If you miss comet Lemmon this time around you'll have to wait 1,150 years to see it again.

Comet C/2025 A6 (Lemmon) was discovered in January of this year and will reach its closest approach to Earth on October 21. It is expected to be visible to the naked eye from dark sky locations, especially in the evening after sunset in the Northern Hemisphere by mid-October. The comet will pass perihelion (closest to the Sun) on November 8.
And it's green!