Comet McNaught has become the brightest comet in 30 years, according to the International Comet Quarterly at the Harvard-Smithsonian Center for Astrophysics.Tonight (Wednesday, Jan. 10) may be the best chance for Northern Hemisphere viewers to spot it.But this comet remains a challenge. You need a very clear view of a very flat horizon and good sky conditions. Look for it moments after sunset.At magnitude -2, McNaught is brighter than was Hale-Bopp in 1995.