BOULEY , Sylvain

Ages of geological units of planetary bodies are determined from impact crater counts on their surface. These ages are model-dependent, and several models largely used in the community assume a constant production function and a constant cratering rate over the last 3 Ga. We have mapped the population of small impact craters (>200 m in...

IntroductionPlanetary surfaces not protected by dense atmospheres suffered by many impacts by asteroids and comets, leaving craters as a reminders of it. Among all craters observed on surfaces of Earth, Mars, Moon, and Venus, about 3-4% are binary craters. It is believed they formed by the simultaneous impacts of the two components of binary...

Over the last decades, a significant number of small asteroids (diameter <10 km) having a satellite in orbit around them have been discovered. This population of binary asteroids has very specific properties (secondary-to-primary diameter ratio of about 0.3, semi-major axis to primary diameter ratio around 2 and an obliquity of the system close...

On 5-6 June 2012, Venus will be transiting the Sun for the last time in this century. This unique opportunity, besides offering the opportunity of investigating the mesosphere of the planet, also provides a significant nearby analog of exoplanet transits. Several studies using the transmission spectroscopy technique have provided significant...

During the Venus transit in 2004 several observers collected data useful to the characterization of the mesosphere of the planet, by observing the solar light refracted at the corresponding altitude range. The "aureole" thus formed, is observable during the ingress and egress phases of the transit, when Venus is crossing the solar limb. For the...