The summer solstice has arrived in the UK, marking the official start of astronomical summer across the northern hemisphere. We generally think of it as a whole day - with the longest time of daylight and the shortest period of nocturnal darkness - but the solstice actually happens at an exact time. This year it was at 09:24 BST on 21 June - this moment the northern hemisphere was most tilted towards the Sun. Tap the link in @BBCNews's bio to find out more about the solstice. #Solstice #UK #BBCNews