Rare comet offers southern skies a glimpse of the distant past
A celestial visitor, C/2025 R3 PanSTARRS, is poised to grace southern skies over the next fortnight, providing a remarkably rare opportunity to witness a comet last seen 170,000 years ago.
A journey from the oort cloud
The comet, originating from the vast Oort Cloud – a reservoir of icy remnants at the very edge of our solar system – has embarked on a long and solitary journey, recently swinging around the sun and now appearing in the southern hemisphere. Astronomer Josh Aoraki, based at Te Whatu Stardome in Auckland, New Zealand, notes that while its brightness isn’t immediately striking, it’s surprisingly amenable to photographic capture, a welcome bonus for amateur and professional observers alike.
“It’s not a bright object to see with the naked eye, but it’s definitely a decently easy one to photograph, which is always nice,” Aoraki commented. Scientists have recently identified 27 potential new planets orbiting a pair of distant stars, a testament to the ongoing exploration of our vast universe, though this comet’s brief appearance offers a dramatically different spectacle.
Viewers in New Zealand, Australia, South Africa, and across the Pacific should aim to capture the comet’s fleeting beauty as soon as possible, as its brightness will steadily diminish over the coming two weeks. Optimal viewing conditions involve locating a clear, unobstructed westward horizon shortly after sunset – the comet will remain low in the sky during this hour.
Expect to observe a blue-green coma – a temporary cloud of gas surrounding the comet’s nucleus – and a smudgy, ephemeral tail, resembling a fuzzy meteor streaking across the darkness. The trajectory, however, remains uncertain; the comet's mass loss as it orbits the sun could dramatically alter its course, potentially sending it spiraling out of the solar system entirely.
“It’s really hard to predict the trajectory of them, because as they do go around the sun, they’re losing mass, and that can change the path,” Aoraki explained. “So it could be back in that amount of time, but it also could be ejected from the solar system entirely.”