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, 5-6 novembre 2003Relatore: Maria Teresa Capria

MINOR BODIESMINOR BODIESBack in time to the Origin of Solar SystemBack in time to the Origin of Solar System



Why do we study Why do we study cometscometsCometary material has been submitted to

the lowest level of processing: it contains information on the physical and chemical processings prevailing during the early stages of the Solar System

Comets probably played an important role in the evolution of Earth, bringing water and organic matter

Physical and chemical processes taking place in the coma are still poorly understood

We have only few images of the a nucleus surface

The interior of the nucleus is completely unknown

And then we have now Kuiper Belt Objects completing the inventory of Solar System bodies…



Why do we study asteroidsWhy do we study asteroids

There are surprising differences between them:

Asteroids range from small rocky fragments to big differentiated bodies like 4 Vesta; they can be binary and can have satellites…

There is a continuous change in composition going from the inner to the outer Solar System.

We have samples of their matter (meteorites), but the link between some types of meteorites and the bodies from which they originated (parent body) is not clear.



How do we study minor bodiesHow do we study minor bodies

From all the points of view…

Theoretical Observational Space mission participation

Comet nucleus modelingStatistical analysis (classification)

Mineralogical characterization of asteroids through near infrared spectroscopyComa composition through high resolution spectroscopy in the visible range Rosetta to comet

67P/Churyumov-Gerasimenko…DAWN to 4 Vesta …



Theoretical models of the thermal evolution and differentiation of a nucleus must be used to link coma observations with real nuclei characteristics and properties. At the IASF a nucleus model has been developed; many real comets have been simulated, as well as Kuiper Belt Objects.We participated in an international team, located at ISSI in Bern, that defined a standard model.Our model is also used as a help in the planning of the instrument operations of VIRTIS, our imaging spectrometer on Rosetta mission.

The theoretical point of view: nucleus The theoretical point of view: nucleus modelingmodeling



Space missions: theSpace missions: the Rosetta journeyRosetta journeyThe ESA cornerstone mission Rosetta is set to a rendezvous with Comet 67P/Churyumov-Gerasimenko, orbiting around it and making observations as it journeys towards the Sun. A lander will be deposited on the surface of the comet.The mission is aimed to study the origin of comets, the relationship between cometary and interstellar material and its implications with regard to the origin of the Solar System. It carries instruments for remote sensing, composition analysis, nucleus large-scale structure, dust flux and mass distribution, comet plasma environment and solar wind interaction, radio science.

Launch date: 26 Feb 2004Perihelion passage: 2015



VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) combines a double capability: moderate-resolution visible and infrared imaging in the 0.25-5 m range (VIRTIS-M channel) high-resolution spectroscopy in the 2-5 m range (VIRTIS-H channel).VIRTIS maps and studies the nature of the solids and the temperature on the surface of the nucleus. Also identifies comet gases, characterises the physical conditions of the coma and helps to identify the best landing sites.

Radiator

Baseplate (S/C Interface)

VIRTIS-HVIRTIS-M

Cold box

VIRTIS on ROSETTAVIRTIS on ROSETTA



INAF IASF, IFSI Padua, Lecce and

Perugia Universities Capodimonte and

Arcetri Observatories

VIRTIS on ROSETTAVIRTIS on ROSETTA

Spectral resolutionSpectral sampling

100-380 70-360 1300-3000 1.89nm 9.44nm 0.6nm

-M visible –M IR -H

VIRTIS international consortium

The instrument has been successfully integrated and tested and is ready for the launch

P.I. Angioletta Coradini

Paris-Meudon Observatory

IAS, Orsay

DLR Berlin Galileo Avionics, Florence (prime contractor)

TecnoSystem, NeaplesLaben, MilanKayser Trade, Munich



La missione Dawn: •cos’e’ •Scienza

Space missions: theSpace missions: the DAWN journeyDAWN journey

The NASA Discovery mission DAWN will be launched in 2006 and will orbit Vesta for one year, in 2010; it brings a framing camera, a mapping spectrometer and a gamma ray/neutron spectrometer. The spectrometer is VIR, a re-build (a twin) of the mapper channel of VIRTIS. VIRTIS-M

VIR

A. Coradini is mission Co.I. and instrument P.I.



Vesta is:one of only four bodies for which we have samples (HED meteorites).perhaps the only surviving member of the class of planetesimals that accreted to form the terrestrial planets.Vesta…differentiated 4.5 billion years ago under conditions distinct from Earth, Moon, Marshas a heterogeneous surface of various crustal rocks and possibly excavated mantle rocks.

Why Vesta?Why Vesta?

Thin section of HED meteorite

On Vesta we could:better constrain planet formation by understanding their protoplanetary building blocks test our ideas about the thermal, physical, chemical and mineralogical evolution of planetesimals, presently crafted from the incompletely sampled rubble of disrupted asteroids (meteorites)

Vesta, Space Telescope

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

Documents

rosetta slide

nucleus modeling slide

origin of solar system

virtis maps

vesta slide

maria teresa capria

rosetta mission

munich slide