I wrote about the Cassini mission at Saturn near the beginning of my science writing career, and ever since then I’ve been on the mission’s email list. I get updates whenever Cassini takes cool new photos, and this past summer, I found out ahead of time that the spacecraft would be turning around to take a picture of Earth on July 19, 2013. I was in the car at the appointed time, but I opened the window, and waved at the sky.
When Odyssey magazine decided to put together an issue on “the Earth from space,” I knew Cassini’s photo, titled “The Day the Earth Smiled” had to be included. It was great fun to learn about the process that allows a spacecraft a billion miles away to take pictures and send them back to Earth, but my favorite part of the article is that I got to quote Carl Sagan.
Back in 1990, the Voyager 1 team took a picture of the Earth from space, called Pale Blue Dot. It’s much blurrier than the new Cassini photo, but it’s famous for what it meant, and for what Sagan said about it. I could only include a few lines in the article, but I’ve got plenty of room in this blog post. What he said is worth reading again and again:
“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.
The Earth is a very small stage in a vast cosmic arena. 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. 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.
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.”