The planet Mars shares its orbit with a handful of small asteroids, the so-called Trojans. Among them, one finds a unique group, all moving in very similar orbits, suggesting that they originated from the same object. But the mechanism that produced this “family” has been a mystery. Now, an international team of astronomers believe they have identified the culprit: sunlight. Their findings, which highlight how small asteroids near the Sun may evolve, are to be presented at the annual Meeting of the Division of Planetary Sciences of the American Astronomical Society at Provo, Utah this week, by Dr. Apostolos Christou, a Research Astronomer at the Armagh Observatory and Planetarium in Northern Ireland, United Kingdom and leader of the research team.