Comets SWAN and Lemmon approach Earth

Rally around this double galactic advantage.

After a year devoid of comets visible to the naked eye, two celestial entities – C/2025 A4 (Lemmon) and C/2025 R2 (SWAN) – will grace our skies around the same time.

Lemon will reach its closest approach to Earth on Tuesday, October 21, when it will reach a distance of about 56 million miles from Earth. According to life science.

Meanwhile, fellow comet SWAN (C/2025 R2), known for its bright bluish-green color, will pass at a closer distance of about 24 million miles. Both are expected to be at their best between October 20 and 21 respectively, with Lemon recording a brightness three times that of its fellow interstellar ice globe.

How do you see a green comet?

For this reason, despite SWAN’s proximity, stargazers will need binoculars to see its flyby while Lemmon will be visible with the naked eye in very dark skies.

When do you see comet lemon?

The latter, which was discovered in January 2025 and has been steadily brightening during its journey through the solar system, will be most visible an hour and a half after sunset on Tuesday, October 21.

It will appear in the northwestern sky, near the Big Dipper and the bright star Polaris, and close to the horizon.

Meanwhile, comet C/2025 R2 (SWAN), discovered in September 2025 by the Solar and Heliospheric Observatory’s SWAN instrument, will be at its brightest at about the same time but a day earlier.

Sky watchers should look for the summer triangle of bright stars — Vega, Deneb, and Altair — in the southwest. SWAN will be located between Altair and the horizon.

However, don’t worry if you can’t catch these celestial hailstones directly.

Astronomer Gianluca Masi and his Virtual Telescope Project will host a Special live broadcast on October 20 starting at 1:30 p.m. so people can capture this cosmic doubleheader from afar.

“So far, living in the Northern Hemisphere, I can only admire C/2025 A6 Lemmon, but C/2025 R2 SWAN is quickly joining the show and we’re ready to wow every astronomy fan with our live broadcast!” Massey said Space.com website In an email message.

We recommend watching it in some form as Lemmon won’t make a visible comeback tour again until the year 3175, making this a once-in-a-lifetime event.