ASTR 101 Lecture Notes - Lecture 31: Planetary Geology, Radioactive Decay, Lithosphere

• School: Queen's University
• Department: Physics, Engineering Physics and Astronomy
• Course: ASTR 101
• Professor: Majd Abdelqader

Document Summary

Planetary geology: earth and the other terrestrial worlds. Core: highest density, nickel and iron. Mantle: moderate density, silicon oxygen, etc. Crust: lowest density, granite, basalt, etc, rigid lithosphere part of crust and mantle. Applyi(cid:374)g (cid:449)hat (cid:449)e ha(cid:448)e lear(cid:374)ed a(cid:271)out earth"s i(cid:374)terior to other pla(cid:374)ets tells us (cid:449)hat their interiors are probably like. A pla(cid:374)et"s outer layer of (cid:272)ool, rigid ro(cid:272)k is (cid:272)alled the lithosphere. It (cid:862)floats(cid:863) o(cid:374) the (cid:449)ar(cid:373)er, softer ro(cid:272)k that lies (cid:271)e(cid:374)eath. Vi(cid:271)ratio(cid:374)s that tra(cid:448)el through earth"s i(cid:374)terior tells us what earth is like on the inside. Cooling of planetary interiors: convections: transports heat as hot material rises and cool material falls, conduction: transfers heat from hot material to cool material, radiation: sends energy into space, once it reaches the surface. Smaller worlds cool off faster and harden earlier. Surface area to volume ratio surface are tell you how affective the radiation is larger objects have a smaller ratio of cool.