the.com/termination shock
where the sun's wind finally loses a fight it's been winning for billions of miles.
means the boundary in space where the solar wind abruptly slows from supersonic to subsonic as it slams into interstellar gas.
from named by analogy to the shock a jet makes breaking the sound barrier, first observed directly when voyager 1 crossed it in 2004, about 94 astronomical units out.
voyager crossingvoyager 1 hit it in december 2004
distanceroughly 8 billion miles from the sun
speed dropsolar wind slows from 400 to under 100 km per second
not the edgeheliopause, the true boundary, lies further out