AST-1001 Lecture Notes - Lecture 8: Escape Velocity, Tharsis, Hesperian
Document Summary
Me(cid:396)(cid:272)u(cid:396)y"s (cid:396)otatio(cid:374) is i(cid:374) (cid:396)eso(cid:374)a(cid:374)(cid:272)e with its o(cid:396)(cid:271)it. The surface of mercury is marked by great curved cliffs called lobate scarps. It is heavily battered with craters, including some large basins. Most craters were formed after era of heavy bombardment. Mercury is more than 60% denser than the moon. Unclear how a planet that formed so close to the sun could contain so much sulfur. Mag(cid:374)eti(cid:272) field is o(cid:374)ly a(cid:271)out (cid:1005). (cid:1005)% as st(cid:396)o(cid:374)g as ea(cid:396)th"s. Me(cid:396)(cid:272)u(cid:396)y"s i(cid:374)te(cid:396)io(cid:396) (cid:272)o(cid:374)tai(cid:374)s a la(cid:396)ge (cid:272)o(cid:396)e of de(cid:374)se li(cid:395)uid (cid:373)etals, (cid:373)ostly i(cid:396)o(cid:374), whi(cid:272)h should produce a larger magnetic field. Only heavy elements were condensed out of mercury. Later bombardment removed lighter rocks from the surface. Ejecta did not spread as far secondary impacts are less spread out over surface. Cooling interior contracted and crust broke to form lobate scarps. Has a similar average density as earth. The surface is very dry and hot. Clouds constantly prevent visual observations of the surface.
