Rare green comet to be visible soon, then disappears for 1,000 years

A rare, green-glowing comet will make its closest approach to Earth next week — and it won’t return for more than a thousand years.

Comet C/2025 A6 (Lemmon), described by National Geographic as “this year’s brightest comet visible from Earth,” will pass closest to our planet on Tuesday, Oct. 21, coming within about 55 million miles. Scientists say it’s an icy leftover from the early days of the solar system, making this a once-in-a-lifetime sight.

When and where to look

According to National Geographic and Forbes, Comet Lemmon will reach its closest point to Earth on Oct. 21, aligning with a new moon that will make faint celestial objects easier to see.

Skywatchers should look for a soft green glow low in the western sky shortly after sunset, near the constellations Scorpius or Libra.