Comet C/2017 K2 (PanSTARRS) is approaching the perihelion point – the closest approach to the Sun – which will occur on December 20. It sails through the skies of the southern hemisphere of the planet, remaining a good object for observation with a telescope.
In this picture, its greenish coma and whitish dust tail are clearly visible, stretching almost half a degree in the upper left part of the picture. Another comet, 73P/Schwassman–Wachman 3, has also entered the star-rich field of view in the constellation Scorpio, it is visible about one degree below and to the right of comet PanSTARRS.
The Schwassman-Wachman 3 comet is more familiar to us. A periodic comet orbits in an elliptical orbit for 5.4 years, moving away to the orbit of Jupiter and approaching the Sun to a distance approximately equal to the radius of the Earth’s orbit.
