What is the heliopause?

The heliopause denotes the boundary of the solar system, or the edge of the Sun's gravitational pull; it is located somewhere beyond the Oort cloud, approximately 100 astronomical units from the Sun; it is approximately 123 astronomical units from the Sun; one astronomical unit is the average distance, or about 150 million kilometers, between the Sun and Earth.

The heliopause is the outer boundary of the heliosphere, where the solar wind, a stream of charged particles emitted by the Sun, meets the interstellar medium. It marks the point where the Sun's influence ends and the influence of interstellar space begins.

The heliopause is the outer boundary of the heliosphere, which is the vast region of space dominated by the Sun's influence. It marks the point where the solar wind, a stream of charged particles emitted by the Sun, collides with the interstellar medium, the gas and dust that fills the space between stars. At the heliopause, the pressure of the interstellar medium balances the pressure of the solar wind, creating a boundary region. Beyond the heliopause lies interstellar space, where the influence of the Sun diminishes significantly.