- It is an astrographic feature.
- It forms the extreme outer edge of a system, lying close to the region dominated by the Oort Clouds.
The Heliopause is the boundary marking one of the outer limits of a star's influence. It is the region where the bubble of solar wind particles begin to press into the interstellar medium and slow down, so that they are traveling slower than the speed of sound relative to the star. As it is compressed it becomes much hotter. It also carries outward some of the Sun's magnetic field, which gets stronger and becomes twisted.
- The termination shock represents the region where the velocities of particles fall to subsonic speeds.
The Heliopause is very important to vessels using Solar Sails since it represents a border beyond which many lower technology solar sailing ships cannot exceed. In some ways, poets liken Heliopause to the edge of the world for solar sailing ships.