The planet will come “exceptionally close” to the Earth in the coming weeks, according to Astronomy Ireland.
The society is urging everyone to step outside at 10pm and take a look upwards, while night owls up later will be able to watch the Moon slowly edge closer to Mars as the pair get higher in the sky.
It is already outshining all the stars in the sky and will continue to do so for the next two months.
Chairman of Astronomy Ireland and editor of its magazine David Moore said the planet being so bright is a rare occurrence: "It is already outshining all the stars in the sky and will continue to do so for the next two months.”
"It is very unusual for Mars to be this bright and even more unusual for it to pass very close to the Moon while it is at its most spectacular.
“Astronomy Ireland is urging every Irish person to go outdoors at 10pm on Saturday evening and watch the Moon rise in the East with the planet Mars blazing just to its left. It will be an incredible sight to the naked eye.”
Mr Moore said if viewers wait up until 6am, or decide to rise for an early weekend morning, they can see Mars just on “the top edge of the Moon” before sunrise – something that will not be seen again for over two years in Irish skies.
Most people will have never seen anything like it, and it is a spectacular of nature not to be missed. Get the whole family up.
"In fact, as well as watching at 10pm on Saturday night, we urge everyone to set their alarm for 6am on Sunday morning for the 'main event' when Mars - now at its brightest in two years - is extremely close to the top edge of the Moon,” he added.
“Most people will have never seen anything like it, and it is a spectacular of nature not to be missed. Get the whole family up, especially as the weather forecast for that morning looks promising.”
The next opportunity to see a similar event will be in two years’ time, in December 2022.
