Evdokimova N., Korablev O., Marchenkov K., Rodin A., Malova H., Podzolko M., Zelenyi L. Space...
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Evdokimova N., Korablev O., Marchenkov K., Rodin A., Malova H., Podzolko M., Zelenyi L. Space Research Institute(IKI), Moscow, Russia All images credit:
Evdokimova N., Korablev O., Marchenkov K., Rodin A., Malova H.,
Podzolko M., Zelenyi L. Space Research Institute(IKI), Moscow,
Russia All images credit: NASA / JPL / Brown University
Galilean Satellites of Jupiter Jupiter has ~50 satellites!
1:2:4 Laplace resonance Ganymede Europa Callisto
http://physics.fortlewis.edu/Astron omy MGS view. Image credit:
NASA / JPL Four Galilean satellites since 1610 Io
http://physics.fortlewis.edu/Astronomy
Slide 4
Activity of Galilean satellites GanymedeEuropaCallistoIo
Adapted from Bagenal et al., 2004 Tidal Energy Impact cratering
Tectonism Magmatism Distance from Jupiter. Proportions are not
kept
Slide 5
Ganymede: General information Diameter: D(Gan) = 5262,4 km ~
1.5D(Moon) ~ 1.08D(Mercury) - the largest (not the heaviest!)
satellite of Solar System; Mass: M(Gan) ~1.48*10 23 kg ~ 2M(Moon)
Density: (Gan) ~ 1800-1900 kg/m 3 Orbital parameters: Orbital
period: T(Gan) = 7.1546 T(Earth) ~ 7.1546 days Semi-major axis: a =
1 070 412 km Eccentricity: e = 0.0011 (range: 0.0009 0.0022)
Inclination: i = 0,204 (range: 0,05 0.32) Image credit: NASA /
JPL
Slide 6
Breakthrough missions having explored Ganymede 1977 launch
Voyager -1 and -2 1989-2003 Galileo mission. 1996-1997 the best
observation of Ganymde 2006 launch New Horizons. Now it is going to
Pluto. 2007 - Ganymede flyby
Slide 7
Galileo mission (1989-2003) 18 Oct 1989 Launch (16:53:40 UT) 10
Feb 1990 Venus Flyby 8 Dec 1990 First Earth Flyby 29 Oct 1991
Asteroid Gaspra Flyby 8 Dec 1992 Earth Flyby 2 28 Aug 1993 Asteroid
Ida Flyby Jul 1994 Comet Shoemaker-Levy 9 Impact Observations 13
Jul 1995 Probe Release 7 Dec 1995 Probe Descent (22:04 UT - 23:02
UT) 8 Dec 1995 Jupiter Orbit Insertion (00:27 UT) 6 Sep 1996
Ganymede Encounter 2 4 Nov 1996 Callisto Flyby 3 19 Dec 1996 Europa
Flyby 4 20 Feb 1997 Europa Flyby 6 5 Apr 1997 Ganymede Flyby 7 10
Feb 1998 Europa Flyby 13 25 May 2001 Callisto Flyby 6 Aug 2001 Io
Flyby 31 16 Oct 2001 Io Flyby 32 17 Jan 2002 Io Flyby 33 5 Nov 2002
Amalthea Flyby 31 Mar 2003 Jupiter Observations Complete 21 Sep
2003 Jupiter Impact (18:57:18 UT) Date: 3 Aug 1989 Image credit:
NASA / JPL Date: 18 Oct 1989
Slide 8
Galileo mission (1989-2003) 18 Oct 1989 Launch (16:53:40 UT) 10
Feb 1990 Venus Flyby 8 Dec 1990 First Earth Flyby 29 Oct 1991
Asteroid Gaspra Flyby 8 Dec 1992 Earth Flyby 2 28 Aug 1993 Asteroid
Ida Flyby Jul 1994 Comet Shoemaker-Levy 9 Impact Observations 13
Jul 1995 Probe Release 7 Dec 1995 Probe Descent (22:04 UT - 23:02
UT) 8 Dec 1995 Jupiter Orbit Insertion (00:27 UT) 6 Sep 1996
Ganymede Encounter 2 4 Nov 1996 Callisto Flyby 3 19 Dec 1996 Europa
Flyby 4 20 Feb 1997 Europa Flyby 6 5 Apr 1997 Ganymede Flyby 7 10
Feb 1998 Europa Flyby 13 25 May 2001 Callisto Flyby 6 Aug 2001 Io
Flyby 31 16 Oct 2001 Io Flyby 32 17 Jan 2002 Io Flyby 33 5 Nov 2002
Amalthea Flyby 31 Mar 2003 Jupiter Observations Complete 21 Sep
2003 Jupiter Impact (18:57:18 UT) Date: 3 Aug 1989 Image credit:
NASA / JPL Date: 18 Oct 1989
Slide 9
Spacecraft instruments: Solid State Imaging Camera (SSI) Near
Infrared Mapping Spectrometer (NIMS) Photopolarimeter-Radiometer
(PPR) UltraViolet Spectrometer (UVS) Magnetometer Energetic
particles detector Plasma wave spectrometer Dust detector Heavy ion
