June 15/16th 03.14 BST. Could this display get any brighter?, despite being allocated the brightest value of 5 on the scale of 1 to 5, I felt that this one surpassed many of the stunning type 5 displays I have seen in previous years. A 5 value is obtained when the display is so bright that it catches the attention of members of the public and illuminates objects facing the display. This one had already been doing that for the last few hours, and as the Sun rose min by min so did the intensity of the display. For this reason I think a new level of 6 should be applied to the brightness scale to separate the typical type 5 monster displays from those which seem brighter still. If a display casts obvious shadows, or illuminates objects in front of it, then it's already similar to, or brighter than, the magnitude of planet Venus which is mag -5, and considering that NLCs are not a point source, but rather spread out like the coma of a huge comet, it stands to reason that NLCs must be considerably brighter than Venus and comparable with the quarter Moon phases. The last quarter Moon was in the sky (see previous images) and it looked a sorry sight in comparison to the NLC display.
