Comet C/2025 E1 (Lemmon) Poised to Become 2025’s Brightest Comet, Visible This Fall
Skywatchers are anticipating a spectacular celestial display this fall as Comet C/2025 E1 (Lemmon) rapidly brightens adn becomes perhaps visible to the naked eye. Initially dismissed as a faint object, the comet has surprised astronomers with a dramatic increase in activity as reappearing in August, and is now predicted to reach peak visibility in the coming weeks. NASA reports the comet will reach its closest point to the Sun, known as perihelion, on November 8, when it will be approximately 79 million kilometers from our star.
Discovered on January 3, 2025, Comet Lemmon was initially estimated to be too dim for even amateur telescopes. Though, a close encounter with Jupiter on April 16, 2025 – passing within 348.5 million kilometers - altered its orbit,shortening its period from 1,350 years to an estimated 1,154 years and boosting its potential brightness. This gravitational “cosmic brake” has set the stage for a potentially stunning viewing opportunity.
Currently, the comet has an estimated magnitude of +6.1, nearing the threshold of naked-eye visibility. As it approaches the Sun, its coma – the diffuse cloud surrounding its nucleus – is expanding, and a bluish tail composed of ionized gases is beginning to form. If the comet increases its dust emission, its tail could become even brighter, reflecting more sunlight.
While precise viewing conditions will depend on light pollution and atmospheric clarity, astronomers suggest the best time to observe Comet Lemmon will be throughout October and November 2025. The comet’s increasing brightness and favorable position relative to the Sun and Earth are expected to make it a prominent feature in the autumn sky. NASA continues to monitor the comet’s progress, stating that if it maintains its current trajectory, it could become the most prominent comet of the year.
