In 1977 NASA launched two spacecrafts known respectively as Voyager 1 and Voyager 2.

The mission of these spacecrafts was to go boldly where no spacecraft has ever been before – to the heliosphere. The heliosphere is a magnetic bubble of charged particles in the space surrounding our solar system and solar wind. It is a region 8-14 billion miles away from the sun.

35 years after the two Voyagers were launched, data published by NASA suggests that Voyager 1 has in fact managed to travel all the way to the heliosheath – the outermost layer in the heliosphere.

The graph below from NASA shows an increased rise in the galactic cosmic rays from outside our solar system in recent months:

Galactic cosmic ray increase

There has also been a very dramatic drop in the number of charged particles originating from the Sun:

There has been a decrease in the number of charged particles originating from the Sun

These two graphs suggest that Voyager 1 is travelling further and further away from our sun and our solar system.

Scientists are still working on determining whether or not there has been a change in the direction of the magnetic field affecting Voyager 1. If this is confirmed then it will be almost definitive that Voyager 1 has in fact reached the boundaries of the solar system.

Why is this of interest to us?

The heliopause is a region that has never before been reached by any spacecraft or anything from Earth.

If all goes to plan the Voyagers have enough electrical power and fuel to operate until 2020, so they could potentially explore the Milky Way. By the end of Voyager 1’s journey it will have travelled 12.4 billion miles away from the sun.

This data taken from Voyager 1 will allow us to gain a deeper insight into what is going on at the edge of our solar system and beyond.