First of all, in case you didn’t know, according to a few sources, today is not just Valentine’s day, but also: Impotence Day, Condom day, Singles Awareness Day, Ferris Wheel Day, Congenital Heart Disease Day, and Pet Theft Awareness Day. And on to the Astronomy!  A classic favourite would be the Heart Nebula. Located 7,500 light years away in the constellation Cassiopeia, this heart-shaped HII emission nebula is located along the plane of the Milky Way galaxy.  HII regions like this one are used to probe the massive star formation in a galaxy.  This is because massive O and B...