The Jovian Planet Systems - PowerPoint PPT Presentation

Loading...

PPT – The Jovian Planet Systems PowerPoint presentation | free to download - id: 724fb1-ZWI3M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

The Jovian Planet Systems

Description:

The Second way to Lose Atmosphere Impact Cratering. Big comets and asteroids hitting the planet will deposit a lot of kinetic energy which becomes heat, blowing ... – PowerPoint PPT presentation

Number of Views:57
Avg rating:3.0/5.0
Slides: 122
Provided by: R627
Learn more at: http://www.cabrillo.edu
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: The Jovian Planet Systems


1
The Jovian Planet Systems
  • TOTALLY different planets than our familiar next
    door neighbors!
  • The formed beyond the frost line so ices could
    form and seed the early stages of agglomeration.
    Theres a lot more ice-type raw material than
    rock-type raw material, so you get bigger planets!

2
Remember How a Planet Retains an Atmosphere
  • Surface gravity must be high enough and
  • surface temperature must be low enough, that the
    atmosphere molecules dont leak away during the
    4.6 billion years since formation.
  • Also,Jovian Planets are so distant and so cold,
    they formed from seeds of ice, MUCH more common
    than rocky seeds
  • Net Result Jovians are mostly atmosphere or (in
    Jupiters case) liquid hydrogen

3
Remember the Two Ways a Planet Loses Atmosphere
FirstLeakage!
  • Lighter molecules move faster, because on average
    Kinetic Energy Thermal Energy
  • (½)mltvgt2 (3/2)kT
  • For a given temperature, higher mass molecule
    means lower velocity molecule, is what this
    equation is telling us
  • Molecules are continually bouncing off of each
    other and changing their speed, but if the
    average speed is higher, a few may be speedy
    enough to escape the planets gravity.
  • So the lighter gasses leak away more quickly over
    time
  • So. Slow leak! Like air from a bicycle tire
  • Hydrogen and Helium 97 of the mass of the
    solar nebula, and these are the lightest and
    easiest molecules to lose.
  • But they are NOT lost by Jupiter, Saturn, Uranus
    and Neptune. Mass is high, gravity is high,
    escape velocity is high, and temperature is low
    so molecular velocities, even H2 and He, are also
    low.

4
The Second way to Lose Atmosphere
  • Impact Cratering Big comets and asteroids
    hitting the planet will deposit a lot of kinetic
    energy which becomes heat, blowing off a
    significant amount of atmosphere all at once.
  • This is not much of an issue for the outer
    planets, who have high gravity and very high
    mass, so a give impact is unlikely to unbind much
    atmosphere

5
The Outer Plants Hydrogen/Helium Giants
  • 97 of early solar nebula was hydrogen and
    helium, roughly the composition of the outer
    planets
  • Cold temperatures, high mass allow these light
    atoms to be held by gravity for these 4.6 billion
    years
  • Rocky cores surrounded by deep layers of H, He.

6
Jupiter,Saturn,Uranus,Neptune lineup
7
Jupiter layers
8
Jupiter is a Stormy Planet
  • High temperatures deep inside mean strong
    convective flow in the atmosphere.
  • The rapid rotation (day 12 hrs) and large
    diameter means very strong velocity gradient from
    equator to poles.
  • So, strong Coriolis force, making atmospheric
    motions turn into circulations like hurricanes
  • Result is lots of big storms

9
Jupiter storms
10
(No Transcript)
11
The Great Red Spot
  • As big as 3 Earths side-by-side
  • This is a high pressure anti-cyclone
  • Jupiters storms usually last months or maybe a
    year or so, but the Great Red Spot has been on
    Jupiter since we first put a telescope on it to
    see.

