"Where there's water on Earth, you find life as we know it. So if you find water somewhere else, it becomes a remarkable draw to look closer to see if life of any kind is there, even if it's bacterial, which would be extraordinary for the field of biology."
American astrophysicist and science communicator. He serves as director of the Hayden Planetarium in New York and has hosted and produced science programming and media. He is widely known for public education work in astronomy.