THIS WEEK
Dr. Franck Marchis
Senior Researcher at SETI Institute
“Tiny Moons around Asteroids”
After decades of speculation, the existence of multiple asteroids---asteroids with one or several companions around them---has been observationally confirmed thanks to the advanced imaging capabilities of large telescopes. Asteroid multiplicity is an astronomical prize for observers and theorists alike, since it helps constrain theories on the origin of our solar system. I will briefly describe the adaptive optics technology which is used today on the very Large Telescope (UT4-8m) at ESO-Paranal (Chile) and the Keck-II 10m telescope and the 8m-Gemini North telescope at Mauna Kea (Hawaii). These powerful instruments provide capabilities to image several multiple asteroid systems. Today more than 200 companions of asteroids are known, and half of them were discovered by large worldwide network of professional and amateur astronomers equipped with small and medium size telescopes. By detection of small dip in brightness due to mutual eclipse events, these surveys give us the opportunity to better understand these fascinating mini-planetary systems. NASA and ESA space agencies are seriously thinking of developing missions to explore in-situ these new worlds.