A newly-discovered comet is making its closest approach to Earth today, and could be visible from the UK with the naked eye tonight.
Comet Nishimura – officially known as C/2023 P1 – was only discovered in August. It orbits the Sun just once every 437 years, making seeing it a true once in a lifetime opportunity.
The comet may not even survive much longer, as there is a chance it burns up when it passes close – in space terms – to the Sun later this week.
Nishimura will be roughly 20 million miles from the Sun – more than four times closer than Earth – and pass inside the orbit of Mercury.
How can I see Comet Nishimura?
The best times to see the comet are in the hour after sunset and the hour before dawn. It will reach its closest point to Earth on Tuesday 12 September – when sunrise in London will be around 6.30am – and its closest point to the Sun on 17 September.
You should look in the direction east-north-east, near the crescent Moon and Venus, which is appearing brightly in the sky. It should appear low in the sky, within the constellation Leo.
Long exposure images of the comet show it having a bright green head and blue-grey tail. It should be visible with a telescope or binoculars, but it may also be possible to see it with the naked eye, as it has been increasing in brightness, though likely only as a faint smudge.
Nasa said in a blog post: “Will Comet Nishimura become visible to the unaided eye? Given the unpredictability of comets, no one can say for sure, but it currently seems like a good bet.
“As the comet dives toward the Sun, it will surely continue to intensify and possibly become a naked-eye object in early September. A problem is that the comet will also be angularly near the Sun, so it will only be possible to see it near sunset or sunrise. The comet will get so close to the Sun – inside the orbit of planet Mercury – that its nucleus may break up.”
Professor Brad Gibson, an astrophysicist at the University of Hull, said: “The comet takes 500 years to orbit the solar system, Earth takes one year, and the outer planets can take many decades.
“Halley’s Comet, which caused much interest during its last nearby visit to Earth in 1986, takes 76 years to orbit the solar system.
“So, to say this is a once-in-a-lifetime opportunity to see Nishimura isn’t an exaggeration.”
How was Comet Nishimura discovered?
Nishimura was discovered by Japanese amateur astronomer Hideo Nishimura on 12 August, 2023 during 30-second exposures with a standard digital camera.
It was in Gemini and shining at around 10th magnitude when discovered, but has since brightened and moved into Leo.
Nicolas Biver, an astrophysicist at the Paris Observatory, said it is very rare a comet is discovered so soon before it makes its closest approach to Earth.
“Most are discovered months, even years before they pass closest to the Sun,” he told the AFP news agency.
