Beyond Earth: A Chronicle of Deep Space Exploration

Abstract

Humans abandoned their nomadic habits and moved into settlements about 40 to 50 thou- sand years ago. We have been using tools even longer. But our ability to send one of our tools into the heavens is of much more recent origin, spanning only the past 60 years. Yet, in that time, we have created new tools—we call them robotic spacecraft—and sent them into the cosmos, far beyond Earth. Of course, many never got very far. That’s the cost of hubris and ambition. But most did. And many never came back to Earth and never will. In that sense, we as a species have already left a mark on the heavens; these small objects that dot the cosmos are a permanent legacy of our species, existing for millions of years, even if we as a planet were to disappear. This book that you hold in your hands (or are reading in digital form) is a chronicle of all these tools, both failed and successful, that humans have flung into the heav- ens beyond Earth.