This Friday, NASA reported that they believe the Voyager 1 space probe has reached the edge of our solar system. I’m really not sure why I only just discovered this (thanks Facebook nerds) – surely the fact that a man-made object has for the first time gone beyond the boundaries of our solar system should be big news?? As a friend of mine put it – ‘does this make us an interstellar species?’ I think it does… Wow.
It’s big news to me. The Voyager 1 and 2 probes were launched in 1977 – meaning they’ve been travelling for about the same length of time that my parents have been married (awww). In that time, Voyager 1 has reached a distance of 18 billion kilometres from the Sun, with its twin Voyager 2 (relatively) close behind at 15 billion kilometres. You can watch those kilometres flick by at about 17 per second on the Voyager mission’s official site.
The sensors on Voyager 1 have been showing a marked increase in charged particles thought to come from beyond the solar system – a sign that the probe has reached the edge of our little corner of the universe. As NASA rather beautifully put it, ‘Voyager scientists looking at this rapid rise draw closer to an inevitable but historic conclusion – that humanity’s first emissary to interstellar space is on the edge of our solar system,’ – weighty words for a genuinely awe-inspiring occasion (take that, Queen’s Jubilee).
I’ve been a cheerleader for the Voyager probes ever since I discovered that they carry with them a map to Earth (hello aliens!!), and recording of Johnny B. Goode by Chuck Berry as one of the shining examples of human culture. Frankly if any aliens fail to appreciate that song’s brilliance, I don’t want to meet them.
The information about Earth is on the rather grandly named ‘Golden Record’- literally a gold LP carrying a selection of sounds and images chosen to represent our planet by a committee chaired by Carl Sagan. What a task – I’m imagining it something like the hardest and most important job interview any of us could ever experience. How do you tell a possible alien lifeform or civilisation about Earth, about humanity, about everything? Luckily, Sagan wrote a book about how they approached this almost ludicrous project, called Murmurs of Earth, which I might have to track down…
I think the Voyager mission really embodies the best and greatest ideals of science. It is quite literally a voyage into the unknown, a symbol of our urge to explore, discover and learn about the world around us – wherever that might take us. 1977 was a long time ago, and I wonder whether a mission like this would get much public support if it was being set up now. I hope it would. Whatever the problems that consume humans on Earth, for me projects like this momentarily lift me out of my day-to-day mundane worries and remind me how awe-inspiring the world, the solar system, the universe we live in really is.
It will take 40,000 years for the Voyager probes to even be close to any other planetary system, once they have left ours. Their power supplies won’t last nearly that long – the probes will be able to send back information until around 2025. After that they will travel silently on, but we won’t hear from them again. Unless those Golden Records are actually ever seen by other eyes.
Sagan put it better than I can: ‘”The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet.’