Chondritic meteorites constitute the most ancient rock record available in the laboratory to study the formation of the solar system and its planets. Detailed investigations of their mineralogy, petrography, chemistry and isotopic composition and comparison with other primitive solar system samples such as cometary dust particles have allowed through the years to decipher the conditions of formation of their individual components thought to have once been free-floating pieces of dust and rocks in the early solar nebula. When put in the context of astrophysical models of young stellar objects, chondritic meteorites and cometary dust bring essential insights on the astrophysical conditions prevailing in the very first stages of the solar system. Several exemples are shown in this chapter, which include (1) high temperature processes and the formation of chondrules and refractory inclusions, (2) oxygen isotopes and their bearing on photochemistry and large scale geochemical reservoirs in the nebula, (3) organosynthesis and cold cloud chemistry recorded by organic matter and hydrogen isotopes, (4) irradiation of solids by flares from the young Sun and finally (5) large scale transport and mixing of material evidenced in chondritic interplanetary dust particles and samples returned from comet Wild2 by the Stardust mission.

Establishing the origin of short-lived radionuclides (SLRs) with half-lives ≤100 Myr has important implications for the astrophysical context of our Sun's birth place. We review here the different origins proposed for the variety of SLRs present in the solar accretion disk 4.57 Ga ago. Special emphasis is given to an enhanced Galactic background origin for 60Fe which was inherited from several supernovae belonging to previous episodes of star formation, rather than from a nearby, contemporaneous supernova.

Comets are made of ices, organics and minerals that record the chemistry of the outer regions of the primitive solar nebula where they agglomerated 4.6 Gyr ago. Compositional analyses of comets can provide important clues on the chemical and physical processes that occurred in the early phases of Solar System formation, and possibly in the natal molecular cloud that predated the formation of the solar nebula. This paper presents a short review of our present knowledge of the composition of comets, focussing on volatiles. Implications for the origin of cometary materials are discussed.

Trans-neptunian objects (TNOs) are believed to be pristine remnants of planets formation, providing constrains on the early stages of the solar system evolution. The knowledge of this population composition and dynamics provides constrains on the formation processes of the early solar nebula, as well as formation processes of other planetary systems around young stars. Nonetheless, because of their great heliocentric distance, and their resulting faintness, all studies are very challenging. 
More than a thousand objects have been detected though, and orbits have been determined for most of them. The resulting dynamical structure is complex and not fully understood: we divide the trans-neptunian region into the Kuiper Belt –itself divided into resonant objects and the classical belt–, the scattered disk and detached objects. 
TNOs physical properties remain poorly known, but we can get constrains on their size, shape, mass, albedo, density or color using different observational methods. Composition is the most difficult property to access though. Only few spectra are available, and they show nevertheless features due to the presence of diverses ices. All those properties result from the competition of several processes that will be discussed. 
The more we learn about TNOs, the more the picture seems complicated. Ultimately, extremely large telescopes, new satellites such as Herschel and space missions like New Horizons will be of great help, since a better understanding of their properties and evolution is critical to improve solar and extra-solar systems formation models.

Here, gravitational scattering of planetesimals (viscous stirring and dynamical friction) and their growth through pairwise collisions (runaway/oligarchic growth) are explained in detail. The masses of accreted protoplanets depend on initial disk surface density and semimajor axis. When the mass of a protoplanet becomes larger than a critical value that is a few to ten earth masses, runaway gas accretion from the disk onto the planet starts. The dependence of the protoplanet masses is responsible for the diversity of extrasolar planetary systems, although orbital migrations of planets are also important drivers to produce the diversity.

Giant planets are by definition mainly made of hydrogen and helium but their precise composition is crucial to understand the processes that led to their formation, and to constrain the origins of the Solar System. Interestingly, all giant planets in the Solar System are enriched in heavy elements compared to the Sun. This is true of the planets as a whole, of their envelopes (i.e. when removing their central core) and of their atmospheres as well. It is now becoming possible to constrain the global composition of transiting extrasolar planets too, with three major results: (i) Planets above the mass of Saturn appear indeed to be mainly made of hydrogen and helium, as expected; (ii) Surprisingly, some planets were able to collect large masses (> 50 M⊕) of heavy elements; (iii) There is a correlation between the mass of heavy elements in a given giant planet and the metallicity of its parent star. These results and others points towards accretion being the dominant mode of formation of giant planets. However there is presently no unique process or ensemble of processes that account for the observed compositions of giant planets.

