Overview
- Fresh guidance for Oct. 15 says Lemmon will be visible both after sunset and before sunrise, with the best viewing about 90 minutes after dusk or before dawn for mid‑northern latitudes.
- Recent measurements put the comet near magnitude +5.2, which is near the naked‑eye threshold under very dark skies, so binoculars are still recommended.
- Closest approach comes around Oct. 21 at roughly 55.4 million miles from Earth during the new moon, and astronomers say it poses no danger.
- Find the comet beneath the Big Dipper in Ursa Major/Canes Venatici, appearing low in the northwest after dusk and in the northeast before dawn as it brightens nightly.
- Discovered by the Mount Lemmon Survey in January, the comet’s orbital period of about 1,350 years is expected to shorten to roughly 1,150 years after this passage, while a second comet, SWAN, is also brightening in the southwest after sunset.