Look on it
Two comets, C/2025 A4 (Lemmon) and C/2025 R2 (SWAN), are about to make their closest approach to Earth and you can watch the action unfold live online.
Astronomer Gianluca Masi and his virtual telescope project will host a special livestream on October 20 from 1:30 p.m. EDT (5:30 p.m. GMT) to watch the two comets move closer to Earth, making them well-positioned for observations.
“So far, living in the Northern Hemisphere, I have only been able to admire the C/2025 A6 Lemmon,
but the C/2025 R2 SWAN is quickly joining the show and we are ready to surprise everyone.
astronomy enthusiast with our live stream!” Masi told Space.com in an email.
You can watch the cosmic spectacle live here on Space.com, courtesy of the Virtual Telescope Project or on the the project website Or YouTube channelif time permits.
Rare double comet encounter
Having two straight comets visible in the sky at around the same time is a rare cosmic treat. During the event, Comet Lemmon (C/2025 A6) will pass about 56 million miles (90 million kilometers) from Earth, while Comet Swan (C/2025 R2) will come even closer, about 24 million miles (39 million km). Both are expected to reach their maximum brightness between October 20 and 21.
Comet C/2025 A6 (Lemmon) was discovered in January 2025 and has continued to brighten as it passes through the interior. solar system. Lemmon is visible in a pair of binoculars or small telescopes in the western evening sky after sunset, slowly climbing higher each night as it moves north.
Comet C/2025 R2 (SWAN) was discovered in September 2025 by the Solar and heliospheric observatoryThe SWAN instrument. It is best observed in the pre-dawn sky, when the comet appears low on the eastern horizon as it continues its journey away from the sun.
If you’re hoping to spot comets yourself, check out our guides on best binoculars And best telescopes for beginnersas well as our how to photograph comets guide. And don’t forget to explore our night sky guide to more celestial highlights this month.
Editor’s note: If you take a photo of Comet Lemmon or Comet SWAN and want to share it with Space.com, send your images and comments to spacephotos@space.com.