12
Jupiter redspots
13
(No Transcript)
14
GRS storms
15
Jupiter gives off more heat than it receives from
the sun. Its HOT under that cold atmosphere
  • Why? Heat of formation takes a LONG time to
    dissipate, but mainly its because it is still
    slowly collapsing, converting gravitational
    potential energy into heat
  • You can see the hotter layers in infrared
    pictures

16
Jupiter IR, excess heat
17
Jupiter has the right ingredients for a Strong
Magnetic Field
  • Rapid rotation
  • Hot interior and strong temperature gradient
    driving convection of
  • An electrically conducting interior in this
    case, liquid hydrogen under so much pressure it
    behaves like a metal.
  • The result the most powerful magnetic field of
    any planet by far.

18
(No Transcript)
19
Jupiters Aurora
20
The strong convection leads to Lightening
21
(No Transcript)
22
(No Transcript)
23
Jupiter ring
24
Jupiters Ring, Seen Edge-on
25
Origin of Jupiters Ring?
  • Might be the remnants of a comet (icy dirtball)
    that was captured into an orbit and the ices
    eroded away by the ions trapped in the magnetic
    field
  • But current thinking is that its material
    launched into orbit around Jupiter by Ios
    volcanoes. The ring is made up of micron-sized
    particles, like volcanic ash.

26
magnetosphere
27
Jupiters Moons 63 at last count
  • The 4 big ones are roughly the size of our own
    moon 1500 3000 miles across
  • From closer to farther, they are Io, Europa,
    Ganymede and Callisto
  • Ios orbit is a bit elliptical, and only a couple
    Jupiter diameters away from Jupiter this has a
    huge effect on the properties of this little moon

28
Jupiter Io
29
Jupiters huge gravity and the closeness of Io
means it experiences strong tidal stretching
  • This tidal force varies from weaker to stronger
    as Io goes from closer to farther from Jupiter in
    its slightly elliptical orbit. This rhythmic
    squeezing and stretching of the moon heats the
    interior tidal friction
  • Its surprisingly effective. The volcanoes have
    vent temperatures of 2000F, melting sulfur, a
    relatively light element that is rich in the
    upper layers, and vaporizing any water or other
    icey type materials.

30
Io globe
31
Io cutaway
32
Io globe closer in
33
Io pele
34
Io volcano on limb
35
Io volcano
36
Io volcano closeup
37
(No Transcript)
38
Io surface hi res
39
Summary on Io
  • Io is stretched more, then less, then more, then
    lessetc for each and every 42hr orbit.
  • This converts orbital kinetic energy into thermal
    energy, heating the interior above the melting
    point of sulfur (239F or 115C), and it burbles up
    through cracks to make volcanoes.
  • Constant volcanic eruptions quickly fill in all
    craters that may have existed
  • Volcanic particles can escape Ios weak gravity.
    And eventually friction decays the orbit and the
    material settles onto Jupiter, coloring its
    clouds.

40
Europa Also tidally heated, but less so
  • It was not so hot as to evaporate water away.
    Water is a very common molecule.
  • Europa is an arctic world of salt water covered
    by ice
  • Cracks show characteristics of salt-water
    pressure ridges
  • Intriguing salt water ocean warm enough to
    support life, is what the evidence suggests.

41
Europa interior cutaway
42
(No Transcript)
43
(No Transcript)
44
Pressure ridges, sharpened by image processing.
The Reddish color likely mineral salt evaporate
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
Strike-Slip Faults Earth vs. Europa
49
(No Transcript)
50
One model- thermal vents from the hot core drive
convection in the ocean, driving tectonics in
the ice crust
51
(No Transcript)
52
Antarcticas Lake Vida closest analogue to
Europa?
53
Ganymede
  • Farther from Jupiter less tidal heating.
  • But bigger than any other moon in the solar
    system, bigger than Mercury (3200 miles)
  • This helped it retain some heat, and tidal
    heating is still able to make an ice/slush layer
    deep under the surface ice
  • Not believed to be tectonically active now, but
    was in the distant past see these wrinkles?

