I recently heard a fascinating radio program about the Voyager spacecraft. Voyager 1 and its sibling Voyager 2 were launched in 1977 for the purpose of gathering information about the outer planets of our solar system and the vast space beyond.
Several years ago the probes completed their primary missions and now continue to hurtle outward. Voyager 1, which is ahead of Voyager 2, has now reached the outer limits of the heliosphere; the bubble of plasma and magnetic fields released by our sun (also known as the solar wind). The edge of the heliosphere is called the heliosheath: a region of turbulence as the outward pressure of the solar wind collides with the inward pressure of interstellar forces. And then further out, at the edge of the edge, is the heliopause: a point where the outward and inward pressures are at calm equilibrium. Beyond that, outside of the sun's bubble of influence, is interstellar space. Scientists aren't quite sure if Voyager 1 is in the heliosheath or the heliopause, since these distinctions are somewhat theoretical. Eventually, however, it will pass through to become the first human-made object to escape the heliosphere and reach interstellar space.
It occurred to me that I feel an odd little sense of affinity--at least from a theological/philosophical perspective--with the Voyager craft; on a trajectory of exploration beyond what I know and understand, into a space where boundaries aren't clear and the familiar powers of centralized forces are diminishing.