heliosheath

astronomy

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Last updated

July 16, 2026

Quick Summary

The heliosheath is the region of the heliosphere where the solar wind slows down after passing the termination shock. The heliosphere itself is the vast region surrounding the Sun and solar system, filled with the Sun's magnetic field and charged particles from the solar wind.1

This region extends far beyond the planets, with the heliopause marking its outer boundary, approximately 123 astronomical units from the Sun. Spacecraft like Voyager 1 and 2 have traversed this boundary, providing valuable data about the heliosheath and its interaction with the interstellar medium. The heliosheath is a transitional zone where the solar wind's outward pressure is balanced by the pressure of the interstellar medium.12

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heliosphere
…wind slows is called the heliosheath. Neutral atoms in the heliosheath form a “ribbon” that is probably caused by solar wind particles being reflected back into the solar system by the magnetic field in the ISM. At the outward boundary of the heliosheath is the heliopause, where the outward pressure…
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…wind slows is called the heliosheath. Neutral atoms in the heliosheath form a “ribbon” that is probably caused by solar wind particles being reflected back into the solar system by the magnetic field in the ISM. At the outward boundary of the heliosheath is the heliopause, where the outward pressure…
Read More