Later this year, the world could be in for a once-in-a-century astronomical treat: Comet ISON may become as bright as a full moon and be a daytime comet. Yes, on a clear day, you should be able to go outside and see ISON hanging in a blue abyss (just as Comet McNaught did in 2007, pictured above).
The comet, designated C/2012 S1, was discovered last year by the Russian International Scientific Optical Network (ISON - hence the comet's name) and it quickly became apparent that it could be the "Comet of the Century." If it lives up to the hype, we'll be in for a very exciting nighttime and daytime show this November. However, astronomers urge caution: comets don't always behave as expected.
It appears that ISON is a pristine comet freshly ejected from the Oort Cloud (a hypothetical population of comets that surround the solar system around one light-year from the sun), so it could be a pretty robust object packed with primordial ice and dust that was created during the solar system's formative years. If this is the case, it could survive its death-defying journey past the sun, creating a wonderful tail of ice, gas and dust as it does so.