AST 101 Final Exam Study Guide – Astronomy Exam Review & Notes

ast101/./final/./exam


Apply/./the/./concept/./of/./comparative/./planetology/./(Terrestrial/./planets)/./-
/./correct/./answer/./✔ ✔
Comparative/./planetology/./=/./the/./study/./of/./the/./solar/./system/./by/./examini
ng/./and/./understanding/./similarities/./and/./differences/./among/./worlds


The/./surfaces/./of/./all/./five/./terrestrial/./worlds/./-
/./Mercury,/./Venus,/./Earth,/./the/./Moon,/./and/./Mars/./-


/./must/./have/./looked/./quite/./similar/./when/./they/./were/./young/./since/./all/./are/./


made/./of/./rocky/./material/./and/./were/./subjected/./to/./the/./impacts/./of/./the/./heav
y/./bombardment././The/./great/./differences/./in/./their/./current/./appearances/./mu
st/./thus/./be/./the/./result/./of/./changes/./that/./have/./occurred/./through/./time


Mercury/./and/./the/./Moon/./show/./scars/./of/./their/./abttering/./during/./the/./heavy/.
/bombardment:/./they/./are/./densely/./covered/./by/./craters,/./except/./in/./areas/./tha


t/./appear/./to/./be/./volcanic/./plains


Bulges/./and/./volcanoes/./dot/./the/./surface/./of/./venus

,Mars/./has/./the/./solar/./system's/./largest/./volcanoes,/./a/./huge/./canyon/./cutting/./a
cross/./its/./surface,/./and/./many/./features/./that/./appear/./to/./have/./been/./shaped/./b
y/./liquid/./water,/./but/./are/./not/./dry


Earth/./has/./surface/./features/./similar/./to/./all/./those/./on/./the/./other/./terrestrial/./
worlds,/./and/./more/./-
/./including/./a/./unique/./layer/./of/./living/./organisms/./that/./covers/./almost/./the/./e


ntire/./surface/./of/./the/./planet


Compare/./and/./contrast/./Mercury/./and/./the/./Moon/./in/./terms/./of/./their/./surface
/./features,/./compositions,/./masses,/./and/./origins/./-/./correct/./answer/./✔ ✔
Surface/./features:
-
both/./are/./densely/./covered/./by/./craters,/./except/./in/./areas/./that/./appear/./to/./be/
/./


./volcanic/./plains



-
Moon:/./The/./lunar/./surface/./is/./a/./combination/./of/./extremely/./ancient,/./heav
/./


ily/./cratered/./terrain/./and/./somewhat/./younger/./lava/./plains/./called/./the/./lunar/.
/maria;/./Some/./small/./tectonic/./feature/./features/./are/./also/./present;/./The/./Moo


n/./lacks/./erosion/./because/./is/./has/./so/./little/./atmosphere
-
Mercury:/./Mercury's/./surface/./resembles/./that/./of/./the/./Moon/./in/./being/./shap
ed/./by/./impact/./cratering/./and/./volcanism;/./It/./also/./has/./tremendous/./tectonic/.
/cliffs/./that/./probably/./formed/./when/./the/./whole/./planet/./cooled/./and/./contract


ed/./in/./size

,Compositions:
-/./composed/./largely/./of/./metal/./and/./rock
-/./layered/./by/./density/./-/./core,/./mantle,/./crust
-
Mercury/./has/./a/./huge/./core,/./and/./Mercury/./and/./the/./Moon/./have/./the/./thicke
/./


st/./lithospheres/./(smaller/./worlds/./tend/./to/./have/./thicker/./lithospheres)
-
The/./crust/./and/./part/./of/./the/./mantle/./together/./make/./up/./the/./rigid/./lithosphe
/./


re/./(In/./general,/./a/./thinner/./lithosphere/./allows/./more/./geological/./activity)


Masses:
-/./smallest/./of/./the/./terrestrial/./worlds/./in/./size
-/./Mercury/./=/./0.055/./Earth/./mass
-/./Moon/./=/./0.073/./Earth/./mass
-/./least/./massive/./of/./the/./terrestrial/./worlds/./


Origins:
-
Mercury's/./core/./seems/./surprisingly/./big,/./while/./the/./Moon's/./core/./seems/./
/./


surprisingly/./small/./(which/./is/./why/./scientists/./suspect/./that/./giant/./impacts/./
affected/./both/./worlds)
-
/./ In/./Mercury's/./case,/./a/./giant/./impact/./that/./blasted/./away/./its/./outer/./rocky/./la

, yers/./while/./leaving/./its/./core/./intact/./could/./explain/./why/./the/./core/./is/./so/./larg
e/./compared/./to/./the/./rest/./of/./the/./planet
-
The/./Moon's/./small/./core/./can/./be/./explained/./by/./assuming/./the/./Moon/./form
/./


ed/./from/./debris/./blasted/./out/./of/./Earth's/./rocky/./outer/./layers:/./the/./debris/./wo
uld/./have/./contained/./relatively/./little/./high-
density/./metal/./and/./thus/./would/./have/./accreted/./into/./an/./object/./with/./a/./very/
./small/./metal/./core




Describe/./the/./mechanisms/./by/./which/./planets/./produce/./and/./lose/./heat;/./exp
lain/./which/./methods/./dominate/./the/./energy/./balance/./of/./each/./planet/./-
/./correct/./answer/./✔ ✔ Produce/./heat:

-
Accretion/./=/./Gravitational/./potential/./energy/./is/./converted/./into/./kinetic/./e
/./


nergy,/./which/./upon/./impact/./is/./converted/./into/./thermal/./energy././Accretion/.
/deposits/./energy/./brought/./in/./from/./afar/./by/./colliding/./planetesimals././As/./a/./


planetesimal/./approaches/./a/./forming/./planet,/./its/./gravitational/./potential/./en
ergy/./is/./converted/./to/./kinetic/./energy,/./causing/./it/./to/./accelerate././Upon/./imp
act,/./much/./of/./the/./kinetic/./energy/./is/./converted/./into/./heat,/./adding/./to/./teh/./t
hermal/./energy/./of/./the/./planet.
-
Differentiation/./=/./Light/./materials/./rise/./to/./the/./surface,/./while/./dense/./mate
/./


rials/./fall/./to/./the/./core,/./converting/./gravitational/./potential/./energy/./into/./ther
mal/./energy
-/./Radioactive/./decay/./=/./Mass-
energy/./contained/./in/./nuclei/./is/./converted/./into/./thermal/./energy/./(major/./so
urce/./of/./heat/./today)