A pair of once-in-a-lifetime comets are rocketing through our skies right now, and it's a rare treat because they won't be back for hundreds of years. The comets, C/2025 A6 (Lemmon) and C/2025 R2 (SWAN),

Two decently bright comets that share a superficial resemblance are gracing our skies right now, in fact: C/2025 A6 (Lemmon) and C/2025 R2 (SWAN). Lemmon has a period (the time it takes to orbit the sun) of about 1,

Short-period comets get close to the sun much more often than their long-period kin, and every time they do, they deplete more of their gas and dust. Consequently, they don’t typically emit as much reflective material per orbit, so they don’t get as bright.

Skywatchers can catch a rare glimpse of Comet Lemmon this month, and it won't be back until around the year 3175. Here's how and when to spot the sparkly green comet.

Comets — objects usually made up of ice, dust, and gases — orbit the sun. NASA says there may be billions of comets within our solar system, coming from either the Kuiper Belt or the Oort Cloud. The Kuiper Belt is found beyond Neptune’s orbit and ...

A rare green Hallowe’en comet will be visible in the night sky over the next few weeks before it vanishes for 1,300 years.

Comet C/2025 R2 (SWAN) is a new visitor from our outer solar system. It may be easier to see as it approaches Earth next week.

Lemmon, which is a rare green comet, can be seen with the naked eye on Oct. 21, according to the Royal Astronomical Society, with peak visibility near Halloween. SWAN may be visible using binoculars or a telescope, according to Starwalk, a real-time astronomical app for stargazing.

NASA and ESA say 3I/ATLAS poses no threat to Earth. We explain its nickel-heavy readings, IAWN’s training drill, and why the Harvard alien claim lacks proof.