TRAPPIST-1 is older than our solar system
(PHYSorg.com Space & Earth)

If we want to know more about whether life could survive on a planet outside our solar system, it`s important to know the age of its star. Young stars have frequent releases of high-energy radiation called flares that can zap their planets` surfaces. If the planets are newly formed, their orbits may also be unstable. On the other hand, planets orbiting older stars have survived the spate of youthful flares, but have also been exposed to the ravages of stellar radiation for a longer period of time.