Letters of Intent received in 2020

LoI 2022-2126
Complex Planetary Systems II: Latest methods for an interdisciplinary approach

Date: 4 July 2022 to 9 July 2022
Location: Namur, Belgium
Contact: Anne Lemaitre (anne.lemaitre@unamur.be)
Coordinating division: Division A Fundamental Astronomy
Other divisions: Division A Fundamental Astronomy
Chair of SOC: Libert Anne-Sophie (Unamur)
Co-Chairs of LOC: Lemaitre Anne (Unamur)
Füzfa André (outreach) (Unamur)



- Planetary systems
- Complex systems
- Interdisciplinary approach
- Numerical and methodological latest techniques
- Application to exoplanets, disks, natural satellites, small bodies, rotational dynamics, history of planetary systems, cosmology, space debris



The Celestial Mechanics group of the University of Namur (Belgium) was founded in 1970 by Professor J. Henrard, and has followed a regular cycle of 8 years in the organization of international meetings: for the last ones, let us mention the IAU Colloquium 172 "Impact of modern dynamics in astronomy" in 1998, the meeting for the retirement of J. Henrard in 2006 dedicated to the "Rotation of Celestial bodies", and the IAU symposium IAUS 310 "Complex Planetary Systems" in 2014. The next challenge is then scheduled for 2022.

The symposium IAUS310 held in 2014 was a real success: more than 120 astronomers were present. The topic of the meeting was in line with the new research direction of the astronomers of Namur, who decided in 2010 to join the Complex Systems Center (naXys) of the University. The 2014 symposium was untitled "Complex Planetary Systems" to concretize this affiliation.

Complex systems are systems composed of interacting parts/agents whose local behavior, resulting from the interactions between them, cannot provide a complete understanding of the global behavior, i.e. when the system is considered as a whole, on a macroscopic scale. This implies that several levels of description/modeling of the system should be present at the same time, micro-meso-macro. This forces complex systems to be studied by transdisciplinary teams, able to understand the whole construction and critically analyze the connections among the description levels.

Now the center naXys has become a University Research Institute (www.naxys.be), with one of its five research orientations dedicated to SPACE (dynamical astronomy, cosmology and astrobiology); it is presently chaired by an astronomer (Pr. A.-S. Libert) and the fusion of different scientific disciplines, around the Complex systems, has shown its powerful efficiency, as illustrated for instance recently by the precise modelling of the covid-19 pandemic in Belgium by a multidisciplinary naXys team, gathering statisticians, network specialists, dynamicians and cosmologists.

Planetary systems are intrinsically complex. The huge number of available observations (from ground and space) and their accurate precision, as well as the computational power and speed of our present-day computers have spectacularly changed the nature of the dynamical models used in planetary evolution studies. Planetology, celestial mechanics, cosmology, space geodesy have considerably evolved in that direction during the last decade, and have reinforced the need for crossing experiences and methods.

Let us mention several examples: the concept of habitability of an extrasolar planet, the dynamical history of the Solar System and other planetary systems, the rotation of planets and satellites linked to their internal structure, the motion of natural satellites needing astrometry, tides and dissipations, the thermal effects on the evolution of the rotating small asteroids, the long term evolution of space debris and satellites, including drags, shadowing effects, collisional chain reactions. In all these results the formal historical border between analytical and numerical approaches has now disappeared.

Our new symposium is a real opportunity to demonstrate the power of interdisciplinary collaboration after more than ten years of experience. This is a unique occasion to gather astronomers of many disciplines together. The global thematic remains the planetary systems, but firstly, the tools and the methods have CONSIDERABLY EVOLVED in the last years (MCMC, population synthesis, machine learning...), and secondly, INTERDISCIPLINARITY has attracted more communities and has given rise to new scientific fields (e.g. astrobiology).

The presentation and the organization of the meeting will be innovative, with a priority to young bright speakers on interdisciplinary topics, besides round tables, poster show and some prizes encouraging the best presentations. CPS-II will take advantage of CPS-I first experience and realizations, but will open new doors and create collaborations, exchanges of ideas, combinations of techniques, sometimes unexpected, to tackle the complex astronomical systems.

Pr. Anne-Sophie Libert, specialist of exoplanets dynamics, will chair the SOC, helped by an international panel of scientists, representing the main disciplines related to planetary systems, while the LOC and the proceedings edition will be under the responsibility of Pr. Anne Lemaitre, with the help of several local researchers and administration staff. The outreach program will be especially developed, under the responsibility of Pr. André Füzfa, laureate of the (outreach) Wernaers Prize.

The University of Namur is ideal to organize such an event, as proven in the past; the university will offer the lecture halls, the meeting rooms, the technological help, the access to the restaurant, to the student dormitory, all available in this summer period. The city of Namur represents a very nice environment and proposes hotels and restaurants besides an historical citadel.