On November 30, 2022, Prof. Alain THOREL presented an online science and technology lecture entitled Astronomy and Materials to the students of ICARE. More than 140 students attended the lecture.

In his conference, Prof. Alain THOREL proposed to take the students to a journey through the solar system, and to find how the solar system fits into our galaxy - the Milky Way -, and how galaxies fit into the universe. He started his conference with a question he used to ask his students at PSL: where does iron come from? The students used to easily answer: in the iron mines! Then he used to ask another question: where does the iron from the iron mines come from? The ancient Greeks believed that iron came from the sky, and that the sky was made of iron. It is well known today that iron effectively comes from space, as some students were aware of. Then he used to ask a third question: where does the iron from space come from? Usually no answer from the students. This is a complicated question that Prof Alain THOREL explained during his conference, the answer of which establishes an intimate link between us and the stars, and the universe, between a simple nanocrystal and the galaxies in spite of many orders of magnitude of scale difference. He concluded his talk by probably the most important philosophical question: Are we alone?

At the end of the lecture, students put forward questions such as "How all chemical elements are produced", "How can we discover a new chemical element", "when was the last chemical element discovered" and "how to detect valuable chemical elements". Professor Alain patiently answers them one by one.