SPACE: Are Aliens Watching Us?
Picture this: A hundred million years ago, an advanced civilization detects strange signatures of life on a blue-green planet not so far away from their home in the Milky Way. They try sending signals, but whatever’s marching around on that unknown world isn’t responding. So, the curious galactic explorers try something different. They send a robotic probe to a small, quiet space rock orbiting near the life-rich planet, just to keep an eye on things. If a story like this played out at any moment in Earth’s 4.5 billion-year history, it just might have left an archaeological record. At least, … Read more