Comet C/2017 K2 (PANSTARRS)

C/2017 K2 (PanSTARRS) is an Oort cloud comet with an inbound hyperbolic orbit, discovered in May 2017 at a distance beyond the orbit of Saturn when it was 16 AU (2.4 billion km) from the Sun. It had been in the constellation of Draco from July 2007 until August 2020. As of June 2022, the estimated distance of the comet from the Sun is ±5000 km. The comet is record breaking because it is already becoming active at such a distance. Only comet Hale–Bopp produced such a show from that distance with a similar nucleus. However, this comet will not be as visible as Hale–Bopp was in 1997 in part because it does not come nearly as close to the Sun.

Comet C/2017 K2 (PANSTARRS)
June 25, 2022
GT102 - ASI533MC - 50x180 sec exposures

On its way to perihelion, C/2017 K2 is currently shining at about mag 7. Missing is the typical greenish glow of a comet's halo that comes from diatomic carbon (C2), a simple yet unstable form of elementary carbon. C/2017 K2 is too far from the sun for the reaction to occur.