Discovered by amateur Japanese astronomer Hideo Nishimura, the comet gives off a green glow. Comet Nishimura's trajectory shows it will be slingshotted back into the outer solar system after passing closest to the sun and won’t return for 430 years.

https://www.livescience.com/space/comets/green-comet-nishimura-will-reach-closest-point-to-earth-today-and-it-wont-be-back-for-another-430-years