This sample of asteroids is the most extensive and best resolved we have to date. The observations reveal a great diversity of particular shapes, ranging from the classical sphere to the dog bone, and allow astronomers to trace the geographical origin of asteroids within our Solar System.
The acquisition of detailed images of these 42 objects by terrestrial telescopes constitutes a tremendous advance in the study of asteroids, and contributes to answer the question of Life, the Universe, and Everything.
The small number of detailed observations of asteroids that we had until now prevented us from accessing their main characteristics such as their 3D shape or their density. Between 2017 and 2019, Vernazza and his team involving IMCCE researchers and engineers set out to close this gap by conducting an in-depth study of the main bodies in the asteroid belt.
These discoveries were made possible by the extreme sensitivity of the SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument installed on the ESO VLT. "The increased performance of SPHERE, combined with our limited knowledge of the shape of the largest asteroids in the main belt, has allowed us to make substantial progress in this field," adds Laurent Jorda of the Laboratoire d’Astrophysique de Marseille, co-author of the study.
Astronomers will be able to acquire detailed images of a larger number of asteroids when the ELT (Extremely Large Telescope), currently under construction in Chile, becomes operational at the end of this decade. "Observations of main-belt asteroids with the ELT will allow us to study objects with smaller diameters, between 35 and 80 kilometers depending on their spatial location, as well as craters with dimensions between 10 and 25 kilometers," concludes Vernazza. "Having an instrument like SPHERE on the ELT would allow us to image even a similar sample of objects in the Kuiper Belt. In other words, we will be able to characterize the geological history of a larger sample of small bodies from the Earth’s surface."