Download Chapter 12 Slides.

ASTR 2310: Chapter 12
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The Solar System in Perspective

Comparative Planetology (“Lessons”)

Origin of the Solar System

Exoplanets
– Detection
– Properties
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See Exoplanet Resources posted at
http://www.mikebrotherton.com/?p=2168
ASTR 2310: Chapter 12
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

Comparative Planetology
Lesson 1: Surfaces of planets are shaped by competing
internal and external mechanisms (e.g. volcanism vs.
cratering).
Lesson 2: More massive, colder planets are better able to
retain atmospheres (e.g., Pluto, Moon, Mercury, Mars, Venus,
Earth, Jovian planets, in increasing mass).
ASTR 2310: Chapter 12
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

Comparative Planetology
Lesson 3: Giant satellites of Jovian planets show patterns
consistent with our ideas about formation of the planets (e.g.
they're mini-solar systems).
Lesson 4: Many unusual features of the solar system can be
attributed to giant impacts (Earth's moon, Triton, Uranus,
Venus).
ASTR 2310: Chapter 12

Origin of the Solar System
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Emerging picture of a rotating protoplanetary disk explains
– Planets nearly in same plane
– Sun's equator is close to this plane.
– Planetary orbits are nearly circular.
– Planets orbit in same direction.
– Most planets and sun rotate in same direction as the orbital
motion.
ASTR 2310: Chapter 12
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Origin of the Solar System
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Other issues also addressed
– Nature of small bodies – left overs, with many moons
formed around Jovian planets, smallest stuff replenished
from collisions
– Differences in chemical composition (metal, stone, ices,
volatiles)
– Rings around Jovian planets (failed moons or destroyed
moons)
– Chemical differentiation of terrestrial planets (radioactivity)
ASTR 2310: Chapter 12
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Exoplanets

Detection
– Difficulties
– Center of Mass Wobbles
– Transit Method (eclipses)
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Properties
– Not quite like solar system planets
• In part because different things can happen
• In part because of selection effects