The Final Frontier: Voyager 1 Enters Interstellar Space

Voyager 1 and 2 were launched in 1977 to explore the outer planets. Now 11 billion miles from Earth and still sending data, Voyager 1 just left the Solar System.If you've read "The Higgs Boson 'God Particle': Of All Things Visible and Invisible," or any of my excursions into cosmology and astronomy on These Stone Walls, then you're either anxiously awaiting this new addition to my science posts, or yawning while reaching for your mouse to click it away. Resist that latter temptation, please, because I happen to think this is one of the coolest stories of 2012.Of course, I WOULD think that, but I also know that not everyone joins me in my paranormal quest to make faith and science a little less mutually exclusive. If nothing else, then at least be consoled by the fact that of my 180 posts for TSW to date - not including the occasional re-run - only four have been about science. Okay, one was science fiction and I'm not counting that one. It was an Advent post titled "Phasers on Stun, Mr. Spock! Captain Kirk's Star Trek Epiphany." Whether you're a trekkie or not, it's a good post for the upcoming Advent.According to our friend, Pornchai, my four science posts comprise just 2.2% of all my posts on These Stone Walls. Pornchai spontaneously calculated that figure in his everexpanding head when I read him the above paragraph. Ever since receiving that diploma with high honors that I wrote of last week, Pornchai's been sounding a bit like Mr. Spock just out of StarFleet Academy. I've even noticed a slight pointing of the ears. Anyway, please don't click me away just yet. I'll try to keep my geeky science posts at 2.2%.WHAT JUST HAPPENED?To understand what Voyager 1 has just accomplished, a short primer on the mechanics of our Solar System is needed. You know that our planet is in orbit around the Sun, and completes one orbit every 365 days plus a few hours. To compensate for the few extra hours, our calendar adds an extra day every four years. In addition to that movement around the Sun, which we experience as change in the seasons, our Solar System and everything in it also travels at a speed of 450,000 miles per hour in orbit around the center of the Milky Way galaxy.At that rate of speed, our Solar System completes one orbit around the Milky Way's galactic center roughly once every 200 million years. We don't experience traveling through space at that speed because we're fixed by gravity on the Earth's surface which in turn is fixed by gravity in orbit around our Sun. It's sort of like being in a car speeding down a highway. From our perspective, the car is moving relative to the highway while we're sitting still.What moves along with the Sun in this vast orbit around the center of this galaxy is not just the matter we can see - the Sun with its eight planets (Pluto has been demoted) and their moons, and all the asteroids and debris we call the Oort Cloud - but also the entire region of space under our Sun's influence. This region is called the heliosphere, a gigantic bubble of space controlled by the Sun and its magnetic field and all its charged particles called solar winds.For the first time in human history, a man-made object - Voyager 1 - has broken through this bubble to enter the interstellar medium, a place to which, as Star Trek once put it, “No one has gone before." In "A Quiet, Faraway Milestone for Humanity," (The Wall Street Journal, October 19) Arizona State University science professor Lawrence Krause described this milestone:

"Has Voyager broken through the sun's bubble and reached the vast interstellar medium on its way to eternity? The Jet Propulsion Laboratory has three criteria for establishing that this has happened: The stream of particles coming from the sun should fall off, the stream of particles coming from the galaxy should increase, and the direction of the magnetic field surrounding [Voyager] should change."

