Imagine looking out your window and seeing the swirling colorful clouds of Jupiter. That could be the vista for one of the grandest adventures of the next 100 years. Over the course of the next 75 years, humans will likely land on Mars and perhaps even scale Olympus Mons, the largest volcano in the solar system, but it will be Jupiter and the oceans within its moons that drive humans to explore out beyond the asteroid belt. 

The goal will be simple but profound: retrieve a sample of alien life from beneath the icy shell that covers Europa’s global liquid water ocean. Robotic emissaries will have completed much of the reconnaissance, but for the final step—getting a sample of living life—humans may need to be in the loop.

Humans will go into orbit around Jupiter just beyond Callisto, the fourth of Jupiter’s large moons, and launch a submersible coupled to a melt probe that will land on Europa, a moon slightly smaller than Earth’s moon. It will melt through the ice, and then astronauts will take control of its movement and direct it to swim through the ocean to collect data and samples. The samples will then have to be brought back to the surface and launched to the base camp spacecraft, where the astronauts will be eagerly awaiting a revolutionary moment in science. They'll examine any retrieved samples for signs of life.

It's anybody's guess as to what we'll find. Europan microbes? Europan jellyfish? Whatever it is, it would be a sample from a second origin of life and such a discovery would mean that we live in a biological universe—one in which life arises wherever the conditions are right.