Top 10 travel destinations for The brightest long-period comets in history tend to be ones that have made close approaches to the Sun. Some, known as sungrazers, come perilously close to the Sun at perihelion. From their population come many of the brightest and most spectacular comets in history. One example of a sungrazer is Comet Ikeya-Seki, which has a period of years and in October came as close as AU to the Sun by comparison, the Moon is . AU from Earth. Some sungrazers clearly belong to the same family. For example, the Kreutz Sungrazing Group consists of comets with high-inclination and – to ,-year orbits. Top 10 travel destinations 2016.