In May of 1977, the blockbuster film "Star Wars" hit movie screens, telling a tale set a long time ago in a galaxy far, far away. In August and September of that year, the Voyager 1 and Voyager 2 spacecraft were launched on their journeys through the solar system and beyond. It was a long time ago and the galaxies remain far, far away, but that is where the two pioneering spacecraft, still sending signals back home, are heading.
Earlier this month, NASA scientists reported that Voyager 1 had entered a region of space that appears to be a transitional phase between the solar system and interstellar space. Scientists call this region a "magnetic highway" because charged particles from the Sun are racing out as charged particles from the space between the stars are racing in. When the magnetic highway comes to an end, the spacecraft will have presumably have left the solar system, although astronomers caution that they are truly in uncharted territory in interpreting Voyager 1 data.
The U.S. space program is capable of inspiring awe -- primarily in the 1960s and 1970s of course -- and the achievements of the Voyagers are awe-inspiring in terms of the accomplishments of the scientific community and the wonders of space. Since their launching, "Star Wars" has been followed by followed by five films (two sequels and three prequels) and Disney has bought the franchise. Jimmy Carter was president when the spacecraft left earth and Barack Obama was 16 years of age. Yet after 35 years, the two nuclear-powered Voyagers (each equipped with a ‘70s era eight-track tape recorder) are still able to relay data back to earth on the charged particles racing around them and will be able to do so, scientists estimate, until 2020, when they will have presumably rocketed out of the solar system.
That the Voyagers, traveling for 35 years at roughly 36,000 miles per hour, are still within our solar system testifies to the awesome immensity of the universe. Voyager 1 is 11 billion miles from the sun yet it remains on the fringe of a solar system that is a small part of a galaxy, which is in turn just one galaxy among many millions. It will take the two spacecraft an estimated 40,000 years to reach the closest star. The home base of the Voyagers is indeed a tiny, fragile place in the midst of this void. The odds would suggest that there must be someone else out there somewhere in that vastness, but they would be so far away it is unlikely that we would ever meet.
The Voyagers were launched on a mission to tour the outer planets of the solar system which they did successfully -- everything they have done after that and will do is gravy. The spacecraft sent back extraordinary photos of the red spot of Jupiter and the beautiful rings of Saturn, along with their remarkable moons. Only the Hubble Telescope photographs of far-off galaxies have rivaled them in their majesty. After checking out Saturn, Voyager 1 used its gravitational pull to slingshot toward the outer reaches of the solar system. Voyager 2 detoured to photograph the outer planets of Uranus and Neptune before heading toward interstellar space which is why it is, and presumably always will be, 2 billion miles behind its sibling.
The cameras that shot those landmark photographs no longer function, but the Voyagers fly on relentlessly, providing scientists whatever information they can. Soon they will dip humanity’s first toe into the vast reaches of interstellar space -- and then step forward.