Hello, Is This Planet Earth?

Introduction

One of the remarkable things about seeing the Earth from space is that by day, with the naked eye, it's very hard to spot any signs of human habitation.

Instead, our planet reveals itself as a vast geological puzzle, its features spanning entire continents, sculpted by nature's forces and the passage of time. Wind and rare precipitation have shaped the Sahara into a canvas of exquisite art, with sand dunes towering over 150 meters high clearly visible from space. Volcanoes trace the outline of Earth's tectonic plates, often smoking gently and giving away the presence of an active core not far beneath. Glaciers carve out entire mountain ranges as they grind inexorably towards the oceans. By night it's a different story. You can easily trace the pattern of human migration and settlement by the lights of towns, cities, motorways and man-made structures. Even our thirst for the planet's resources stands out—the lights of a thousand fishing boats in the Gulf of Thailand or the dazzling oil fields in the Middle East.

It's impossible to look down on Earth from space and not be mesmerized by the fragile beauty of our planet. I was struck by just how thin our atmosphere really is—that tiny strip of gas that sustains all life and differentiates our planet from the barren, hostile conditions of Mars or Venus. I became determined to share this unique perspective of the one place we can all call home. It may come as a surprise to learn that I was not a keen photographer when I launched into space. It's not that I didn't enjoy photography; it's just that I never seemed to have a good eye for a picture. In that respect I have a lot to thank planet Earth for: she's a beautiful subject and made my job extremely easy! Even my early attempts rewarded me with some stunning vistas—the Cascade mountains, frozen sea in the Hudson Bay and spectacular sunrises to name a few.

From the International Space Station (ISS) you can see over 1000 kilometers in any direction. Passing over the French Alps I could enjoy a view stretching from Greece to the UK with just the turn of my head. At first, the magnitude of this scene was a bit overwhelming, and my photographic skills did not extend much beyond "point and shoot." However, as I settled into this new environment my perspective began to change. With sixteen orbits every day, it was not long before I felt I knew planet Earth pretty well! For example, it may sound strange, but I was talking about Madagascar recently—somewhere I have yet to visit—with the familiarity of someone who has traveled there extensively. I began to focus on the details: noting the mountain lakes in the Himalayas that would lead me to Mount Everest, perhaps, or checking up on some small volcano in Kamchatka to see if it was still erupting. When traveling at nearly 30,000 kilometers per hour, this level of detail requires some careful planning.

Each morning, I would check to see where the ISS would be passing over, decide which pictures I would try to capture that day and then set several alarms to remind me. Often, my alarm would go off and I'd have my hands full of a science experiment or be in the middle of a maintenance activity—a case of "better luck next time." However, there was a huge sense of satisfaction when all the planning paid off and I was rewarded with a perfectly lit overhead pass of the Pyramids, say, or a rare glimpse of Antarctica. As much as I enjoyed the hunt for those more elusive targets, many of my most treasured pictures were not the result of meticulous planning. Often I would just happen to be passing by the Cupola window and be struck by the most incredible view—a sea of thick green fog as we traveled through the aurora borealis or the disco lights of a hundred lightning flashes along a massive storm front.

Night photography in low-light conditions presented a new set of difficulties. Reflections from the numerous light sources inside the ISS were a constant problem. We used a blackout curtain around the window with a hole for the lens to poke through to prevent this from ruining a picture. The next challenge was how to get a shot in sharp focus with long exposure times and so much relative motion between the camera and the object. The best method relied mainly upon a steady hand and a good eye for tracking targets—something for which my previous job as a helicopter pilot had prepared me quite well. As someone who had only ever used "auto" mode on a camera before, I never imagined that I would be intuitively adjusting aperture, shutter speeds and ISO settings depending on the rapidly changing lighting conditions, nor discussing the merits of a particular lens over dinner in space with my fellow astronauts. Camaraderie on a space station is clearly important and photography is one of the many common interests that astronauts from all nations can share. In the first few weeks on board the ISS, my pictures certainly owed a great deal to the patient advice of crewmates Scott Kelly and Tim Kopra.

Our camera of choice on the ISS is the Nikon D4. This is an amazing piece of equipment with a 16.4 megapixel resolution and highly sensitive image sensor, making it perfect for low-light situations. The ISS is well-stocked with a variety of lenses, but I tended to stick to a staple diet of 28mm, 50-500mm, 400mm and 800mm lenses. We tried not to change lenses too often—dust and particles don't sink to the floor in microgravity and so it's easy to introduce contaminants into the camera when it's exposed.

Another problem is radiation. On the ISS we are above much of Earth's magnetic field, which is protecting you right now from radiation. Not only are we bombarded by solar particles, but also by extremely energetic galactic cosmic radiation from deep space. At night we would often see streaks of light when we closed our eyes—very pretty until you realize a small part of your retina has just been smashed by a proton. Our cameras suffer the same impacts too. Over time, we see a degradation in picture quality with more and more dead pixels showing up—a sure sign that it's time to replace the camera.

The ISS is packed with cutting-edge technology, including Wi-Fi with an Internet connection to Earth via satellite. However, this is extremely slow and it would sometimes take minutes just to view one web page. This was problematic when it came to trying to identify pictures. It's one thing to know that you're somewhere over Europe and in less than twenty minutes will be coasting out over the Indian Ocean; however, when you have a picture of a lake and some volcanoes that could be anywhere within a 1000-kilometer radius, I often wished for just a few moments with Google Earth to come to the rescue. Instead, a paperback Rand McNally World Atlas would be passed between crew quarters most evenings as we struggled to identify some of the more obscure landmarks. One of the great things about sharing these images on social media was that there were always people willing to help with the research and fill in any missing details behind the pictures.

One of the most iconic images captured from space is called "Earthrise," a photograph taken by Apollo 8 astronaut Bill Anders as they emerged from the dark side of the moon and saw Earth rising over the horizon. Anders famously said, "We came all this way to explore the moon, and the most important thing is that we discovered the Earth." This book captures my personal journey of discovery, not just the discovery of planet Earth—a stunning oasis of life in the vastness of space—but also the discovery of a newfound passion for photography. Looking back now, it seems strange that I didn't expect taking pictures to have a major impact on me. How wrong I was.

We so often think of the world as divided into countries and peoples, but when you look at the planet from space you don't notice borders or the divisions of continents. The only divisions we see are those crafted by nature, 4.5 billion years in the making. An incredible sequence of events enabled intelligent life to evolve on Earth, allowing us to develop the technology necessary to leave the sanctuary of our home planet and to reflect upon our existence from the unique vantage point of space. I hope that these images fire your imagination like they have mine. And I hope that I am able to share with you some of the same sense of awe that I first experienced when looking down on planet Earth.

Growing up, I was fortunate to have fantastic support from my parents, and the right opportunities that enabled me to follow a career that I was passionate about. But I know I am one of the lucky ones. Thousands of disadvantaged young people in the UK are facing issues such as unemployment, homelessness or mental health problems and need help to turn their lives around and fulfill their potential. The Prince's Trust is an amazing organization that gives young people the chance to succeed. As an Ambassador for the Trust, I'm delighted that all my proceeds from the sale of this book will be donated to this deserving charity.