Letters of Intent received in 2022

LoI 2024-2164
Planetary science and origin of life in the era of James Webb Space Telescope

Topics

- Detection and characterization of Exoplanets from ground- and space-based telescopes
- Exoplanet atmospheres: Theories and observations
- The planets of the Solar System – including their magnetospheres.
- Small bodies of Solar System (comets, KBOs, rings, asteroids, meteorites, and dust)
- Circumplanetary systems and evolution of the Protoplanetary Disk
- Dynamic Habitability and astrobiology
- Education and Outreach in exobiology and planetary science

Rationale

Planetary science is an array of scientific disciplines that collectively seek to answer questions about how the Solar System formed, what initial conditions and subsequent processes shape how planetary bodies evolve and interact with each other and the environment, and how these factors enabled the conditions for life to form on at least one planet in the solar system. The latter feeds into the growing field of “astrobiology”, the study of the origin and evolution of life on planetary bodies. To understand how life can begin in space, it is essential to know what organic compounds were likely to have been available, and how they interacted with the planetary environment. 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 survivability of life in space environments is critical to define unambiguous approaches to life detection over a broad range of planetary environments.

Over the past few decades, planetary science has been revolutionized with the discovery of over 5,000
confirmed extrasolar planets, of a variety of sizes and masses extending beyond that of the solar system’s inventory—enabled in large part by the Kepler mission and the Transiting Exoplanet Survey Satellite (TESS). Yet many of these exoplanets may be more Venus-like than Earth-like because our current observation techniques are biased towards detecting and observing planets relatively close to their stars. The James Webb Space Telescope (hereafter JWST) has already started observing high-priority exoplanet targets. JWST is uniquely primed to unravel the mysteries of the star and planet formation processes and make breakthrough discoveries in exoplanet and planetary science and the origins of life. JWST is designed around four main science themes, two of which are central in exoplanet and planetary science studies. (i) The Birth of Stars and Protoplanetary Systems theme is to unravel the birth and early evolution of stars, from in fall on to dust-enshrouded protostars, to the genesis of planetary systems. (ii) The Planetary Systems and Origins of Life theme is to determine the physical and chemical properties of planetary systems and investigate the potential for the origins of life in those systems.

JWST is uniquely primed to solve these mysteries in planetary science. It is designed to observe the atmosphere of exoplanets by combination of its high-resolution observing modes, imaging, spectroscopy (including transit spectroscopy) and coronographic capabilities, and superb near and mid-IR sensitivity. JWST is particularly important, since it will provide a large aperture, a heliocentric orbit, and continuous wavelength coverage from 0.6 to 28 microns. It should be powerful enough to make possible detailed atmospheric characterization not only of hot Jupiters but also of planets of smaller size and more temperate, even including some terrestrial planets recently found orbiting in the habitable zone of nearby very-low-mass red dwarfs. Its spectral coverage and high precision should enable measuring the abundances of key molecules by transient spectroscopy, and to place tight constraints on atmospheres’ vertical and horizontal structures by occultation and phase curve spectroscopy. It will be able to characterize a large diversity of planets in terms of mass, size, irradiation, and host star properties. Its observations of transiting exoplanets will bring tight constraints on current theories of planet formation, evolution, and, to some extent, habitability. JWST's planetary exploration also includes a rich Solar System science case that includes imaging and spectroscopic characterization of Mars and the outer planets (Jupiter, Saturn, Uranus, and Neptune—including their magnetospheres), Kuiper belt objects, dwarf planets, Solar System moons, ocean worlds, asteroids, comets, and rings. The analysis of small bodies in the inner Solar System can provide key insights into how the chemical inventories (e.g., organics and volatiles) of early Earth may have evolved. The subsequent emergence of life and its evolution from the first self-replicators to the last universal common ancestor of all modern life, represents a critical period when geochemistry and biochemistry were likely inseparable. Understanding this interdependence of the earliest forms of life and their environment helps constrain the range of geochemical conditions whence life could emerge.

The purpose of this proposed IAU Symposium is to bring together and connect the observational astronomers, especially those interested in using JWST to perform planetary science observations (exoplanet, Solar System planets, small bodies …), and the theoretical astronomers aiming to constrain their theories with JWST observational results. Whereas these individual disciplines have rapidly evolved over the past decade, the interaction between the different communities has been limited and therefore the knowledge of the development in other fields is often lacking. A better understanding of the latest insights in these rapidly evolving fields will highly benefit our understanding of planet formation and exploring life beyond Earth. Invited talks and reviews will cover both the observational and theoretical sides, the ultimate goal of the symposium being to optimize the communication between the experts of both sides, and thus to maximize the scientific return. The Symposium will cover a broad range of topics within a 5-day program (including half-day excursion).

Life beyond Earth attracts the interest and curiosity of scientists, philosophers and the general public alike. A special session of the symposium will therefore be dedicated to training in the field of planetology and exobiology as well as the dissemination of knowledge in this field by education and outreach.