In 1997, Hale-Bopp made it's closest approach to Earth. Remember how crazy people got? Everyone remembers the Heavens Gate suicides. The hysteria and expectation that was encouraged then by the frauds, charlatans, chicken-littles, and merely misguided, indirectly led to the deaths of those people. One could say that they were inclined to take their own lives anyway, but the atmosphere created certainly was feeding their fantasy.
A local doomsday cult, led by the Little Pebble even tacked onto Hale-Bopp.
As we all know, Hale-Bopp was a spectacular comet, but it came and went. Right now it's on it's way out of the Solar System, and wont be back for 2,364 years. Go here for an update into Hale-Bopp.
Strangely, or maybe not so strangely, there are still nitwits out there who think that Hale-Bopp had an artificial object orbiting it (a spaceship??). Notable among this is the "Millennium Group". Another notable group, and just as guilty, is the group known as the "Farsight Institute", though they no longer have any reference to their spectacular failure on their webpage, and even though I have enquired as to their current position on Hale-Bopp, they have not answered.