Yarkovsky and YORP effects simulation on 3200 Phaethon.

We carry out a numerical study on the thermal behaviour of asteroid 3200 Phaethon, the parent body of the Geminid meteor shower. Phaethon's orbit is highly eccentric, with the perihelion distance as small as [Formula: see text]. During the perihelion passage the surface temperature rises so much that the reaction force of the thermal radiation from its surface affects Phaethon's orbital and spin motion.

Highly porous nature of a primitive asteroid revealed by thermal imaging.

Carbonaceous (C-type) asteroids are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites and are essential for understanding planetary formation processes.