NASA'S mission to touch Moon

As of my last knowledge update in September 2021, NASA's Parker Solar Probe is the mission closest to "touching" the Sun. The Parker Solar Probe, launched on August 12, 2018, is designed to study the Sun's outer atmosphere, known as the corona, and gather information about solar wind, solar flares, and other solar phenomena. While it doesn't physically touch the Sun's surface due to the Sun's intense heat, it gets remarkably close in comparison to any previous mission.