A rare phenomenon occurred on 2004 June 8: the planet Venus was in transit in front of the Sun. No one alive in the XXth and XXIst centuries had ever seen a transit of Venus: the last transit was in 1882 and was only partially visible in Europe (one of the only existing photography of the solar disk and Venus during the 1882 transit). The observation of the 1882 Venus transit was the most well-known instance to measure the distance between Earth and Sun, that distance being used as the base unit for distances between all heavenly bodies.
On the 2004 Transit of Venus visibility map you can see that since we are at the end of spring there is an area around the North Pole where the Sun never sets, the whole transit being visible with the Sun low on the horizon. Inversely, around the South Pole, there is an area where the Sun never rises, the transit being invisible. You can also notice two zones, one to the south where the Sun will rise and then set and one to the north where the Sun will set and then rise during the transit.