The comet is currently 150 million miles from the sun, but as it falls deeper and deeper into the sun's gravitational well, ISON will likely brighten as icy volatiles from the comet's nucleus heat up and erupt into space. The addition of gas and dust should cause the comet's coma to increase in size.
But will this be the comet of the century? Many astronomers are becoming increasingly skeptical of that fact.
ANALYSIS: Comet ISON Offers Doomsday Deja Vu
Comet ISON was discovered in Sept. 2012 and its orbit initially caused some excitement. The object appears to be a "virgin" comet from the hypothesized Oort Cloud that is thought to contain billions of icy objects that intermittently drop into the inner solar system as comets. The pristine nature of Comet ISON led many to believe that once heated by the sun's heat, it could erupt, making this a historic event. Although notable, ISON appears to be holding its own and may not erupt into the "daytime" comet we were hoping for.
This "sungrazer" will come within 724,000 miles of the sun on Nov. 28, so it will be interesting to see whether the comet's nucleus survives its fiery descent.