The Southern Cross seen at 23:00 22 Tuesday April 22 (tonight).Today is the 50th anniversary of Earth Day. Of course, I'm late to this. A number of astronomers have suggested that we use today (now tonight) to look up t they sky and esitimate the amount of light pollution that is affecting our world to mark Earth Day.Globe at Night run Light pollution observing campaigns, all you have to do is go out when the sky is fully dark, look south and count the stars you can see in the Southern Cross, then fill out a report.It's easy to do, fills in our knowledge of light pollution and connect us with the sky. Hopefully you are not clouded out like I am. .