Sky gazers are in for a treat tonight with one of "the most spectacular events" of the year visible to the public.
Astronomy Ireland has said an extremely bright "star" next to the moon will be Jupiter - the largest planet in the solar system.
The event will be visible from all over the world.
Astronomy Ireland has a special event to give the public a close up view of both the moon and Jupiter through their telescopes.
It is taking place at Astronomy Ireland's Headquarters in Rosemount Business Park, Blanchardstown.
Editor of Astronomy Ireland magazine David Moore said: "It is really only a line-of-sight effect with Jupiter being 2,000 times further away than the moon, but to the general public it will look like the two brightest objects in the night sky will be beside one another in the most impressive display the moon can ever put on with another celestial object.
"This is definitely an event for your 'bucket list', seeing the two brightest objects in the night sky closer than you will ever see them again in your life."
He said that the moon is always stunning in a telescope, "with thousands of craters peppering its surface and vast lava plains and huge mountains all visible in the giant telescopes.
"It's an amazing sight that never fails to amaze me even after years of seeing it in a large telescope."
He said that those who stay until after 10pm "will even get to see the Great Red Spot on Jupiter which is the biggest storm in the solar system, bigger than Earth, and has been 'blowing' with 500 km/h winds for over 300 years".