A few weeks ago, International Space Station astronaut Soichi Noguchi took an amazing picture of Endeavour re-entering Earth's atmosphere.
He has been busily snapping away at the Earth and posting the pictures on his Twitter feed. You really should be following him!
Recently, he unknowingly did me a big favor by posting this incredible shot of Egypt:
Yes, those are actual pyramids in the picture! Amazing. And by doing that, he made it very easy for me to answer the question I still get about once a month from people: "Is the Great Wall of China the only man-made object you can see from space?".
I already knew the answer is no; you can see cities easily, as well as agricultural formations, big roads, and more. But this one shot makes it very plain and simple: yes, humans have made quite an impact on the planet, and you can easily see it from space.