counter Galileos look at Ganymede (1996-1997) Atmospheric probe:
Helium abundance detector Atmospheric structure instrument Neutral
mass spectrometer Nephelometer Net flux radiometer Lightning and
radio emission detector the highest spatial resolution ( ~12 m/px);
the closest flyby ( ~264 km to surface) Galileo mission
(1989-2003)
Slide 10
Ganymede: previous results 1.Internal structure 2.Geology,
surface morphology 3.Atmosphere, exosphere 4.Magnetosphere Gravity
field measurements (Galileo) Magnetic field measurements, energetic
particles(Galileo), aurorae(HST) Surface features analysis(from
images: Voyager, Galileo), mineral composition (from spectroscopy,
Earth-based radar) Measurement types Problem UV spectroscopic
measurments, Voyager-1, HST, Galileo
Slide 11
Strongly differentiated internal structure: 1) Liquid core :
Fe, (+FeS?), R~400-1300 km 2) Rock mantle(silicates, Mg-rich?) 3)
Ice mantle (liquid-solid: high-pressure phase), 800-950 km 4) Ice
crust (130-150km) (more lighter) Ice phase state and lattice type
are unknown Ice near its melting becomes a low-viscosity solid
=> => Ice mantle convection like Earth rock mantle? rocks
~60%, ices~40% (if ~1,94 g/cm Pioneer, Voyager) 1. Internal
structure 1 2 3 4
Slide 12
Crust deformations: tides Callisto tidal flexing < Ganymede
tidal flexing < Europe tidal flexing Tides from interior model
of Ganymede: In the presence of a liquid ocean: tide can exceed 7 m
peak-to-peak variation Without an ocean: tidal amplitudes are less
than 0.5 m ( Moore, 2003) Mass anomalies 2 surface mass anomalies?
one a positive mass at high latitude and the other - a negative
mass at low latitude. No obvious geological features that can be
identified with the anomalies. (Galileo data, Anderson 2004) 1.
Internal structure
Slide 13
Open questions Interiors structure Existence of liquid mantle
Origins of mass anomalies Ice structure and form Role of tidal
heating at present and in the past Etc 1. Internal structure
Possible solutions and related payload -Seismometer -Thermal
mapping -Gravity field mesurements -Librations measurements (e.g.
by stellar sensor) -Etc?
Slide 14
Numerous traces of active geological processes in early
history: tectonism, volcanism (caldera-like features- Spaun,2001;
cryovolcanism Schenk, 2001), etc Numerous impact craters 2
different types of surface: 2. Geology, surface morphology Galileo,
140m/px *both types may be reticulate 2 - Bright terrain(2) ~ 2/3
of Ganymede The youngest; less cratered; lanes through dark terrain
1 - Dark terrain ~ 1/3 of Ganymede The oldest (~4Gy); heavily
cratered; palimpsets; Callisto-like
Slide 15
Numerous traces of active geological processes in early
history: tectonism, volcanism (caldera-like features- Spaun,2001;
cryovolcanism Schenk, 2001), etc Numerous impact craters 2
different types of surface: 2. Geology, surface morphology Galileo,
140m/px *both types may be reticulate DEM of topography (same
scene) Schenk, 2001
Slide 16
Global map based only on low resolution images Galileo/Voyadger
data 2. Geology, surface morphology
Slide 17
Geological units Morphology map based on Galileo mosaic
Prockter, 1998
Slide 18
Surfical rocks chemical composition (telescopic observations;
Galileo/NIMS spectroscopic data: T.McCord, 1998, etc) - mainly H 2
O ice (50-90%) - presence of CO 2 ice (Hibbits, 2003) - signs of SO
2, NH 3 - hydrated minerals (MgSO 4 nH 2 O, Na 2 Mg(SO 4 ) 2 4H 2
O,...? - still under studies - unknown spectral features *adsorb.
