NASA has replaced two bigwigs in its human spaceflight program, just a week after releasing a report criticizing how the agency handled the first crewed flight of Boeing's Starliner astronaut taxi.
The Solar System's icy moons are a focal point in our search for habitability and life. Among them are Europa, Ganymede, and Callisto, all Galilean moons of Jupiter. Their environmental conditions play a big role in potential habitability, but so does chemistry. Without the right molecular building blocks, life can't get started.

