Por Efrem Maconi (University of Vienna, Austria).

As our Solar System orbits the Milky Way, it encounters Galactic environments with varying interstellar densities. The passage through dense clouds or supernova blast waves can leave traces on Earth, such as the deposition of radioactive isotopes in geological records. The Gaia mission has revolutionized our understanding of the local stellar neighborhood, revealing coherent gas structures such as the Radcliffe Wave and their motion in space. In our work, we show that the trajectory of the Sun intersected the Radcliffe Wave in the Orion star forming region and was once remarkably close to massive star clusters as they were forming. We estimate the crossing of the Radcliffe Wave to have occurred between 11.5 and 18.2 Myr ago, with the most likely time of the transit at approximately 14 Myr ago. This corresponds with a time-period of major reorganization in the Earth’s climate during the Middle Miocene. Our results provide a framework for future investigations into possible isotope anomalies in geological records.

Short bio: Efrem Maconi is an Italian PhD student at the University of Vienna. He is currently spending six months at the University of Lisbon, working with Prof. André Moitinho's group. His research focuses on the interstellar medium, open clusters, and Galactic weather.