People will have a good opportunity to see a newly discovered comet this week in what astronomers are calling a "once-in-a-lifetime" opportunity. 

Comet Nishimura was discovered in August by Japanese astrophotographer Hideo Nishimura - who it was also named after.

The newly discovered comet is already visible Tuesday is set to present people with their best chance to see it with the naked eye.

When is the best time to see Comet Nishimura?

The best time to see the comet was in the hour after sunset and the hour before dawn by looking east-north-east, towards the crescent moon and Venus.

What is known about Comet Nishimura

Scientists are still trying to estimate Nishimura’s size but Professor Brad Gibson, director of the E A Milne Centre for Astrophysics at the University of Hull, believes it could range from a few hundred metres to potentially a mile or two in diameter.

He said it is thought the comet could be responsible for an annual meteor shower named the Sigma-Hydrids, which takes place in December every year.

According to Prof Gibson, there is no danger of Comet Nishimura colliding with Earth as astronomers have carefully charted its orbit and speed of travel.

How are comets formed?

Prof Gibson explained comets are “chunks of ice and rock” left over from the formation of the solar system nearly five billion years ago.

As they pass closer to the sun it heats the comet, liberating an icy gas which gives them their distinctive tail.

He said 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.