A great comet is a comet that becomes exceptionally bright and easily observable to the naked eye. There is no official definition; the term is often attached to comets such as Halley's Comet, which,
Comet McNaught as the Great Comet of 2007
The Great Comet of 1680 over Rotterdam as painted by Lieve Verschuier
Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing roughly every 74–79 years. It last appeared in the inner parts of the Solar Syst
Great comet
…that becomes exceptionally bright and easily observable to the naked eye. There is no official definition; the term is often attached to comets such as Halley's Comet, which, during certain appearances, are bright enough to be noticed by casual observers not looking for them and become well known outside the astronomical…
Halley's Comet photographed by William Liller from Easter Island on 8 March 1986
"I must entreat you to procure for me of Mr Flamsteed what he has observed of the Comett of 1682 particularly in the month of September, for I am more and more confirmed that we have seen that Comett now three times, since yͤ Yeare 1531, he will not deny it you, though I know he will me." —Excerpt of Halley's letter to Newton about comet's orbits (September 28, 1695)
Jamaican polymath Francis Williams (portrait attributed to William Williams, c. 1760). The only contemporary illustration of an astronomer detecting the comet's return.
Orionid meteor originating from Halley's Comet streaking the sky below the Milky Way and to the right of Venus