Physics

Interstellar medium

Galaxy

Solar wind

Astronomy

Energetic neutral atom

Interplanetary spaceflight

Astrophysics

Heliosphere

Quantum mechanics

Plasma

Astrobiology

Interplanetary medium

Space Science Reviews

The Voyager spacecraft have left the heliosphere and entered the interstellar medium, making the first observations of the termination shock, heliosheath, and heliopause. New Horizons is observing the solar wind in the outer heliosphere and making the first direct observations of solar wind pickup ions. This paper reviews the observations of the solar wind plasma and magnetic fields throughout the heliosphere and in the interstellar medium.

Observations of the Outer Heliosphere, Heliosheath, and Interstellar Medium