Planetary collisions are integral mechanisms that both shape the final configuration of the solar system and modify planetary surfaces thereafter. This session is aimed at understanding planetary impact processes at all scales, from the cratering regime to the giant impact regime, in terms of shock processes, dynamical aspects, geochemical consequences, and cratering chronology. We also welcome the examination of competing hypotheses for the giant impact formation of terrestrial and outer solar system bodies. Naturally, advancing our understanding of impact phenomena requires a multidisciplinary approach, which includes (but it is not limited to) numerical modelling, laboratory-scale experiments, geologic and structural mapping, remote sensing, petrographic analysis of impact products, and isotopic and elemental geochemistry analysis. We welcome presentations across this broad range of study and particularly encourage work that bridges the gap between the investigative methods employed in studying planetary impact processes at all scales.

Space missions have provided a wealth of data on the atmospheres and aeronomy of rocky planets and moons, from the lower layers up to the external envelopes in direct contact with the solar wind. A recent emerging finding is evidence that the atmosphere behaves as a single coherent system with complex coupling between layers.

This session solicits contributions that investigate processes at work (chemistry, energetics, dynamics, electricity, escape etc...) on Venus, Mars, and Titan and includes studies of the coupling between the lower/middle and upper atmospheres. Contributions based on analysis of recent spacecraft and ground-based observations, comparative planetology studies, numerical modelling and relevant laboratory investigations are particularly welcome. The session will consist of invited and contributed oral talks as well as posters.

Space missions, ground-based observations and theory allow for detailed characterization of planetary upper atmospheres in the solar system that provides novel insights into the physical mechanisms at play. At the same time, the detection of short-period extrasolar planets has inspired numerous studies of chemistry, dynamics, and escape of the upper atmospheres of these planets, at more extreme conditions than those found in the solar system. More than ever, it is critical to foster the communication between the communities working on the theoretical and observational aspects of both solar system and exoplanet upper atmospheres. This communication will secure a solid progress in the interpretation of new atmospheric observables and in the implications for e.g. planet demographics.

This session brings together researchers from the solar system and exoplanet communities in an attempt to exchange knowledge and ideas. We welcome papers on all aspects of planetary aeronomy i.e., the science of the upper atmosphere, either in the solar system or exoplanet systems. Suitable papers include results on photochemistry and ionization, magnetosphere-ionosphere coupling, energy balance and circulation, atmospheric escape and evolution as well as new observations and novel observational techniques.

Atmospheric aerosols and cloud particles are found in every atmosphere of the solar system, as well as, in exoplanets. Depending on their size, shape, chemical composition, latent heat, and distribution, their effect on the radiation budget varies drastically and is difficult to predict. When organic, aerosols also carry a strong prebiotic interest reinforced by the presence of heavy atoms such as nitrogen, oxygen or sulfur.

The aim of the session is to gather presentations on these complex objects for both terrestrial and giant planet atmospheres, including the special cases of Titan’s and Pluto's hazy atmospheres. All research aspects from their production and evolution processes, their observation/detection, to their fate and atmospheric impact are welcomed, including laboratory investigations and modeling.

Ionospheres are an integral part of planetary atmospheres, being tightly coupled to the neutral atmosphere, exosphere and surrounding plasma environments. Specifically, the ionospheres of unmagnetized (or weakly-magnetized) bodies with substantial atmospheres are controlled not only by solar radiation and neutral atmosphere variations, but also directly impacted by the surrounding plasma environment (e.g. the solar wind for Mars, Venus, Pluto and comets, and the Kronian magnetosphere for Titan) and space weather variability. Understanding how each unmagnetized body reacts to all these factors is a key in comparative aeronomy because although a priori all of them have a general similar behavior, they also have scientifically important differences caused by their different natures. This session focuses on the ionospheres of Mars, Venus, Pluto, Titan, and comets such as 67P/CG, and solicits abstracts concerning remote and in situ data analysis, modeling studies, instrumentation and mission concepts. Topics may include, but are not limited to, day and night side ionospheric variability, sources and influences of ionization, ion-neutral coupling, current systems, comparative ionospheric studies, and solar wind-ionosphere interactions and responses of the ionized and neutral regimes to transient space weather events. Abstracts on general plasma and escape processes are also welcome.

A planetary magnetosphere, formed by the interaction of the solar wind with a planet’s global magnetic field (intrinsic) or upper atmosphere (induced), plays a significant role in both the neutral and ionized regimes of the local space environment. The structure and dynamics of the Terrestrial magnetospheres have many similarities and differences. Mercury and Earth offer examples of intrinsic magnetospheres that experience different degrees of solar wind forcing and atmospheric contributions. The induced magnetospheres of Venus and Mars depict the solar wind-atmospheric interaction with differences in ionospheric densities and the existence of remnant crustal magnetic fields, for instance. Similar plasma processes exist among these magnetospheres, but offer drastically different temporal and spatial scales (e.g., magnetic reconnection, ion escape, wave-particle interaction, flux rope formation). To provide a forum for discussion of recent data analysis and modeling efforts, we invite contributions on general magnetospheric processes at the Terrestrial planets. This includes, but is not limited to: solar wind-magnetosphere interactions, atmospheric escape, magnetosphere-ionosphere coupling, plasma acceleration and transport, magnetic reconnection, magnetotail dynamics, and bow shock physics. We strongly encourage comparative studies between planetary magnetospheres throughout the solar system. Results from various missions such as MESSENGER, BepiColombo, VEX, MMS, MEX, MGS, MAVEN, and more, are actively solicited.

Astrobiology is the study of whether present or past life exists elsewhere in the universe. To understand how life can begin in space, it is essential to know what organic compounds were likely available, and how they interacted with the planetary environment. This session seeks papers that offer existing/novel theoretical models or computational works that address the chemical and environmental conditions relevant to astrobiology on terrestrial planets/moons or ocean worlds, along with other theoretical, experimental, and observational works related to the emergence and development of Life in the Universe. This includes work related to prebiotic chemistry, the chemistry of early life, the biogeochemistry of life’s interaction with its environment, chemistry associated with biosignatures and their false positives, and chemistry pertinent to conditions that could possibly harbor life (e.g. Titan, Enceladus, Europa, TRAPPIST-1, habitable exoplanets, etc.). Understanding how the planetary environment has influenced the evolution of life and how biological processes have changed the environment is an essential part of any study of the origin and search for signs of life. Major Space Agencies identified planetary habitability and the search for evidence of life as a key component of their scientific missions in the next two decades. The development of instrumentation and technology to support the search for complex organic molecules and the endurance of life in space environments is critical to define unambiguous approaches to life detection over a broad range of planetary environments.

This session welcomes abstracts from several scientific domains such as prebiotic and interstellar chemistry, micropaleontology, limits of life, habitability, and biosignature detection.

Earth analogues are natural field sites with conditions that resemble one or more conditions found in planetary bodies. The importance of those extreme sites are crucial for study limits of life, habitability and for the space missions tools and techniques test before flying. Those extreme sites can be interpreted as natural laboratories. This session also welcomes abstracts on scientific investigations in planetary analogues fieldwork that are being carried out with Unmanned Aerial Vehicles (UAVs) a.k.a. drones.

Late posters Terrestrial Planets (TP)