The existence of an outer belt of small bodies in the Solar System has been inferred for long. Since the first direct observation of a Kuiper Belt Object in 1992, an intensive observational and modeling effort has been made to understand the origin and evolution of the Kuiper Belt. A wealth of information is hidden in both its dynamical structure and size distribution, that we begin to unveil thanks to a complementary approach of numerical simulation and observational surveys. We review below the main structures and physical properties of the Kuiper Belt and the implications for what concern the evolution of the Solar System, after the depletion of the Solar Nebula. The Kuiper Belt can be also considered as the post-planetary disk of the Solar System, so its study helps also to better understand debris disk observed around stars our galaxy.

We study the effect of a perturber on the energy and angular momentum of a test particle on a highly eccentric orbit. We find that both the energy and angular momentum of the test particle are adiabatic invariants when the perturber is on a circular orbit with radius much smaller than the periaps of the test particle. We derive analytical expression for the energy change, or kick, of the test particle with every periaps passage. Using this kick function we formulate mapping for the highly eccentric test particle. We also analyze the stability of resonances and find conditions for asymmetric libration to occur. The resonance widths for highly eccentric orbits are calculated and the criterion for the onset of global chaos is determined.

The available results of deep imaging searches for planetary companions around nearby stars provide us useful constraints on the frequencies of giant planets in very wide orbits. Here we present some preliminary results of the Monte Carlo simulation which compare the published detection limits with the generated planetary masses and orbital parameters. This allow us to consider the impications of the null detection, which comes from the direct imaging techniques, on the distributions of mass and semimajor axis derived from the results of the other search techniques and also to check the agreement of the observations with the available planetary formation models.

The formation of resonant planets pairs in exoplanetary systems involves planetary migration inside the protoplanetary disc: an inwards migrating outer planet captures in Mean Motion Resonance an inner planet. During the migration of the resonant pair of planets, the eccentricities are expected to rise excessively, if no damping mechanism is applied on the inner planet. We express the required damping action to match the observations, and we show that the inner disk can play this role. This result applies for instance to the system GJ 876: we reproduce the observed orbital elements through a fully hydrodynamical simulation of the evolution of the resonant planets.

In the context of the core instability model and of the oligarchic growth of solid protoplanets, we present a set of full evolutionary calculations of in situ giant planet formation. The growth of the core and the planetesimal accretion rate were coupled in a self–consistent way to the envelope's evolution. Several simulations for the formation of a Jupiter–like object were performed taking into account various surface densities for the protoplanetary disc and different sizes for the accreted planetesimals.

We briefly summarise our ongoing efforts to evaluate the success of cometary particle capture by NASA's Stardust mission. We demonstrate the use of a variety of analysis techniques to investigate the state of preservation in laboratory analogues of the Stardust encounter at 6.1 km s-1, using well characterised projectiles and flight grade foils and aerogel.

We have investigated the evolution of a pair of interacting planets embedded in a gaseous disc considering a possibility of the resonant capture of a Super-Earth by an inward-migrating Jupiter mass gas giant. It has been found that the terrestrial planet is scattered from the disc or the gas giant captures the Super-Earth into an interior 3:2 or 4:3 mean motion resonance and the stability of such configuration depends on the initial planet positions and eccentricity evolution. The behaviour of the resulting resonant system has been studied numerically by means of the full 2D hydrodynamical simulations. The results are particularly interesting in light of the recent exoplanet discoveries and provide predictions of what will become observationally testable in the near future.

Dawn space mission will provide the first, detailed data of two of the major bodies in the Main Belt, Vesta and Ceres, and will allow us to study in depth the crater record on the surface of these asteroids and get an insight on their place in the context of Solar System history. In the framework of our studies on the origin of Solar System, we modelled the accretion of Jupiter and, through an N-Body code developed on purpose, we evaluated the flux of impactors on Vesta and Ceres keeping track of their formation zones. We also studied the effects of the possible inward migration of Jupiter on the rate and the characteristics of the impacts. We here describe the different scenarios and their implications for the evolution of Solar System to provide a reference frame for future studies of Vesta's and Ceres' cratering histories.

