Abundance of the chemical elements in the Sun and outer planets is similar to that in the universe. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Lighter silicates of aluminum are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core. The abundance of elements in specialized environments, such as atmospheres, or
Batman (Earth-Two) his son about being killed in crime alley that night. Dick Grayson would also take up the mantle during "Earth 2:Earth's End and Earth 2:Society". Helena would later don the mantle after Dick retired at the end of the Society series. Batman's origin and history is essentially similar to the Earth-One version of the character, but events unfold in more of a real-time fashion. For example, the Batman makes his debut in 1939, meets Robin, the Joker, Catwoman and Clayface at various points in 1940, the Penguin in 1941, Two-Face in 1942, etc. These dates reflect the publishing dates of