EarthSky News - March 13 - Second Friday the 13th of 2015

March 13 Second Friday the 13th of 2015 2015 has three Friday the 13ths.  What are the odds? Here’s why 2015 has three Friday the 13ths. What are star trails, and how can I capture them? As Earth spins under the sky, the stars appear to move.  When a camera captures that movement, that's called a star trail.  An astrophotographer explains how he does it. Use Big Dipper to locate Hunting Dogs The Hunting Dogs are a separate constellation: tiny Canes Venatici. This date in science: Uranus discovered, completely by accident William Herschel noticed while surveying stars that one object moved apart from the star background.  It was the first planet discovered since ancient times. Visit the EarthSky store Help support EarthSky, and get tips and tools for astronomy. Friday FAQ:  Why beware the Ides of March? You can thank William Shakespeare. TODAY'S IMAGE What are star trails, and how can I capture them? Photo by Ken Christison.