The newly discovered Comet Nishimura is zooming through the skies, heading for its closest point to Earth.
Astronomy buffs have a “rare and exciting opportunity” to see a comet with the naked eye in a “once-in-a-lifetime” experience.
“Comets are a fossil left over from the formation of our solar system,” Brad Gibson, director of the E A Milne Centre for Astrophysics at the University of Hull, told The National.
“They are a pristine representation of what it was like billions of years ago when our planet formed. They are also beautiful and incredibly powerful.”
How to watch
Nishimura will be visible in the night sky as it reaches its closest position to Earth right before dawn on Tuesday, September 12.
To view the comet, look low in the sky and near the sun.
It will be visible for 30-60 minutes before sunrise and after sunset.
Depending on local conditions, you should be able to see it with the naked eye but binoculars or a telescope will help.
“It can already be seen but it will be 78 million miles from Earth on September 12 and that should be the best chance to see it with the naked eye,” Mr Gibson said.
“On average, people have the chance to see such a naked eye comet once a decade – this is a rare and exciting opportunity.”
When will it return?
It was only discovered three weeks and may never be seen again.
The comet has a 520-year orbit around the sun and there is no guarantee that it will survive.
Mr Gibson said Nishimura will pass closest to the sun on September 17, when it will be only 43 million kilometres away, and it is possible the comet may not survive the encounter.
The comet is named after Japanese astrophotographer Hideo Nishimura, who recorded it when he was taking long-exposure photographs of the sky with a digital camera on August 11.
Why is it special?
“To say this is a once-in-a-lifetime opportunity to see Nishimura isn't an exaggeration,” Mr Gibson said.
“The comet takes 520 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.
Scientists are trying to estimate Nishimura's size but Mr Gibson believes it could range from a few hundred metres to potentially a kilometre in diameter.
He said it is thought the comet could be responsible for an annual meteor shower called the Sigma-Hydrids, which takes place in December every year.
What is a comet?
Comets are chunks of ice and rock, and are remnants from the formation of the solar system nearly five billion years ago.
As comets pass closer to the sun, the heat liberates an icy gas that gives them their distinctive tail.
Tiny particles of dust and rock from comets are freed by the sun as a comet passes nearby and each year the Earth passes through this debris, leading to meteor showers.