It's sharing time.  Here's a cool space mashup map, titled "If extraterrestrial civilizations are monitoring our TV broadcasts, then this is what they are currently watching."

It's a plot of nearby stars, with lines indicating which TV show signals are just now reaching them.  It's from Abstruse Goose, which is a new fav for me.  Plus they have a free eBook of the first 100 comics.  And their website is minimalist.  Enjoy!

Conceptually, it's an elegant mashup.  Take a star map, which has distances to nearby stars in light-years (distance light travels in one year).  Since radio waves are EM waves, same as visible light, they travel (ta da!) one light year in one year.  So if a star is 3 light years away, it's getting signals we sent out 3 years ago.  By converting distances to past transmission dates, presto, we get the map!

Alex, the daytime astronomer

The Daytime Astronomer, Tues&Fri here, via RSS feed, and twitter @skyday