lunar mantle contains a seismic discontinuity at ~500 km depth, most likely related to a change in composition. Titan and Triton each have a mantle made of ice or other solid volatile substances. Some of the largest asteroids have mantles; for example, Vesta has a silicate mantle similar in composition to diogenite meteorites. Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest
Planetary core has an observed magnetic field, which is believed to be generated within its metallic core. Mercury's core occupies 85% of the planet's radius, making it the largest core relative to the size of the planet in the Solar System; this indicates that much of Mercury's surface may have been lost early in the Solar System's history. Mercury has a solid silicate crust and mantle overlying a solid iron sulfide outer core layer, followed by a deeper liquid core layer, and then a possible solid inner core making a third layer. The composition of Venus' core varies significantly depending on the