Letters of Intent for 2015

LoI 2015-175
Focus Meeting: Highlights in the Exploration of Small Worlds

Date: 3 August 2015 to 14 August 2015
Location: Honolulu, HI, United States
Contact: Dominique Bockelee-Morvan (dominique.bockelee@obspm.fr)
Coordinating division: Division F Planetary Systems and Bioastronomy
Co-Chairs of SOC: Bockelée-Morvan, Dominique (LESIA, Observatoire de Paris)
Caselli, Paola (University of Leeds)
Hestroffer, D. (IMCCE, Observatoire de Paris)
Chair of LOC: ()



- First results from the Rosetta mission towards comet 67P/Churyumov-Gerasimenko
- First results from the Dawn mission towards dwarf planet Ceres
- First results from the New Horizons mission towards dwarf planet Pluto
- First results from the Gaia mission on small bodies of the Solar System
- Recent physical and chemical investigation of comets, asteroids, dwarf planets, transneptunian objects, and icy and irregular satellites, from Space and Earth (including ALMA, Herschel, NEOWISE, Cassini, EPOXI, large surveys as Pan-STARRS...)
- Comets and Main-Belt comets of the triennium, e.g., C/2012 S1 (ISON), C/2013 A1 (Siding-Spring).
- Highlights in geochemical analyses of extraterrestrial matter
- New evidence for the asteroid-comet continuum
- Primitive Solar System material as tracer of Solar System formation: analogies and differences with star-forming regions and protoplanetary disks
- Future Space and Earth Exploration of Minor Bodies and icy satellites (Osiris-Rex, Hayabusa 2, MarcoPolo-R, JUICE, 2014 NASA Discovery program, ASTER, LSST, ALMA...)



Small bodies of the Solar System are believed to be the remnants - either fragments or “survivors”- of the swarm of planetesimals from which the planets were formed. They are thus primitive leftover building blocks of the Solar System formation process that can offer clues to the chemical mixture from which the planets formed some 4.6 billion years ago. By investigating in detail the physical and chemical properties of asteroids, comets, transneptunian objects and dwarf planets, one can characterize the conditions and processes of the Solar System's earliest epoch. This extends also to some planetary satellites, which share, with small bodies and dwarf planets, similar properties and/or formation history.

2014-2015 promise to be the golden years of the space exploration of these solar system objects. The ESA Rosetta mission will reach comet 67P/Churyumov-Gerasimenko in mid-2014, deposit the lander Philae in November 2014, and remains in the close vicinity of the comet until the end of 2015. After its successful journey around asteroid Vesta in 2011, the Dawn mission of the NASA Discovery Program will rendezvous with dwarf planet Ceres in Spring 2015. In July 2015, the News Horizons NASA mission will flyby and study dwarf planet Pluto and its moons. In addition, whereas the NEOWISE has been revived with the goal of discovering and characterizing quantities of near-Earth objects, the ESA Gaia mission will undertake in 2014-2018 a comprehensive spectroscopic investigation of hundreds of thousands of asteroids and comets. Last but not least, significant progress in the characterization of small Solar System bodies, dwarf planets, icy and irregular planetary satellites is expected from Earth-based large surveys (e.g. Pan-STARRS), observations with large observing facilities (e.g., ALMA, Herschel, HST, and 10-m class optical telescopes), as well as from geochemical analysis of meteorites, micrometeorites, and interplanetary dust particles.

The goal of the proposed focus meeting is to highlight results obtained from the Rosetta, Dawn, New Horizons and Gaia missions, as well as recent achievements obtained from other space facilities, including past space missions, ground-based telescopes, and geochemical analyses. With, in particular, the discovery of Main-Belt comets and the analysis of comet samples collected by the Stardust mission, it has become increasingly evident that the differences between Main-Belt primitive asteroids and comets, are much less sharp than previously thought. Major progress in our understanding of the asteroid-comet continuum is expected in the coming years, both from physical, chemical and dynamical analyses and models of the chaotic early Solar System, and this topic will be a focus of the meeting. Rosetta will provide unprecedented information on the chemical and isotopic properties of the primitive material trapped in cometary nuclei. In parallel, ALMA will unravel the chemistry of protoplanetary disks and star-forming regions, finally allowing a quantitative comparison with the Solar System composition. This meeting will thus be the right time to synthesize analogies and differences between star-forming regions and Solar Nebula material, and better understand our astrochemical history.

In summary, the IAU General Assembly in 2015 is a tremendous opportunity to highlight and spread to a large audience the spectacular results of several space missions towards small bodies and dwarf planets of the Solar System. It is also a tremendous opportunity to address recent progresses made on their physical and chemical properties, their interrelations and their evolutionary paths. The study of planetary formation is an interdisciplinary topic, per nature. The proposed focus meeting will gather researchers of different communities for a better understanding of Solar System formation and evolution.