54
Ganymede globe gray
55
(No Transcript)
56
ganymede
57
(No Transcript)
58
Callisto Last and Farthest of the Galilean Moons
  • Note the ancient surface, which you can tell
    because of the many impact scars.
  • Tidal friction goes as 1/r3, and this far from
    Jupiter (4.5 times farther than Io), Callisto
    experiences only 1 of the tidal heating as Io.
    Not enough to melt ice.

59
Callisto globe
60
(No Transcript)
61
Callisto cratering
62
(No Transcript)
63
Callisto ice spires
64
Jupiter small rocky moons
65
Saturn
  • Slightly smaller than Jupiter, but much less
    massive. Not enough mass (gravity) to compress
    the hydrogen into a thick liquid layer like
    Jupiter
  • So, its mostly a gaseous hydrogen and helium
    atmosphere
  • Most obvious feature very reflective and
    massive rings

66
saturnHST
67
Saturn hst2
68
Saturn rings
69
Cassini division close up
70
Mimas and rings
71
Saturn dragon storm
72
Saturn aurorae
73
Saturn aurorae sequence
74
The Cassini Mission Continues to Explore the
Saturn System
  • Cassini also included a spacecraft called
    Huygens which separated from the main craft and
    parachuted down to the surface of Titan

75
Titan Only Moon in the Solar System with a
Bonifide Atmosphere
  • Not a great atmosphere, though
  • Made of. Smog!
  • Actually, mostly Nitrogen (like Earth), but with
    hydrocarbons making a photochemical smog
    component.
  • Atmospheric pressure is just like Earth!
  • Like a very cold Los Angeles
  • Bummer, Dude!

76
(No Transcript)
77
Titan haze from side
78
Titan color
79
Titan bw oceans
80
Titan shorelines
81
titan
82
Titan oceancanyon
83
Titan impact crater
84
Titan bouldersColor
85
(No Transcript)
86
(No Transcript)
87
(No Transcript)
88
(No Transcript)
89
(No Transcript)
90
Phoebe
91
Enceladus
92
Enceladus surface wedge
93
Enceladus surface
94
Enceladus surface2
95
Enceladus cracks
96
The Death Star Moon Mimas!
97
Mimas
98
Rhea cassini
99
Iapetus The Walnut Moon
100
iapetus
101
One side is Dark Brown
  • This is the side that leads, while it orbits. The
    front side
  • The material is carbonaceous and complex
  • One theory, material knocked from Phoebe, the
    nearest moon?

102
(No Transcript)
103
But the trailing side is covered with Carbon
Dioxide Ice
104
(No Transcript)
105
Hyperion The SpongeBob Moon! (animation)
106
  • Hyperions dark spots are made of hydrocarbons,
    and the white material is mostly water ice, but a
    bit too of CO2 dry ice.
  • The dark hydrocarbons absorb more sunlight and
    heat and sublimate their way down making the
    dimpled surface, is the best current idea of why
    it looks so bizarre

107
Epithemus
108
Uranus
  • About 5 times the diameter of Earth.
  • Mass of 14 Earths
  • Too little mass to create a liquid hydrogen core.
    Hydrogen, Helium interior down to small rocky
    core.
  • Colored Blueish by methane (CH4), which absorbs
    red sunlight.

109
Uranus, rings in ir
110
Uranus,ringsHST
111
Oberon
112
Miranda
113
Miranda hi res
114
Miranda bullseye
115
Miranda cliff
116
Neptune
  • Mass of 17 Earths
  • Structure very similar to Uranus
  • Hydrogen, helium, and methane in the upper
    atmosphere

117
Neptune HST
118
Neptunes Great Dark Spot
119
One Big Moon - Triton
  • Triton orbits Neptune in a very elliptical
    ellipse.
  • It also orbits backwards from Neptunes spin
  • This could not have happened if Triton was formed
    from the same protoplanetary condensation as
    Neptune.
  • Triton must be a former Kuiper Belt Object,
    captured by Neptune

120
(No Transcript)
121
triton
About PowerShow.com