Coming Wirtanen Comet, which can be observed this Sunday at a glance

[KEPY™]

Those who see a comet crossing the night sky can feel excitement, wonder or the feeling that a disaster is looming. In the past, people debated what comets were: an atmospheric phenomenon, a fire in the sky or a star with a tail like a broom.This month we will have the opportunity to check which visual description best fits the perception of each one, because Comet 46P / Wirtanen is scheduled to appear in mid-December and will be perfectly visible.

Thanks to the study that Edmond Halley made in the seventeenth century of what is known as Halley's comet, astronomers discovered that comets are within our solar system. They have very elliptical or elongated orbits around the Sun, which can reach far beyond Pluto.
When comets are far from the Sun they are not special. They are often compared to dirty snowballs. But unlike a rocky asteroid, a comet also has volatile frozen gases, such as methane, carbon monoxide, carbon dioxide and ammonia along with its rock, ice and dust cores.

As this star approaches the Sun, the heat causes the volatile elements to stop being solid and become gases, in a process called sublimation. Thanks to water, methane, carbon dioxide and ammonia, tail is created, the fundamental characteristic of comets, and also a bright cloud, called hair, around its nucleus.

Actually, comets have two different tails: a tail of dust and another of ions or gas. The solar wind and the pressure of the radiation move away the tails of the Sun. The ultraviolet light ionizes part of the material of the tail, creating a charged gas that interacts with the solar wind and ends up pointing directly to the opposite side of the Sun. And the tail of Uncharged powder still follows the orbit of the comet, which makes it more curved.