Toe, The writes: Hartley 2 circles the sun every 6.46 years. The comet comes within 17.7 million kilometers of Earth, or about 45 times the Earth-moon distance, on October 20. From dark skies in the Northern Hemisphere, the comet should be visible to the naked eye as a fuzzy object in the constellation Auriga. Binoculars or a small telescope may be required to see Hartley 2 from urban areas. The comet, discovered in 1986, makes its closest approach to the sun on October 28. Observers in the Southern Hemisphere should have a good view of the comet in late November as it heads away from Earth. On November 4, a NASA spacecraft will fly within 700km of the object.