Kilcullen Diary: St Patrick's festival show at Dunshane

DID YOU KNOW?

There are three different scientific phases of twilight. Civil twilight is the first, named because the sky is still bright enough for people to go about normal 'daytime' activities — technically this is from when the sun is just below the horizon to when it's six degrees lower. Nautical twilight is when the sun is between six and 12 degrees below the horizon, named because it is the time when stars become visible and sailors used them to fix their position. Astronomical twilight is when the sun is 12 to 18 degrees below the horizon and the sky finally appears black, but to astronomers is not quite so. After that is true scientific night.