If you wish to see two comets, your greatest probability shall be early this week. After a 12 months with none comets vivid sufficient to be seen with out specialist gear, two — Comet C/2025 A6 (Lemmon) and Comet C/2025 R2 (SWAN) — have come alongside without delay.
Comet Lemmon could look extra like a lime than its title suggests, however on Tuesday (Oct. 21), the dusty snowball from the outer photo voltaic system will attain its closest level to Earth and more than likely shine at its brightest. It is now reached magnitude 4.5, in line with SpaceWeather.com — about the identical brightness as spring’s Beehive Cluster (M44) and solely somewhat dimmer than the Andromeda galaxy (M31).
Observe the form of stars within the Large Dipper’s deal with to “arc to Arcturus”; the comet shall be about two-thirds of the way in which there. On Tuesday, it is going to be somewhat larger. For Comet SWAN, search for the Summer season Triangle of vivid stars — Vega, Deneb and Altair — within the southwest. You may discover Comet SWAN about midway between Altair and the horizon.
Useful finder charts and sky maps for each comets can be found at The Sky Dwell, In-The-Sky.org and Stellarium, in addition to in night-sky apps similar to Sky Information, Sky Tonight and SkySafari 7 Professional. If you wish to attempt photographing the comets, our information has you lined.
The 2 comets are on vastly completely different journeys. Comet Lemmon will get to inside 56 million miles (89 million kilometers) of Earth Tuesday, in line with The Sky Dwell, on its technique to looping across the solar Nov. 8 throughout its 1,350-year orbit of the solar. (Nevertheless, Jupiter sapped a few of Comet Lemmon’s orbital power, shortening its interval by almost 200 years, in line with Star Stroll, so it is not going to return till 3179.)
Comet SWAN is a long-period comet, orbiting the solar each 20,000 years, in line with Universe Immediately, and on Monday, it is going to be 24 million miles (39 million km) away because it exits the internal photo voltaic system. That is a few quarter the space between Earth and the solar.
