There are some places in the solar system no human will ever go. The surface of Venus, with its thick atmosphere and crushing pressure, is all but inaccessible. The outer worlds, such as Pluto, are too remote to presently consider for anything but robotic exploration. And the sun, our bright burning ball of hydrogen and helium, is far too hot and tumultuous for astronauts to closely approach. In our place, one intrepid robotic explorer, the Parker Solar Probe, has been performing a series of dramatic swoops toward our star, reaching…