Heliopause

Heliopause is the boundary between the heliosphere and the LISM. When solar winds approach this blurred region, they slow abruptly causing a shock wave to form known as the solar wind termination shock. For the first ten billion kilometres of its radius, the solar wind travels at over 1,000,000 km/h. As it begins to interact with the interstellar medium, it slows down before finally ceasing altogether. Here the solar wind’s strength is no longer great enough to push back the stellar winds of the surrounding stars.