The characteristics of irradiated solar system planetary atmospheres have been studied for decades. Modern planetary science benefits from an exhaustive body of ground- and space-based data. The study of extrasolar planetary atmospheres, by contrast, is in its infancy and currently rests on a few score of datapoints, mostly of the transiting planets. As the study of exoplanetary atmospheres blossoms, it is well worth remembering lessons learned from the solar system. In this contribution, based on my Les Houches lecture on exoplanet atmospheres, I briefly review a few of the key concepts relevant to understanding planetary atmospheres and point to examples both in our own solar system and among the exoplanets. This short survey aims not to review the field but rather stresses the importance of understanding the structure, dynamics, cloud processes and photochemistry of planetary atmospheres and points the reader towards useful reference works. Here I particularly explain the importance of cloud and photochemical processes in controlling the spectra and albedos of extrasolar planets and urge that care be taken in the interpretation of exoplanet colors.

Atomic hydrogen escaping from the extrasolar giant planet HD 209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. In fact, the upper atmosphere of this planet is evaporating. Observational evidences and interpretations coming from various models are reviewed. Implications for exoplanetology are discussed.

Planet–star plasma interactions can be described as the interaction of a plasma flow with an obstacle, each being possibly magnetized. Examples of the 4 possible situations are found in our solar system, with intense radio emissions produced in 3 cases out of 4, when either the flow or the obstacle is strongly magnetized. Scaling laws are derived that relate the emitted radio power to the power dissipated in the various corresponding flow–obstacle interactions. They are generalized as a “radio–magnetic” scaling law between the output radio power and the magnetic energy flux convected onto the obstacle. Extrapolating it to the case of exoplanets, we find that hot Jupiters may produce very intense radio emissions due to planetary magnetospheric interaction with a strong stellar wind, reconnection between planetary and stellar magnetic fields, or unipolar interaction between the planet and a magnetic star (or strongly magnetized regions of the stellar surface). Emitted radio power is expected in the hecto–decameter range with intensity 103 to 106 times that of Jupiter (unless some “saturation” mechanism occurs). Corresponding flux densities should be detectable at tens of parsecs range with modern radio arrays. We briefly discuss ongoing observational searches as well as the interests of direct radio detection.

Photolysis of methane in Titan's stratosphere is the starting point of gas phase carbon chemistry. Quantitative studies of methane photolytic products are of utmost importance for Titan atmosphere models. With this aim, two experimental strategies are presented in this article. Preliminary results demonstrate the possibility of using CRDS absorption coupled with pulsed photolysis on the example of a halogenated derivative of methane: Trichloromethane (CHCl3).

A hybrid code has been used for three-dimensional simulations of the stellar wind interaction with the ionosphere of an Earth-sized close-in extrasolar planet. The hybrid code treats electrons as a massless, charge-neutralizing, adiabatic fluid while ions are treated as macroparticles. To study the effects of an expanding ionosphere, a consequence of an expanding atmosphere as for e.g. exoplanet HD 209458 b, we have compared the simulation results for an ordinary stationary ionosphere with the results for an expanding ionosphere. In both cases we can identify bow shock, magnetopause and ion-composition boundary. The expanding ionosphere pushes the bow shock and magnetopause upstream and increases the size of the entire interaction region, creating a large wake behind the planet dominated only by the expanding ionosphere.

The evolution of matter in the cosmos includes the production of elements which, over time, produces carbon and other heavy elements needed to form planets and life. The overall physics of the process and the environments in stars where carbon, nitrogen, and oxygen are formed are generally fairly well understood. It is carbon's particular properties of chemical bonding along with its high abundance that make it especially suited as the foundation for life. Over 120 organic molecules are found in interstellar space, and organic phases – some with slight enrichment of one “chiral-enantiomeric” form over the other – are known in meteorites. Delivery of this material to the Earth during formation of the planets was aided by the early presence of Jupiter, whose gravity ensured mixing of materially radially throughout the solar system. In the outer solar system, organic-rich worlds are present and chemistry is evolving there today – Titan is a particularly promising example in this regard. For life as we know it, liquid water is required (though forms of non-Earth life might exist in other liquids), and hence the inferred liquid water environments in Jupiter's moon Europa and Saturn's moon Enceladus are of keen interest along with environments on and within Titan that contain aqueous and non-aqueous liquids.