The heliopause is the boundary where the solar wind from the Sun slows down and merges with the interstellar medium. It marks the outer edge of the heliosphere, which is the bubble-like region of space dominated by the solar wind. Beyond this boundary, the influence of the solar wind diminishes, and the environment is primarily shaped by the surrounding interstellar gas and cosmic rays. This region is significant for understanding the interaction between our solar system and the rest of the galaxy. The Voyager 1 spacecraft, launched in 1977, was the first human-made object to cross the heliopause, providing valuable data about this distant frontier and the nature of interstellar space.