Life, Birth
Though it was initially thought infeasible, on this date the first child is born on Mars. His parents came over 3 years previously, and had met on the trip over.
This is a historic occasion, as it marks when the Mars colony goes from a base to a true colony. While many thought it would not be possible, subsequent data shows that 0.38 g is enough, however, the child has slightly weaker muscles and are taller. However, these children cannot walk under Earth gravity without an exosuit, or at least a year of training and supplements. Otherwise, they grow up healthy, on a brand new world.