Earth (the little dot in the upper right), as seen in scattered yellow sunlight from a distance of more than 6 billion kilometers, by the Voyager 1 probe as it departed our solar system. // NASA/JPL
All good things must come to an end. It's been an honor and a pleasure to guest-blog on BoingBoing for the past two weeks, and to engage with so many of you on topics near and dear to my heart. We talked about why the existence of extraterrestrial life is the most thrilling question humans can now answer. We noticed thousands of missing terrestrial planets, and found out how to find them. We discussed science communication, and astrobiology's asymptotic frontier. We weighed the worth of our world, and then crunched the numbers on some new exoplanets. We visited the Earth-like future of Saturn's moon, Titan, and learned the real science behind the forest moon of Endor. We explored a Keplerian orrery, and found new ways to visualize exoplanet data. We saw the birthing pangs of planets. We debated the most promising nearby stars, and wondered how we might one day reach them.
Special thanks goes out to those who directly or indirectly helped with these entries: Maggie Koerth-Baker, Rob Beschizza, Jer Thorp, Debra Fischer, Greg Laughlin, David Kipping, Dan Fabrycky, Sara Seager, and Lucianne Walkowicz and the rest of the Kepler science team. Thank you. And thanks to all of you reading this, particularly those of you who joined the discussion and passed story links around. I appreciate your attention and your interest.
There was much more I wished to write about and say, and indeed there will be one more multi-part post coming soon, but for now it's time to step aside. I hope all of you will keep reading, keep looking up, and start following and talking with me on Twitter. For media-related inquiries on commissions, reprints, and the like, I can be reached via FirstInitialFollowedByLastName at Google's e-mail service.
A final thought: In these past two weeks, our world has significantly changed—not only in Egypt, with the crowdsourced revolution that led to the fall of an autocrat, Hosni Mubarak, but also with the news from NASA's Kepler mission, which hinted that our universe is likely brimming with other living planets. The writing isn't on the wall so much as it's in the stars: We are not alone.
The juxtaposition of these two events inescapably brings to mind Voyager 1's famed "Pale Blue Dot" image of Earth from the depths of space, and Carl Sagan's timeless meditation on its meaning. It has been oft-quoted, but bears repeating:
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 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.
Sagan's words are a summation of the value of a cosmic perspective, and I doubt they will ever be surpassed in their eloquence. I'll leave you with them.