Keith’s note: I have been living with the image in my mind of the Pioneer plaques and Voyager Golden Records heading across the outer solar system and into interstellar space for half a century. To me, that was the most Carl Sagan – of Carl Sagan – ideas. All these years later – despite its Disco era origins – it transcends time well – which is exactly what you want a message to the inhabitants of another solar system to embody. Well, NASA just did something as cool – and in some ways even cooler. More at An Astrobiology Droid Asks And Answers ‘How Many Ways Can You Say Water’?