When celebrating Earth, I’m always reminded of two things: 1) We’re all citizens of this planet, so let us stop calling other humans “illegal.” And 2) Without Earth, there’s no us — let’s do all we can to keep it clean and take better care of it. Astronomer Carl Sagan’s beautiful famous words on Earth, Pale Blue Dot, are a good reminder of our place in the vast Universe. Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering,…