Voyager 1 passes 100 AU

Voyager 1, the nuclear powered spacecraft has just reached 100 AU (Astronomical Units = the distance from the Earth to the Sun or 93 million miles). That is a distance of around 9 thousand million miles from the Earth!
It is the outer most solar system, in a region called the heliosheath. If you imagine a vast bubble around the solar system, the heliosheath is the outer layer. The outmost layer of the bubble is the heliopause, the boundary to intersteller space.
The hubble space telescope has detected similar bubbles surronding other stars & solar systems.
So we have some frame of reference, easy as it is to imagine when looking at one of these hubble images, that you are looking at our solar system.
Both the Voyager probes will be travelling effortlessly through space for millions of years, possibly for thousands of millions of years, of even until the death of the universe.
They will, no doubt one day be the only evidence in the universe that human beings ever existed.
Voyager is an apt name for this amazing spacecraft and a reminder of what we can achievable through ambition, knowledge, resources, understanding and physics.