Powerful particles and tugging tides may affect extraterrestrial life
(PHYSorg.com Space & Earth)

Since its discovery in 2016, planetary scientists have been excited about TRAPPIST-1, a system where seven Earth-sized rocky planets orbit a cool star. Three of the planets are in the habitable zone, the region of space where liquid water can flow on the planets` surfaces. But two new studies by scientists in the University of Arizona`s Lunar and Planetary Laboratory may lead astronomers to redefine the habitable zone for TRAPPIST-1.