On Monday, December 2, 2024, Dr. Kosmas Gazeas, Lecturer of Observational Astrophysics of the Department of Physics at the National and Kapodistrian University of Athens, was a guest speaker of the Athens College High School Astronomy Club.

Mr. Gazeas' speech was on the subject of our Solar System. Members of the club had the opportunity to learn about the structure of the Solar System, the different regions into which we divide it in order to study it (habitable zone, main asteroid belt, Kuiper belt, Oort cloud) and the mechanism behind its creation. At the same time, they discussed with Mr. Gazeas the different types of planets and celestial bodies, such as the rocky planets (Mercury, Venus, Earth, Mars) and the gas giants (Jupiter, Saturn, Uranus, Neptune), the nature of the rings found in all four gas giants, and the existence of dwarf planets (which now include Pluto) and other asteroids.

Students were particularly impressed by the distinction between asteroids, meteorites and comets and more specifically by the hypothesis that the water found on Earth which is a necessary condition for life, may have come from successive collisions of our planet with comets in the distant past. Finally, students also dealt with the nature of the Sun, as well as with open problems in astrophysics. The students were particularly interested in the sharp increase in temperature between the chromosphere and the solar corona, even though the solar corona is farther away from the Sun's core.

Through this activity, students had the opportunity to broaden their knowledge of astronomy and to be inspired by the beauty and mystery of the sky.