Two comets, C/2025 A4 (Lemmon) and C/2025 R2 (SWAN), are about to reach their closest approach to Earth and you can watch the action unfold live online.
“So far, living in the Northern hemisphere, I could admire C/2025 A6 Lemmon only, but C/2025 R2 SWAN is quickly joining the show and we are ready to amaze every astronomy lover with our live feed!”
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 soar even closer, at roughly 24 million miles (39 million km).
Comet C/2025 R2 (SWAN) was discovered in September 2025 by the Solar and Heliospheric Observatory’s SWAN instrument.
Editor’s note: If you capture a photo of Comet Lemmon or Comet SWAN and would like to share it with Space.com, send your images and comments to spacephotos@space.com.
You can watch the action live online as two comets, C/2025 A4 (Lemmon) and C/2025 R2 (SWAN), approach Earth at their closest point.
October will see a special livestream from astronomer Gianluca Masi and his Virtual Telescope Project. Twenty starting at 1:30 p.m. A. EDT (1730 GMT) to observe both comets as they approach Earth closely, which puts them in a prime observational position.
“I have only been able to admire C/2025 A6 Lemmon thus far because I live in the Northern Hemisphere.
However, C/2025 R2 SWAN will soon be joining the show, and we are prepared to astound everyone.
astronomy enthusiast with our live feed!” Masi wrote in an email to Space . com.
If the weather permits, you can watch the cosmic show live on the Virtual Telescope Project’s website or YouTube channel, or on Space . com.
Infrequent double-comet encounter.
A unique cosmic treat is when two right comets are visible in the sky at roughly the same time. Comet Lemmon (C/2025 A6) will fly almost 56 million miles (90 million kilometers) away from Earth during the event, and Comet Swan (C/2025 R2) will fly even closer, at about 24 million miles (39 million kilometers). Both should reach their brightest point in October. Oct. 20 and Oct. 21.
As it flies through the inner solar system, Comet C/2025 A6 (Lemmon), which was discovered in January 2025, has been gradually getting brighter. After sunset, Lemmon can be seen in the western evening sky through binoculars or a small telescope. As it moves north, it gradually gets higher each night.
The SWAN instrument of the Solar and Heliospheric Observatory made the discovery of Comet C/2025 R2 (SWAN) in September 2025. The best time to see it is before dawn, when the comet is still moving away from the sun and is low on the eastern horizon.
See our guides on the best binoculars and beginner-friendly telescopes, as well as our guide on taking comet photos, if you want to see the comets for yourself. Additionally, for more celestial highlights this month, check out our night sky guide.
Note from the editor: If you want to share a photo you took of Comet Lemmon or Comet SWAN with Space . com, send it to spacephotos@space . com along with your comments.
