Dazzling waves of color are lighting up the skies coast to coast for the second night in a row in the U.S. Americans from Colorado to Texas are sharing their images of the northern lights display. David Muir reports. https://abcnews.link/doOvozW | ABC World News Tonight with David Muir

Actor Chris Hemsworth is opening up about his father's battle with Alzheimer's and his own heightened risk of developing the disease. James Longman reports on their road trip together and what they're hoping to learn together. https://abcnews.go.com/ | ABC World News Tonight with David Muir