IntroductionFor Neil Armstrong, going to the edge meant walking on the moon. For Jane Goodall, the edge meant studying chimps in Tanzania. For Edmund Hillary and Tenzing Norgay, it meant summiting Everest. For Amelia Earhart, it meant circumnavigating the globe.
So, what is “the edge”?
Andrés Ruzo thought he knew the answer. A geothermal scientist, Ruzo trekked through the Amazon to chase down the legend of a “boiling river” that once haunted conquistadors. The river was not on any maps, and many believed it to be a myth. When Ruzo discovered this river that boiled—emitting vapors that glowed in the moonlight—he stood at what he thought was the edge. But now those words meant something else entirely. “The world is bigger, more incredible, and more mind-blowing than I could ever have imagined,” says Ruzo. “Awe lies at the edge—the edge is where you find God.”
If you ask one hundred explorers to define the edge, you’ll get one hundred different answers. This is not an exaggeration, and this is not theoretical. While preparing this book, we asked members of The Explorers Club—the home to the world’s greatest explorers since 1904—to share their own meaning of the edge.
Over 140 explorers responded. For one mountaineer, the edge means “not knowing if you will live to see tomorrow.” Others view it as an internal challenge. “Pushing my limits taught me resilience,” says Meg Haywood Sullivan. “Growth occurs when challenging the boundaries of emotional security, physical comfort, and the status quo.”
The edge can refer to the edge of a cliff, the edge of consciousness, the edge of the known world. But almost every edge has one thing in common. “The edge means risk,” says Will Roseman, the Club’s longtime executive director. And it’s the explorer’s job to calculate and manage and minimize risk, weighing the pros and cons of climbing that next ridge. Sometimes the plan goes sideways. And when it does, says Roseman, “It takes all their wits and all their efforts to save themselves from falling off that edge.”
We’re fascinated by the edge, in part, because it strips away the quotidian aspects of “normal” life, highlighting the most dramatic aspects of exploration. “The edge is the place, one step past what you think you can endure, where humanity is distilled into its strongest stuff,” says Donna Oliver, who, in 1975, became the first woman to solo-winter in the Antarctic Circle.
This book shares excerpts from letters showcasing this “strongest stuff,” as well as their accompanying stories. Many of these are gripping tales of adventure, yes, but they’re also something more, something deeper, something universal. By seeing how world-class explorers operate at the edge, we can gain insights, instruction, and inspiration for how we can navigate the edges in our own lives.
For all of us have our own version of the edge. “The edge, to me, is that invisible, theoretical, metaphorical boundary that defines your comfort zone,” says lifelong hiker J. R. Harris. “Some people like to stay at its center, where life is more stable and comfortably consistent. Others, like me, like to explore the periphery, where life is less predictable but more exciting.”
This book also explores what it’s really like to navigate the edge— with the spotlight on actual flesh-and-blood human beings, not exalted heroes. (Even if these humans are in many ways heroic.) So we’ll get into the grime and the weeds and the muck. “The edge is not always full of glory, like some people may think,” says Jessica Glass, whose letters from the edge include salty details like “New PhD low: fishing in the Seychelles Islands on a researcher’s budget, casting under a bridge at 5:30 a.m. with no luck, as you stand under a sewage pipe that periodically reeks of shit and—best part—sprays sewer water on you.”
And that brings us to the letters themselves. For millennia, explorers have wandered from their homes and then sent dispatches from afar. These letters have helped us move the needle of human knowledge. Charles Darwin could not write
On the Origin of Species, for example, without first traveling to Patagonia, exploring its ecosystem, and then scribbling his thoughts in a series of letters. An explorer’s work isn’t finished when she reaches a new destination or makes a discovery; she needs to somehow share what she’s learned.
From the Silk Road to rovers on Mars, letters have always told the tale. But they do more than that. Letters give us comfort in the knowledge that the explorer is alive and safe—or warn us when they are not. Letters can be intimate. They provide the benefit of immediacy, giving unfiltered insight into what the explorer was feeling in the moment, whether excitement or fear or despair or wonder. They allow us to clearly hear the voice of the explorer, sometimes in triumph and sometimes from the grave.
For millennia, letters from the edge were exactly what they sound like: handwritten notes on sheets of paper. Technology changed, but the concept endured. So we’ll widen the scope of “letters” to include all the ways that explorers have captured their thoughts and shared them with the world: email, text messages, field journals, blog posts, ham radio, tweets, scientific studies, fax, telegrams, drawings, data packets from space, and holograms intended to reach the far side of the galaxy.
Yet, in one final sense, the letters are not really about the far side of the galaxy or even the edge. They have a secret dual purpose. When explorers go to the edge, they’re on a quest to learn something. That could be discovering the South Pole, researching climate change, studying other cultures, or rocketing through space. They share what they’ve discovered, and the world is enriched by that knowledge. Even probes to distant corners of the universe, ultimately, help us better understand Earth’s place in the cosmos. For astrophysicist Gregory Matloff, the edge means that “The universe is huge, and we are tiny. We can’t conquer it, but we can explore it.”
Going to the edge, paradoxically, is a way to gain perspective at the center. Understanding the edge is a way to understand ourselves.
Copyright © 2025 by The Explorers Club and Jeff Wilser. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.