istituto di astrofisica spaziale e fisica cosmicaistituto di fisica dello spazio interplanetario...

Istituto di Astrofisica Spaziale e Fisica CosmicaIstituto di Fisica dello Spazio Interplanetario

Roma, 15 Dicembre 2003Relatore: Fabrizio Capaccioni

Planetology at IASF/IFSI (1/2)

Investigation methodologies:

Ground Observations: NEO, Comets.

Theoretical approach: numerical modeling, data analysis and interpretation.

Laboratory Activity: Instrument prototypes tests, Verification of in-flight Instrument performances, spectrophotometry of laboratory samples.

Participation to Space Missions with Hardware production.

The planetology group counts about 35 persons including technicians, Art.15, fellowships and temporary contracts.

Since the end of ’80 there has been a strong cooperation between the two groups in IASF and IFSI.



Planetology at IASF/IFSI (2/2) Participation to all ESA planetary missions with leading roles (PIs) or

with qualified participation (Co-Is with H/W production):

In-Flight: Mars Express (PFS, OMEGA-VNIR), Smart-1 (AMIE);

In preparation: Rosetta (VIRTIS), Venus Express (PFS-2, VIRTIS-2)

Future: BepiColombo (Imaging Spectrometer, Camera), Pasteur P/L (Ma-MISS), Space Station (PFS)

Participation to NASA missions, again with a high profile role:

In-Flight: CASSINI (VIMS). 5 of the 6 Italian members of the VIMS Science Team are from IASF/IFSI.

In preparation: DAWN (VIR). PI-ship of the Imaging Spectrometer VIR

Future: JPO (Jupiter Polar Orbiter). Imaging Spectrometer.

Istituto di Astrofisica Spaziale e Fisica Cosmica

Istituto di Fisica dello Spazio Interplanetario


Giant Planets:The Personality of our Solar System

The Giant Planets are the leading characters of the Planetary System.

They account for 99% of the mass of our planetary system and for 99% of the Solar System angular momentum.

Jupiter’s gravitational control of the planetesimal distribution in the inner primordial Solar System has been crucial for the development of Life on Earth.

The Giant planets represent our link to the understanding of the observed extra-solar planetary systems.



Giant planets are the keys to understand the Planetary System

formation Two competing theories have been proposed:

o Gas accretion onto a pre-existing solid core (Safronov, 1969; Coradini and Magni, 1979); core mass ~ 15 Earth Masses, timescale driven by core formation and subsequent accumulation of gas.

Criticality of the timing between gas accretion and onset of T-Tauri phase.

o Direct formation via gravitational instability in the gas (Boss, 2000; Mayer et al. 2002); Growth of Giant planets at same time of central star.

Need to stop migration to inner Solar System. How do we choose?

o Direct Observations: Is a rock-ice core present?

o Numerical Modeling: can the cores accrete their gas envelope fast enough? How does a giant planet interacts with the gas nebula?



Rationale for Nucleated Instability Inner boundary of Giant planets region

Hydration water Water as primary constituent



Modeling Giant Planets evolution at IASF-IFSI

Local personnel: Gianfranco Magni, Angioletta Coradini Collaborations:

o University of Arizona (J. Lunine)

o IAS-CNRS (O. Forni)

o Observatoire Paris-Meudon (D. Gautier)

Hydro-dynamical evolution of protoplanetary disks and of Giant planets in a 3D scheme (Magni and Coradini, PSS in Press).

N-body 3D dynamical interaction of giant planets and a planetesimal swarms. Gas-planetesimal coupling is taken into account by a viscosity term.

Montecarlo code for the simulation of the radiative transfer from a protoplanetary disks (Blois, 2001).

Evolution of protosatellitary disks around giant planets and formation of regular satellites systems (UofA Press 1989).



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Modeling Jupiter formation (1)

3D Evolution of a Jupiter in a 0.02 Msol protoplanetary disk.

The disk is simulated between 2AU and 10AU.

Initial core mass 15 MEarth

Snapshot at 2000 years. The quasi-equilibrium

structure of the growing planet and its interaction with the disk is computed simultaneously with the evolution of the disk itself. PSS in press



Modeling Jupiter formation (2)

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Istituto di Astrofisica Spaziale e Fisica Cosmica

Istituto di Fisica dello Spazio Interplanetario


CASSINI at Saturn



VIMS-IR(USA)

VIMS-Vis(Italy)

VIMS is a Hyperspectral imager working in the spectral range 0.3 - 5.0 m with a spectral resolution of 7.3 nm in the Vis and 16 nm in the IR.

Its FOV is of 64 mrad with a spatial resolution of 167 rad (Vis) and 250 rad (IR)

VIMS Visual and Infrared

Mapping Spectrometer



VIMS-CASSINI at IASF-IFSI Local personnel:

5 Science Team Members 5 Collaborators including temporary contracts

Collaborations: U of A, Un. Hawaii, JPL, IAS-CNES, ObsPM, Un. Of Washington,

NASA-AMES, DLR-Berlin, Un. of Nantes

Scientific Objectives: Titan: Determination of Titan's surface properties, of the vertical distribution of

condensable and chemically active gas species, stratospheric temperature profiles from occultation measurements.

Saturn: 4-dimensional views (i.e., over latitude, longitude, altitude, and time) of Saturn's atmospheric phenomena, vertical distributions of variable gas species, including condensables and disequilibrium species.

Icy Satellites: Determine the surface compositions and in particular the composition of any dark material (organic) on Saturn's satellites, especially Iapetus, Hyperion and Phoebe.



VIMS-Vis Spare Model VIMS-Vis Spare Model is being extensively used in our Clean Room to evaluate the performances of the In-flight model and to monitor and control the instrument behaviour under specific conditions (Alignment tests, Solar port test, On-board calibration subsystem).



Imaging Spectroscopy

Spectral Information

Spatial Information

Surface Mineralogy

Geologic History

Atmospheric Composition

Spatial-Temporal variations



Venus nightside Observation

VIMS saw the surface of Venus for the first time at multiple sub-micron wavelengths, proving that sub-micron spectroscopy of the Venusian surface is possible.

VIMS-VIS provided the first ever observations of the emission from Venus surface at 850 and 900 nm.

Icarus, 2000

Terminator

S/C Motion



Lunar Observation

Ilmenite (Fe and Ti Oxide) is abundant in the Maria while Pyroxene is abundant on the Highlands. The mineralogic map points out that differentiation mechanisms have been taking place on the Moon

VIMS ImageCASSINI Imaging System



VIMS In-flight VIMS In-flight CalibrationCalibration

Icarus, 2003

Using Venus and Lunar data we were able to revise the on ground calibration achieving an absolute radiometric calibration with an accuracy better than ±5%.



Io Spectrum from VIMS

SO2 Frost Absorptions

Thermal emission

SO2 Frost Absorption

Icarus, 2003

istituto di astrofisica spaziale e fisica cosmicaistituto di fisica dello spazio interplanetario...

Documents

growth of giant planets

fabrizio capaccioni

press slide

fabrizio capaccioni

planetary system formation

core formation

saturn slide

inner solar system