Spot Two Bright Green Comets Illuminating the Night Sky – Here’s How to See Them

Two vibrant green comets are set to illuminate the night sky, captivating observers in the Northern Hemisphere. Comet Lemmon and Comet SWAN are both traveling from the distant reaches of our solar system, potentially originating from the elusive Oort Cloud.

Upcoming Closest Approaches of Comets

Comet Lemmon is expected to make its closest approach to Earth around Tuesday. Meanwhile, Comet SWAN will pass by on Monday, though it is moving away from the sun and is expected to dim over time.

How to Spot the Comets

To view these comets, skygazers should head outdoors just after sunset. Comet Lemmon will be visible low on the northern horizon. Comet SWAN will be located southwest, close to the horizon as well.

Visibility and Equipment

Although spotting two comets at once is rare, it is not unprecedented. Astronomer Carson Fuls noted this through his work at the University of Arizona-based sky survey that identified Comet Lemmon.

Observers may still be able to see both comets with binoculars until the end of the month, though precise brightness predictions remain uncertain, according to Valerie Rapson from the State University of New York at Oneonta.

About the Comets

• Comet Lemmon: Designated as C/2025 A6, this comet was discovered in January during a search for near-Earth asteroids.
• Comet SWAN: Known as C/2025 R2, this comet was identified in September by an amateur astronomer using NASA and ESA spacecraft images.

Both comets exhibit a green hue due to the gases emitted from their surfaces. They will likely appear as gray, fuzzy patches from Earth.

Historical Context

This year, a different green comet unfortunately disintegrated as it approached the sun, disappointing hopes for a spectacular display. In contrast, the notable approach of Comet Tsuchinshan-Atlas in 2024 and previous visible comets like Neowise in 2020 highlight the occasional wonders of our night sky.

As these notable comets grace our skies, they remind us of the frozen remnants from the solar system’s birth billions of years ago, heating up and releasing their luminous tails as they draw nearer to the sun.