Astronotes Armagh Planetarium's Stellar Blog! ... The Northern Lights imaged from Norway in October 2011. ... An aurora is a natural display of light in the sky that can be seen with the unaided eye only at night. In the northern hemisphere it is known as aurora borealis (the Northern Lights). ... The Northern Lights are at their most dazzling from December to March when nights are longest and the sky is darkest. ... In fact Northern Ireland last experienced the northern lights back in 2005! ...