Comet ISON (Nov. 15)Today is the day Comet ISON (captured above in a Nov. 15 photo by the TRAPPIST telescope) has its close encounter with the Sun, swinging within 1.2 million km of our world’s favourite star and then beginning its long outward journey to the distant reaches of the solar system.

As far as sun-grazers go, ISON is pretty big. But scientists still aren’t sure it will survive its brush with the Sun. If it does get torn apart by tidal forces, we’ve seen the last of it. If it survives, though, it will emerge from the Sun’s glare and be visible to the naked eye again on the weekend.

According to this CBC report, the best viewing will be about a half an hour before sunrise. Then as the comet’s distance from the Sun increases, it will become visible for longer periods at night, potentially putting on a pretty good show.

Through analysis of its trajectory scientists have determined that ISON is not a periodic comet. That means that once it disappears from view it will continue to move away from the Sun, eventually leaving the solar system and never returning.