One of the most studied comets in history will be favorably passing by the Earth in the next few days. Aside from Halley’s Comet, Comet Encke is the most famous and richest in history of all of those mysterious icy wanderers that wend their way among the planets. While Encke is not expected to be visible to the unaided eye, it will be an interesting target through binoculars and small telescopes, for those experienced enough to find it.Encke is the comet with the shortest orbital period known – taking about 3.3 years to complete one revolution around the Sun. It does not approach giant Jupiter as closely as do some other periodic comets. So unlike other comets, whose orbits get gravitationally adjusted by Jupiter, Encke’s orbit has remained more or less stable for hundreds of years. This year, Encke’s Comet will reach perihelion -- its closest point to the Sun -- on Dec. 29. It will be closer to Earth, however, on Monday Nov. 17, providing the best viewing opportunity in more than six decades.Whenever perihelion falls in November, December or January, the comet becomes very favorably placed for skywatchers in the Northern Hemisphere. Conversely, when perihelion is in May, June or July, the comet is difficult or impossible to see north of the equator, but can be well seen from the Southern Hemisphere.

The history of Encke’s comet stretches back more than two centuries. This will be the 59th observed return of this object since it was first seen as a fuzzy object on the edge of naked-eye visibility by the Parisian comet hunter Pierre Méchain on Jan. 17, 1786. Because three revolutions of this comet so nearly equal ten years, it retraces almost the same path across the sky at such intervals. True to this 10-year interval, the comet was not seen again until Caroline Herschel accidentally ran across it on Nov. 7, 1795. Comet Encke was then about 24 million miles from Earth, and her brother William reported that he could even glimpse it without any optical aid.

View: Full Article | Source: space.com