Dazzling photographs and images from space of our planet’s nightlights have captivated public attention for decades. In such images, patterns are immediately seen based on the presence or absence of light: a distinct coastline, bodies of water recognizable by their dark silhouettes, and the faint tendrils of roads and highways emanating from the brilliant blobs of light that are our modern, well-lit cities.

For nearly 25 years, satellite images of Earth at night have served as a fundamental research tool, while also stoking public curiosity. These images paint an expansive and revealing picture, showing how humans have illuminated and shaped the planet in profound ways since the invention of the light bulb 140 years ago.

These lights and the darkness tell stories about our planet—stories that this volume will present for your consideration. Earth at Night will show how humans and natural phenomena light up the darkness, and how and why scientists have observed Earth’s nightlights for more than four decades using both their own eyes and spaceborne instruments. It is an engaging and fascinating story; come along for the adventure!