When I was a kid (I now include teendom in this category), I would look up at the night sky and try to wrap my brain around the knowledge that those points of light are the past. They are so very far away that what I was seeing was literally many years old. (The closest star to us is Alpha Centauri, which is nearly four-and-a-half light-years away. This means, just in case you're unsure of the definition, that the light from Alpha Centauri takes almost 4.5 YEARS to be visible to us.) It was stunning to me. Most of these stars were bigger than our sun, but they're so far away that they're easily obscured by streetlights. How tiny is Earth? How tiny am I?
"When I was a kid." Ha. I still do this, constantly.
Voyager I was launched on September 5, 1977. Its primary mission was to study the gas giants of our solar system. Its secondary mission: send a message of peace and understanding into interstellar space, to be found, hopefully, by intelligent life. The form this greeting took was what became known as the "Golden Record."
When Voyager I passed Saturn in 1980, Carl Sagan, head of the Golden Record committee, asked that the spacecraft be turned around to take one last photo of Earth. He knew that the photo would have no real scientific value, because it was too far away to make out any detail, but he thought it would be an important image for understanding our place in the cosmos.
Most scientists on the Voyager Mission team thought it was far too risky, that taking a picture of Earth, so close to the sun, would irreparably damage the camera. It took ten years for the Voyager team to agree that it would be worthwhile, to recalibrate the instruments, and smooth out other assorted bumps.
On February 14, 1990, Voyager I was 6 billion km/3.7 million miles/40.5 AU from Earth when it took this photograph:
|The remarkable "Pale Blue Dot" photo. Yet another gift from Carl Sagan.|
See that tiny point of light in the far right sunbeam? That's the Earth.
In his 1994 book, Pale Blue Dot, Sagan wrote:
"From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again 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.
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity – in all this vastness – there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known."
I can't possibly add anything to this. Sagan was far more brilliant and eloquent than I'll ever be.
I suppose some people might find this depressing: we're so insignificant. I find it exhilarating: we're so insignificant. That's amazing. That's freeing. That makes all one's worries and disagreements and fears and mistakes even tinier. If you try something big, and you fail, it means nothing, compared to the vastness of the universe. If you confess your love for someone, the risk is infinitesimal. If you embarrass yourself, no one will remember it by the time the light of Alpha Centauri reaches the Earth.
This is us. We have to take care of each other, because this 0.12 pixel is all we have.
Voyage to Voyager, a multi-media play about the creation of the Voyager Golden Record, opens at the Gottlieb Planetarium in Union Station on Fri, July 17.