- Mesarthim (stars.astro.illinois.edu)
MESARTHIM (Gamma Arietis). Shining third among the stars of the flat triangle that make the classical figure of Aries, the Ram (for that reason gaining the Gamma designation), Mesarthim actually takes fourth place in the constellation after non-named 41 Arietis, which glows softly off to the northeast.
- Extrusive rock (Wikipedia)
Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contrast, intrusive rock refers to rocks formed by magma which cools below the surface.