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
Robin (Earth-Two) He discovered from Helena that her father was influenced by his terminal cancer during his writing of the journal. In the limited series "Crisis on Infinite Earths", the multiverse as we know it is destroyed. Among the lost worlds is Earth-Two. Following this crisis Earth Two "never existed" and retroactively removed Earth-Two Robin from history, blending elements of his past with Earth-One, effectively creating a new modern continuity. Robin, along with the Huntress died while protecting innocents at the hands of shadow demons from the Anti-Matter Universe. However, a version of this Robin and Huntress existed on some plane of