Guest post by Don Lincoln
“Space: the final frontier,” is the opening passage of the venerable television show Star Trek, a show which depicted mankind’s triumphant conquering of interstellar space. However, before that bright and shiny future becomes possible, our species must make our first halting foray beyond our planetary neighborhood. It appears that a probe called Voyager I, launched by NASA in 1977, has finally stepped outside the protected confines of our solar system, beginning humanity’s exploration of the galaxy.
So what kind of galaxy will Voyager encounter? Will it be teeming with life, as envisioned by Star Trek and Star Wars aficionados? Will Voyager bump into an interstellar superhighway, full of UFOs and flying saucers heading toward Earth to abduct and examine our fellow men? Or will it drift slowly into space, reaching ever more distant and lonely environs?
Well, I am sad to tell you that the prediction is that Voyager’s flight will be a cold and barren one. Space is big, and the probe’s velocity is rather small. In about 40,000 years, the probe will pass within 1.6 light years of Gliese 445, a red dwarf currently about 17.6 light years away that is quickly approaching the region of the sun. When Voyager encounters Gliese 445, it will be only about three and a half light years from the Earth at the closest approach before it recedes again into the distance. Unfortunately, with only a decade or two of power left, Voyager will have fallen forever mute.
Gliese 445’s stature as a red dwarf makes it an unlikely candidate for life as we know it and perhaps life of any kind. Recent evidence from the Kepler satellite has bolstered the belief that planets are common in the universe, but the existence of life is still uncertain. The fact that life formed soon after the Earth cooled enough to sustain liquid water suggests that perhaps life is common in the cosmos. This is conjecture, but informed conjecture.
Scientists have spent the last half a century and more not merely speculating about alien life, but looking for evidence of the existence of intelligent extraterrestrials. Starting with the whimsically-named Ozma project (named because of author Frank Baum’s claim that he was using radio to speak with fictional Oz), scientist have used enormous radio receivers to scan the heavens looking for a faint signal that might indicate we are not alone. In spite of decades of effort, no such evidence has been found. By no means should this lack of evidence be considered proof that the stars are uninhabited, although it does make the bar scene in the first Star Wars movie seem rather unlikely.
The transition of Voyager from inside the solar system into interstellar space marks a moment in history in which mankind has taken its first tentative steps outside the stellar nest from which we came. True interstellar travel may elude us forever, or we may decide to follow Voyager into the void. It will take considerable effort, first of the astronomical sort, to find a new home, followed by an unparalleled engineering challenge to overcome the incredible difficulties of long and slow travel to the stars. And faster than light travel is unlikely to simplify the journey. While faster than light travel might be something that some clever mind might discover, it is more likely that we’ll travel outside the Solar System the old fashioned way.
The realities of real space travel are more difficult than the dreams of fiction. But that doesn’t diminish the achievement of those NASA engineers who launched Voyager over 35 years ago and sent their craft farther than they ever expected. Mankind’s first probe has entered interstellar space. Let’s hope it’s not the last.
A Fermilab senior scientist, Don Lincoln‘s research focuses primarily on subatomic particles. A prolific advocate of conveying scientific knowledge to lay persons, Dr. Lincoln has published hundreds of scientific papers and three books—including the newly released Alien Universe: Extraterrestrial Life in Our Minds and in the Cosmos and The Quantum Frontier: The Large Hadron Collider, which he is currently in the process of updating. He regularly produces videos explaining everything from the Higgs boson to supersymmetry, dark matter, and antimatter.