Read, Watch or Listen

Two bright green comets—Lemmon and SWAN—are gracing Northern Hemisphere evenings, with Lemmon nearing Earth around Tuesday and SWAN’s flyby on Monday as it fades while heading away from the sun. Experts call the dual display rare but not unprecedented. Look just after sunset: Lemmon low in the north, SWAN low to the southwest. Both may remain visible with binoculars through month’s end, though their brightness is uncertain. The comets likely hail from the solar system’s distant reaches and appear green from outgassing, yet from Earth they resemble gray, fuzzy patches.

Prepared by Olivia Bennett and reviewed by editorial team.