riverat1 writes "Now visible in the morning sky, comet ISON will swing around the Sun on November 28. ISON will pass 730,000 km above the surface of the Sun at closest approach (Mercury's perihelion distance is 46 million km). If it survives its near brush with the Sun it could provide a spectacular sky show from December into January. This NASA timeline shows that ISON will be the most observed comet ever as instruments ranging from a balloon carried telescope to the Hubble Space Telescope to the STEREO satellites will be brought into play. Lowell Observatory astronomer Matthew Knight lays out three possibilities for ISON: spontaneous disintegration before it gets to the Sun (less than 1% chance); disintegration as it rounds the Sun; or survival. If it survives, its closest approach to Earth will be on December 26 at about 1/3 of an AU."