bands 3.7, 3.88, 4.05, 4.25 m, etc - unknown materal: *darker and
redder then water ice: carbon-rich meteorite/mix of clays/organics
component? tholin? - still under studies 2. Geology, surface
morphology
Slide 19
Surfical rocks chemical composition (telescopic observations;
Galileo/NIMS spectroscopic data: T.McCord, 1998, etc) - mainly H 2
O ice (50-90%) - presence of CO 2 ice (Hibbits, 2003), O 2 - signs
of SO 2, NH 3 - hydrated minerals (MgSO 4 nH 2 O, Na 2 Mg(SO 4 ) 2
4H 2 O,...? - still under studies - unknown spectral features
*adsorb. bands 3.7, 3.88, 4.05, 4.25 m, etc - unknown materal:
*darker and redder then water ice: carbon-rich meteorite/mix of
clays/organics component? tholin? - still under studies Carlson et
al., 1996.. NIMS/Galileo mapping 2. Geology, surface
morphology
Slide 20
Surface temperature distribution (PPR/Galileo data) Need for
further studies of surfical thermophysical properties! Night side
Heat radiation ~ 60 m Tmin=80 K (observed) Day side 2. Geology,
surface morphology
Slide 21
Open questions Searching for specific substances: -non-organic
components: sulfates, hydrated minerals -organics: tholin, etc;
Altimetry and geologic mapping; Thermal inertia data; (Water) ice
microstructure; Geological processes: current and past Confirmation
of cryovolcanism hypotheses Age of dark and light terrains Vertical
structure of crust beneath dark terrain . etc 2. Geology, surface
morphology Possible solutions and related payload Elemental
analysis: -Laser-stimulated emission UV spectroscopy
-Laser-stimulated mass spectroscopy Analysis of species: -IR
imaging spectroscopy -GCMS -Raman spectroscopy -DLS spectroscopy
Mineralogical & morphological analysis: -Multispectral camera
-IR imaging spectroscopy -Microscope etc?
Slide 22
-Very tenuous one: ~10 16 cm -2 O, O 2, H, H 2, H 2 O, OH, ?
sublimation and sputtering from icy surface ? -Frozen and trapped
gases in the Ganymede surface? -Micron-sized dust halo loosely
bound by gravity ice grains, the result of meteorite impacts 3.
Atmosphere. Exosphere Ganymede does have atmosphere!
Slide 23
Results of Dust detector/Galileo 3. Atmosphere. Exosphere
Kruger, 2000
Slide 24
Open questions Abundance of volatiles, isotopes Sources/sinks,
interactions with the surface and interiors Exosphere, escape
mechanisms Photochemistry Interactions with Jovian magnetosphere
Thermal and non-thermal heating, kinetics, dynamics (tides?) Dust
particles acceleration and escape 3. Atmosphere. Exosphere Possible
solutions and related payload Mass-spectrometry Radio occultations
between the orbiter and lander Microwave sounding from the orbiter
IR heterodyne sounding from the orbiter or lander
Slide 25
4. Magnetosphere
Slide 26
Ganymedes magnetic field = internal +induced magnetic fields
The origin of internal m.f. is the dynamo mechanism due to
convection of core forming liquid materials in Ganymedes core (Fe-
FeS ) Hauck et al., JGR, 2006 Induced magnetic field is due to time
varying component of the externally imposed Jupiters magnetic
field. Source: electrical conductivity of a liquid water layer
bearing electrolytes such as salts and acids. Kivelson et al.,
Icarus, 2002 Magnetic moment M=1,310 13 3 ~ three times greater
than Mercurys magnetic moment M L~4-5 RG ~10000-13000 km Ganymede
is surrounded by a corona of hot oxygen atomes Eviator et al., PSS,
2001 Region of unstably trapped plasma particles; convection
region. Kivelson et al., JGR, 1998 Ganymedes magnetic field at
equator ~ 720 nT Jupiters magnetic field ~120 nT Induced magnetic
field ~ 60 nT
Slide 27
Ganymedes interaction with the Jupiterian magnetosphere
Ganymedes magnetosphere From presentation by D.Titov 4.
Magnetosphere
Slide 28
Regions of high-energy ions+electrons E~100 keV Interaction
with Jupiters magnetic field No bow shock: velocity of
magnetospheric flow is sub- sonic Kivelson et al., 2001 Ultraviolet
auroral brightness (Eviator et al., 2001) Ionosphere Open field
lines are connected to Jupiters polar magnetic field. Field-aligned
currents in Alfven wings ~ 1.2*106A Jia et al., JGR, 2009 Upstream
Reconnection line Downstream reconnection line Plasma flows.
Magnetsopheric convection. Z X Alfven wings Asymmetrical
Magnetopause
Slide 29
Charged particle flux and radiation dose equatorial profiles at
Jupiter Equatorial profiles of radiation doses under 0.27, 1, 2.2
and 5 g/cm 2 shielding, and separately dose under 2.2 g/cm 2 from
protons only near Jupiter.
GanymedeIoAmaltheaEuropaGanymedeIoAmaltheaEuropa Equatorial
profiles of the integral fluxes of E > 0.5, >2 and >10 MeV
electrons and E > 2, >10 and >30 MeV protons at
Jupiter.
Slide 30
Open questions: Sources of internal and induced magnetic fields
Plasma convection and transfer in Ganymedes magnetosphere Structure
of the ionospheric current system Particle acceleration mechanisms
Dynamics of heavy ions in polar and equatorial regions; their role
in auroral brightness in Ganymede Influence of Ganymede to Jupiters
auroras 4. Magnetosphere
Slide 31
Conclusions Ganymede is exceptionally challenging target for
Russian and international space exploration program Lots of hot
topics to remain hot for the next 15(?) years Strong,
multidisciplinary community is needed