The bright sun overhead was leaning down hard. The heat on my skin felt like I was standing too close to a fire. Each step took patience, as I tried to find footholds on the softening snow.
We'd been at it for hours, trying to cross a broad alpine valley between two sharp ridges. I looked up for a moment to fill my lungs and adjust the heavy pack. The snowfield stretched into the distance, broken only by bare fields of scree. For a moment, I felt like I was walking in some alien world.
Then, I realized I was.
I'm spending the month of June in Seattle working on one paper about astrobiology and the Anthropocene and another about the death of stars, like the sun. But, last weekend I went backpacking with two old friends through Garibaldi Provincial Park in British Columbia. We spent three days gaining and then losing altitude in some of the most spectacular landscapes I have ever seen. Moving from forest to meadows to open rock, I was reminded of something powerful that has been hiding within my new research emphasis on astrobiology.
This planet is an alien world.
The last few decades have been a wake-up call for humanity in a number of ways. On the one hand, we have come to understand the complex interplay between Earth's governing systems of air, water, rock and life. We've assembled a detailed history of the evolution of those systems going back more than 3 billion years and found, in the process, how our activity is altering those systems in the present. At the same time, we've been discovering new planets wholesale and, within just a decade or two, we will be able to characterize their atmospheres with enough fidelity to understand their climates and conditions (including evidence for life). And in our own cosmic neck of the woods, the rovers and landers and orbiters we've sent to other worlds in the solar system have revealed landscapes of stunning beauty and scale.
Put it all together and we've entered a new age of planets. All these new worlds. All these new possibilities.
Which brings me (and you) back to our home. It's summer, and that means it's time to get outside. There are afternoon picnics and days at the beach, strolls in the park and walks in the woods. This year, as you find yourself outdoors, I would like to invite you to try something different. This year, try seeing the familiar as the new. Try seeing the Earth for what it truly is. Imagine, as you stand on a shoreline or watch a sunset, that this is just one of the billions of worlds astronomers now know populate the galaxy. Imagine it is just one of countless planets hosting a vibrant interplay of winds and water and warming radiation from its home star.
Imagine all that — and know that it's true.
Of course, we don't yet know if there are other "green" worlds out there where a biosphere has taken hold (maybe some of them are purple or red or some other photosynthetic variation). But even without including life, we can all now be certain that there are countless planets out there. Our Earth is, therefore, just another one of them.
In a very real way, you are standing on just another "alien" world (it would be alien to somebody out there). That simple fact can illuminate everything you see this summer with a new and poignant clarity. There are so many worlds to explore in the galaxy — and all of them must be stunning and vast and grand in their own way. This is just the one we get to start with.
How lucky for us all.
Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described "evangelist of science." You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4.