As most of you likely heard (and if you haven’t, GOOD NEWS), after more than a year of disappointing headlines, which were promptly retracted; Voyager 1 FINALLY broke through the charged particles surrounding our solar system – officially reaching “interstellar space.” At least; it reached what we believe to be interstellar space. Oddly enough, this region isn’t well-defined. Regardless of the semantics, this is still a pretty monumental occasion. After all.. we – as in, humankind – built something that now wanders the space between stars. How cool is that?
So, in celebration of the Voyager program, we have complied some cliff notes about Voyager 1.
This small fact – not just in regards to Voyager, but the entire space program – never ceases to amaze me. These incredible feats of technology, which are designed to withstand the harsh environment of space (Jupiter was one of the biggest obstacles facing Voyager 1, as the gas-giant is encased in high energy radiation), are powered by a computing system with less memory than today’s average cell phone. That’s right; a 40 year old spacecraft that has traversed our solar system has about 240,000 times less memory than today’s Iphone 5. (Voyager has approximately 40 KB of memory)
Before Voyager 1 and 2 set sail for the stars, special golden disks were created to travel along with them into interstellar space. The contents of the said disks were selected by a NASA committee, led by Carl Sagan. (Who I can’t help but think about each time I read about the Voyager probes. The project meant so much to him, I just know that he would be thrilled with the news) Together, they chose 116 various images of Earth, Earth’s people, our animals and a variety of sounds, which include those made by wind, thunder and animals; like song birds and whales. They also added a collection of music by artists such as Beethoven, Mozart, Stravinksy and Blind Willie Johnson – with audio clips of greetings in 55 different languages.
Attached to the records, some information of scientific importance was relayed. Some of these included information about the mathematical and physical qualities our solar system and its planets, along with the location of our solar system in respect to 14 pulsars, whose precise pulsation periods are even given. Also attached to both is a plaque containing a few words from President Jimmy Carter. It says: “This is a present from a small, distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours.”
However, the most little-known tidbit about the record deals with Sagan and his soon-to-be-wife, Ann Druyan. Sagan and Druyan thought it would be interesting to include an EEG on the disk, on the off chance that an alien civilization WOULD find it – and perhaps be capable of reading human thoughts. Ann had prepared a script to recite during the process, but just prior to its recording – on In June 1, 1977 (just three months before Voyager’s launch) – she and Sagan discussed getting married over the phone. This would have an obvious effect on the outcome of the EEG. Ann herself even said, “My feelings as a 27 year old woman, madly fallen in love, they’re on that record. It’s forever. It’ll be true 100 million years from now. For me Voyager is a kind of joy so powerful, it robs you of your fear of death”.
As mentioned before, the boundary separating our solar system from actual interstellar space is not well defined (hence so much confusion about Voyager’s position, in respect to the inner and outer portion of our local neighborhood). While now, the general consensus is that it DID break free, it still has a lot of traveling to do before the sun is behind it – with the rest of the galaxy in front of it. To clarify what I mean, see this image:
This artist rendering depicts the distances separating objects in our solar system – starting with the orbit of each of the planets, voyager’s position in respect to it and the outermost portion, which Voyager is still a LONG way from getting through. The scale bar is in astronomical units (with 1 AU representative of the approximate distance separating the sun and Earth: 93 million miles [or 150 million kilometers]). Each rung is about ten times the distance of the previous one.
Now, with that in mind; Neptune – the most distant planet in our solar system – is about 30 AU from the sun. And since I know some of you will ask, Pluto (poor lil’ dwarf gets excluded from the fun stuff) is around the same distance on average. (At its most distant point, it can be about 49.3 AU from the sun) As you can clearly see, Voyager 1 has surpassed all of the planets; coming in at a staggering distance of 125 AU (this is about 11.62 billion miles (18.7 billion km) from the sun!) Yet, it still isn’t anywhere near the Oort cloud – home of the icy comets.
Assuming no major surprises are ahead, it will still take 300 YEARS for Voyager to reach the Oort cloud. Moving onward, it might take 30,000 years to fly beyond it! If you think that’s crazy….
Apart from our own sun, our next celestial neighbor resides in the Alpha Centauri system (okay. technically, this is a triple star system, but you get the idea) – some 4.3 light-years (or about 25.6 trillion miles) away. (Or, since we’ve been using astronomical units, Alpha Centauri is about 300,000 AU’s from the sun). If we scale Earth down to a grain of sand, then Alpha Centauri would be over 6 miles – or 10 kilometers – away. Meaning.. Alpha Centauri is ridiculously far away in human terms. In fact – it’s so far away that it would take light, traveling at the universal speed limit, 4.3 years to journey there. As we know, nothing travels faster than the speed of light – not least of all the Voyager spacecraft. Traveling at its current speed, it would take Voyager 1 at LEAST 73,000 years to come anywhere near Alpha Centauri – IF the spacecraft was even headed in that direction.
Currently it isn’t. It is, however, headed to the same general vicinity a neighboring star is expected to arrive to in the distant future . You shouldn’t expect a postcard though – as it would take at least 40,000 years for Voyager to travel within 1.6 light-years (9.3 trillion miles) of the star in question- known as AC+79 3888, a dim red-dwarf in the constellation of Camelopardalis. not that that matters since:
Currently, the Voyager 1 spacecraft is powered by three nuclear batteries, known as radioisotope thermoelectric generators. They operate by converting heat released by the decay of plutonium-238 fuel into electricity. (Plutonium-238 decays with a half life of about 87.7 years). In 2001, it was revealed that the power source on both Voyagers were diminishing unexpectedly – only performing at 67% of their original capacity, instead of the expected 83.4% – leading some to believe that in another ten years, the batteries will no longer power the spacecraft – causing each of the remaining four functional instruments to shut down. This would prohibit us from making any additional contact with the spacecraft – as well as keeping the spacecraft from relaying data back to Earth from interstellar space.
However, one comforting thing to remember is that long after we are gone; after the sun becomes a red-giant, engulfing the inner planets and incinerating the remnants of Earth (“the only home we’ve ever know”), Voyager will remain. A piece of Earth will remain. Even if the spacecraft is relegated to roaming the celestial abyss for the rest of eternity – without another hapless species stumbling upon it – Voyager is still a part of us. It immortalizes us, even after the body of the last living homosapien is destroyed. That, my friends, is Voyager’s legacy.
“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.”