It was on my first birthday that the Voyager 1 spacecraft turned around and took a picture of the pale blue dot we call home. That picture was Voyager's last glimpse of Earth before its camera was switched off and it began to sail, uninterrupted, towards interstellar space. Around the same time Voyager 2 finished its tour of the outer planets and joined Voyager 1 on its interstellar mission.

So by the time I came to learn about the Voyager spacecraft they were both well on their way to the edge of the solar system. Now one of them might have finally left.

I wrote about Voyager for my entry into this year's Wellcome Trust Science Writing Prize, in association with the Guardian and the Observer. My entry – Beyond the edge of the solar system – was shortlisted and is up on the Wellcome Trust blog today.

And just in time! It looks as if, after all that waiting, Voyager 1 has finally broken through to the other side. It's not quite official yet, but a huge drop in the number charged particles hitting Voyager 1 indicated that it passed through some kind of boundary around the start of September. Data from its magnetometer will be needed to confirm what exactly has happened, but I will be keeping my eyes peeled for an announcement soon.