A bright comet could be visible in skies across the globe over the coming days for the first time in 160,000 years. Nasa said the future brightness of a comet is "notoriously hard" to predict, but that Comet C/2024 G3 (Atlas) could remain bright enough to be seen by the naked eye. On Monday, the comet was at perihelion, the point at which it is closest to the Sun, which influences how bright it appears. Experts say it could be visible from Monday night. While the exact locations for possible visibility are unknown, experts believe the comet, which could shine as bright as Venus, may be best observed from the southern hemisphere. The comet was spotted last year by Nasa's Asteroid Terrestrial-impact Last Alert System. Dr Shyam Balaji, a researcher in astroparticle physics and cosmology at King's College London, said "current orbital calculations indicate it will pass about 8.3 million miles from the Sun", which classifies it as a "sun-skirting" comet. The university described the comet as a once-in-160,000-years event. Dr Balaji said opportunities to spot the comet may occur "in the days around perihelion, depending on local conditions and the comet's behaviour". "As with all comets, its visibility and brightness can be unpredictable," he added. Balaji said people who live in the southern hemisphere — where the comet is predicted to be best observed from — should "look toward the eastern horizon before sunrise, [and] after perihelion, try the western horizon after sunset." But Balaji added that while it is expected to be "quite bright", predictions on comet brightness are "notoriously uncertain", with many ending up fainter than initially predicted. For the northern hemisphere — including the UK — viewing may be challenging do to the comet's relativity to the Sun. You can check with BBC Weather online to see if the skies are clear enough for a possible sighting where you are. Balaji advised people wanting to spot the comet to find a location away from light pollution and use a pair of binoculars or a small telescope. He warned observers to be cautious around sunrise and sunset, and said to track the comet's position to find where it may appear in the sky. Meanwhile, astronomers have been following the comet's path. On Saturday, Nasa astronaut Don Pettit, shared a photograph on social media of the comet taken from the International Space Station. "It is totally amazing to see a comet from orbit. Atlas C2024-G3 is paying us a visit," he wrote. — BBC
