Tonight there could be a meteor shower known as the Tau Herculids which emanate from the break-up of a well known periodic comet named 73P/Schwassmann-Wachmann, or “SW3", which was discovered in 1930 and orbited the Sun every 5.4 years. It broke up into nearly 70 pieces before its 2006 pass and Earth will pass through the trail of debris in the early hours of tomorrow morning. At this time of year the sky doesn't get dark for very long so the viewing window is short. There is a possibility that it could be the most impressive meteor shower ever witnessed. But it's also possible we will see nothing at all.