Download Planetary Sciences

ASTRONOMY 8850:
Planetary Sciences
Why Sciences?
How to do well in
Planetary Sciences
1. show up to class … and be present
2. participate in class
3. get/borrow the book Planetary Sciences by de Pater and Lissauer
4. find course website: www.astro.gsu.edu/~thenry/PLANETS
5. find Icarus online (or in the library)
6. choose 3 planetary topic(s) you are most interested in --- start project EARLY
7. do homework --- Solar System Explorers, quizzes, etc.
8. NAIL THE SEMESTER PROJECT
Solar System Explorers 01
Find Icarus online (or in the library).
Choose an article relevant to one of your 3 topics.
Print out the first page of the article.
Turn in single page (with your name on it) at the beginning of
class TUESDAY, January 20.
Get 5 points in Solar System Explorers.
Solar System Inventory
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stars
1
planets
8
moons
172a
ring systems
4 (+1?)
minor planets
670,480
Centaurs
295
Trans-Neptunian Objects 1,644
comets
3,319b
dust
(JPL 2015 JAN 12)
(JPL
(JPL
(JPL
(JPL
a
2015 JAN 12)
2015 JAN 12)
2015 JAN 12)
2015 JAN 12)
add 5 for Pluto
b any type
Nomenclature
• terrestrials
Mercury, Venus, Earth, Mars
many moons
• jovians
gas giants
Jupiter, Saturn
ice giants
Uranus, Neptune
• minor planets
asteroids
Main Belt
Near-Earth Objects (NEOs)
Trojans (and Greeks and Hildas)
Trans-Neptunian Objects (TNOs)
Plutinos
(Classical) Kuiper Belt Objects (KBOs)
Centaurs
Scattered Disk Objects (SDOs)
comets
Solar Family
How are they different?
Jovians and Terrestrials
Planet Spacing
Planetary Sciences
8
Planet Orbits
Planetary Sciences
The 7 Dwarfs (+ interlopers)
X
X X
Terrestrial Planet Surface
Surface Variability
Planetary Sciences
12
Jovian Planet “Surface”
…we can land/work on surfaces
Planetary Sciences
Planet Characteristics
Characteristic
location
spacing
mass
size
density
composition
surface
albedo
rotation
magnetics
moons
rings
Terrestrial
0.4-1.5 AU
close
0.05-1.0 Earths
0.4-1.0 Earth radii
3.9-5.5 g/cm3
rocky
solid
0.1-0.7
slow
none/weak
none/few
none
Jovian
5.2-30.1 AU
wide
14.5-318 Earths
3.9-11.2 Earth radii
0.7-1.6 g/cm3
gaseous/icy
any?
0.4-0.5
fast
strong (integrated)
many
all
obliquities (tilts)
bizarre bar magnets
Planetary Sciences
17
magnetospheres
Earth’s is strongest terrestrial
surface mag field = 0.3 G
mag moment = 8x1025 G/cm3
enough to protect us from charged particles
Mercury’s, Ganymede’s wimpy
Venus?, Io, Europa, Callisto induced
Mars’ patchy crustal
Jupiter’s is strongest jovian
surface mag field = 4.3 G
mag moment = 20000X Earths
Io plasma torus complicates
affects all Galilean satellites
Sat/Ura/Nep surface mag fields
similar strength to Earth’s
Jupiter’s magnetotail
Planetary Sciences
trends in the Solar System
size with distance from the Sun
composition with distance
spacing of planets with distance
# moons with planet mass
magnetic fields with mass
rotation speeds with mass
non-trends in the Solar System
surface gravities not radically different
obliquities do not behave
7 large moons are worlds of their own:
Moon, Io, Europa, Ganymede, Callisto, Titan, Triton
…………………………