by Marie Gueguen & François Lique, on

Presentation of the event

The Espace des sciences of Rennes is a cultural site dedicated to the popularization of science. Its primary objective is to address social issues and shed light on the advancements made in modern science. Through its diverse range of approaches, the center maintains a harmonious balance among various scientific fields. Every Tuesday, the Espace des Sciences welcomes esteemed speakers who share their expertise and present their research topics.

M. Gueguen, F. Lique and. S. were invited to present their work in a presentation on Tuesday, 28th of February 2023. A replay of their presentation, given in French, is available on Youtube at the following link:

Que connaissons-nous des corps célestes aujourd'hui ? - M. Gueguen, F. Lique, and S. Le Picard

How can scientists establish facts about the matter that constitutes astrophysical objects that they cannot manipulate ?

The chemical composition of the atmospheres of planets and comets is usually studied through their radiation, which can only be interpreted in the light of data produced in laboratories, far from the real and extreme conditions of the environments where such objects are found. It is not surprising that each space probe sent on site has brought back its share of spectacular discoveries! But then, if in situ measurements are irreplaceable, how can we hope to acquire any scientific knowledge of objects on which we will never go ?

During this presentation, the speakers discussed the observational facilities used to study astrophysical media and explained the process of manipulating captured images to extract valuable information about the astrophysical media. Marie elaborated on the construction of models in fields where direct measurements are unavailable but observations are present; François demonstrated how the light captured by telescopes can be manipulated into direct informations about physical and chemical conditions in a media, and Sébastien presented how models are enriched through the exemple of the model of Titan atmosphere.