Voyager 1, the most distant man made object from Earth is approaching the edge of the Solar System, and is expected to cross it in less than five years.
Voyager 1 was launched in 1977 initially to have a look at Jupiter and Saturn, but after it had done this, the project team used a technique called "slingshot" to send the craft around Jupiter and off towards the Galactic centre, just to see what they would see on the way. So far, it has seen very little, but has confirmed Einstein's relativity, and Kepler's laws of motion. Neither of which actually needed any more confirmation to convince anybody.
Despite being a veritable antique, Voyager remains Earth's most distinguished space-craft, and it's current speed, would be expected to reach the Galactic centre in one hundred and thirty billion years, by which point the black hole at the centre of the galaxy is expected to have evaporated. It is currently travelling at a whopping seventeen kilometres a second. This speed would see the journey time from England to Australia slashed to a mere fifteen minutes, although there may be some slow down around Milton Keynes due to the roundabouts and speed cameras.
The edge of the Solar System is caused the Heliopause, and is where the particles from the sun smash into particles from all the other stars in the galaxy. Here the temperature is expected to soar to -200ºC and there will be, in the words of NASA scientists, "some buffeting". The edge of the Heliopause has been reached now, and nobody knows how thick it is. It could take up to five years to break through, or it could be through by next Tuesday at quarter past five GMT.
If Voyager survives the buffeting it will become the first man-made object in interstellar space.
"We don't know what to expect once we get beyond the safety of our Solar System," said Voyager Director Carry Bhargs. "There could be a galactic police force that does us for speeding or littering!"