We’re not quite sure where our solar system ends. We know that it does end: at some point our sun’s magnetic field ceases to influence particles in space. But that point isn’t a nice, clean, line in the sand. And while we do know that there is space beyond the influence of our sun, we haven’t yet been there.
But we’re getting close.
In 1977 NASA launched Voyager I and II. The original intent was a fly-by of some of the most outlying planets of our solar system – Jupiter, Saturn, Uranus, and Neptune. Voyager I only passed the first two, but Voyager II flew by all four. But these two probes have enough fuel to run until around 2025, so in 1989 the mission was extended: to go beyond our solar system.
Right now, they’re getting close. They are in what is called the “heliosheath” which is a section of our solar system where the influence of the sun decreases dramatically. If the calculations and hypotheses are correct, they should pass the outer edge of our solar system, the heliopause – “helio” meaning “sun” and “pause” meaning “cessation” – within a few years. They would be 12 billion miles from the sun. That would be 12,000,000,000 miles.
Attached to both Voyagers are golden disks – which contain, in analog, pictures from Earth, greetings from world leaders and children, mathematics, music and much more. If these probes are ever found, by who or whatever might be out there, humans might, after all, be remembered though we may be long gone as a species.
I find myself both amazed and critical.
I am amazed because 12 billion miles is a distance I cannot even wrap my head around. It is so beyond my sphere of knowledge and conceptualization, that I have to accept that it is simply incredible. What is even more incredible is that these probes that are currently out there in the heliosheath were built in 1977. Let me hip you to some other things that happened in 1977: Roots began its run on ABC; Fleetwood Mac releases Rumours; Star Wars open in theatres; Elvis Presley retires, and later dies; Groucho Marx dies; Atari 2600 released; Orlando Bloom, Shakira, Kanye West, Tom Brady, Ludacris, and PSY were born. This wasn’t the age of iPads, which I am still convinced have a helipad hidden in there somewhere. This was the age of pelvis gyrating and PBBB sandwiches – that would be peanut butter, banana and bacon for those of you who don’t follow Elvis Presley’s eating habits. I find it a little mind-blowing that these probes are still going, and accomplishing what they are accomplishing.
Yet, when you think about it, it isn’t much. We are just now reaching the outer edge of our solar system. That is a tiny fraction of the radius of the Milk Way galaxy. With great eyesight and a clear, pitch-black, night we can see 9 other galaxies. Which are just a fraction of the other galaxies out there. Thomas Edison said, “We don’t know one millionth of one percent about anything.” We are so far from the Star Wars and Star Trek scenarios, as much as it seems like a possibility whenever I see the movies.
And yet, if we can go from Atari to iPads in 36 years… maybe it’s not so outrageous.