Nikku Madhusudhan, a professor of astrophysics and exoplanetary science at the University of Cambridge, discusses the discovery of hints of life found on the distant planet K2-18b. Subscribe to ABC News on YouTube: https://abcnews.visitlink.me/59aJ1G Watch 24/7 coverage of breaking news and live events on ABC News Live: https://www.youtube.com/watch?v=gN0PZCe-kwQ&ab_channel=ABCNews Watch full episodes of World News Tonight with David Muir here: https://youtube.com/playlist?list=PLQOa26lW-