By October, all three criteria had been reached by Voyager 1. Now it is traveling through space beyond the influence of our Sun 11 billions miles from where Voyager started in 1977, and it is still sending back data. It will continue to transmit data until its onboard transmitter's power source fails in another decade or so, but that's a decade of science about interstellar space that mankind has never before detected.Even after that decade, Voyager will continue traveling at its current rate of speed. To give you an idea of the vastness of this galaxy - one of billions of galaxies in the known Universe - in about 50,000 years Voyager 1 will be closer to our closest neighboring star than to our Sun. In about 300,000 years, Voyager will pass within a few light years of Sirius, the "Dog Star" that I described in "These Stone Walls' Second Annual Stuck Inside Literary Award," and the brightest star we can see from Earth.A SPACE ODYSSEYThis milestone for Voyager is a very big deal for science and for planet Earth, but there's also something humbling about it. TSW readers of a certain age will remember the great 1968 film masterpiece, "2001: A Space Odyssey" for which producer/director Stanley Kubrick won an Oscar for Best Visual Effects in 1969. Based on a novella by science fiction legend, Arthur C. Clarke entitled, The Sentinel, "2001: A Space Odyssey" was Stanley Kubrick's 1968 vision of what human space travel would look like by 2001.It included commercial airline shuttle flights to a giant space station in orbit around Earth, excavations on the dark side of the Moon, and a science crew sent in cryogenic stasis to the moons of Jupiter shepherded by two pilots played by Keir Dullea and Gary Lockwood. They were guided on the mission by HAL-9000, a computer (Mac or PC? You decide!) suffering a nervous breakdown. "Open the pod bay doors, Hal," ordered stranded astronaut, David Bowman (Keir Dullea). "I'm sorry, Dave, but I can't do that," HAL-9000 calmly replied.When the real 2001 came and went, the reality of space travel was not even close to what Arthur C. Clarke and Stanley Kubrick envisioned. NASA's manned Apollo lunar landings had been abandoned decades earlier, and the only orbiting space station, a tin can next to Kubrick's vision, was Russian.Voyager's real space odyssey of 2012 might be a lot less glamorous than manned flights to the moons of Jupiter, but it's still a great moment in human history. For the very first time, an object created by human beings has left our Solar System to begin a journey into space beyond the influence of our star, the Sun. Voyager has passed at last into what Star Trek called "The Final Frontier." For science fiction buffs, that might seem one small step for man, but for science itself, it's one giant leap for mankind.WHY 1977?Once every 176 years, the five outer planets of our Solar System - Jupiter, Saturn, Uranus, Neptune, and the now downgraded Pluto - are aligned in such a pattern that a spacecraft launched from Earth to Jupiter at just the right time would be able to visit the other planets using a slingshot trick of physics called "gravity assist."The Voyager 1 and 2 planetary probes were launched in the summer of 1977 to take advantage of this rare alignment. The next opportunity would have been the year 2153. Voyager 2 was actually launched first on August 20, 1977 followed by Voyager 1 on September 5. They were named in reverse order because it was calculated that Voyager 1 would overtake Voyager 2 after reaching Jupiter in March of 1979.The slingshot effect of "gravity assist" shot Voyager 1 away from Jupiter for a flyby of Saturn in 1980, Uranus in 1985, and then Pluto in 1989, while Voyager 2 took a slingshot from Uranus to Neptune. After visiting Pluto in August of 1989, it took Voyager 1 another 23 years to reach and break through the outer limits of the Solar System, something that happened last month."GREETINGS FROM PLANET EARTH"Voyager 1, followed by Voyager 2 in another year or so, will wander through the galaxy for potentially millions of years. Each 825-kilogram probe contains an array of scientific instruments but each also contains a record of us, and of life on Earth.A copper phonograph record stored aboard Voyager 1 has a message from (then) President Jimmy Carter, the sounds of whales, elephants, chimpanzees and other animals, and a sampling of Earth's music - a bit of everything from Bach to Mozart to Chuck Berry singing "Johnny Be Good."The record also contains the message, "Hello from the Children of Planet Earth" in 55 languages, and a collection of photographs including a map of the Solar System and Earth's location. Whoever thought of that last detail apparently hadn't seen the film, "Invaders from Mars" that I described in "A Glorious Mystery for When the Dark Night Rises." We should be more careful where we advertise for tourists.WHO'S OUT THERE?Of course, if you read my post, "E.T. and the Fermi Paradox: Are We Alone in the Cosmos?" then you know where I stand on the chances that Voyager will ever be seen by anything other than human eyes. Those chances are slim to none. Voyager 1 is traveling through space faster than any object ever created by mankind, and yet in one million years it will have traveled a mere 47 light years from our Sun. That's less than one-half of 1/1,000th of the distance across the galaxy we live in, and there are billions of other galaxies.If such numbers are humbling, it's because they should be. As a race, we haven't decided yet which we're going to find more Earth shattering: to discover that we are not alone in the cosmos, or to never discover anyone but ourselves.The far more likely way any such discovery will be made - or not be made - will be via radio astronomy and not through some chance alien encounter with Voyager 1. In 2014, the world's largest and most sensitive radio astronomy facility, known as the Square Kilometer Array, will be shared by Australian and South African scientists. It will shed light on cosmological mysteries such as dark matter and dark energy, but also will greatly expand SETI, the Search for Extraterrestrial Intelligence. Human kind will either make a breakthrough, or just continue the utter silence that SETI projects have thus far discovered everywhere they've looked and listened in this galaxy for over eight decades.I still predict the latter outcome, and it's not because I don't want to believe there's other life out there. All available evidence thus far points to only one or two conclusions: Either life like us is unique on a galactic scale, or it is exceedingly rare.Still, there's something vaguely comforting in the milestone of Voyager 1 - in the fact that a post card from the human race is out there now to drift forever among the vast ocean of stars like a message in a bottle. As Voyager carries our greeting into eternity, human kind might want to revisit the notion that we are meant to live in the image and likeness of God. That places upon us a responsibility in the cosmos that we must live up to. What an irony that in the 21st Century human kind scours the Universe for signs of life while on Earth we have let rise up a culture of death.We have work to do on accepting and living out the dignity and honor God intends for us. We have work to do on the value with which we view life on Earth before we seek out new life and new civilizations; before we boldly go where no one has gone before.