On, Comet

When was the last time you saw a comet without having to use a telescope? Best guess, five to 10 years ago, because that's how often that kind of thing happens. So you know you won't get to see another one for another five to 10 years, because there are two in the sky this month: http://www.jpl.nasa.gov/news/news.php?release=2013-088&cid=release_2013-088