C/1999 S4

C/1999 S4 is a long -period comet, which was discovered on 27 September 1999 by the LINEAR project. The comet had its closest approach to Earth on 22 July 2000 at a distance of 0.3724 AU. The diameter of the core of C/1999 S4 was estimated to be about 0.9 km. Before the comet broke up, the core erosion rate was approximately 1 cm per day. To the 5th July 2000, the comet was brighter and some fragments detached from the core. Around July 20, he again increased its brightness and then broke up almost completely.