Not all comets have their orbits calculated so it is impossible to say.
2012
The next notable comet scheduled to pass by Earth is Comet Leonard, which is expected to be visible in December 2021. It will be the brightest comet of the year and should be observable with binoculars or a small telescope from dark sky locations. Keep an eye out for updates from astronomers as the date approaches for the best viewing opportunities.
Isaac Newton
The next visible comet that is expected to be visible to the naked eye is Comet Leonard in late 2021.
Halley's comet is not predicted to hit Earth in the foreseeable future. The next time it will be visible from Earth is in 2061.
never we will survive
comet 99947 (zorton 47) is coming in 2016
The current prediction is for some time in 2061.
Some time in 2061 i think
It can be seen every 75-76 years. The next predicted perihelion of Halley's Comet will be 28 July 2061.
It's unclear what you mean by "hades comet." If you are referring to a comet named Hades, there is no specific comet with that name. If you meant Halley's Comet, it will next be visible from Earth in 2061.
Comets have a stream of gas and dust coming off them.