UFOs? 'Strange light' seen in sky across Ireland caused by US rocket launch

Is it a bird? A plane? The strange light is likely to have been caused by a SpaceX rocket. Picture: Carlow Weather/X

While there will be plenty of aliens trick-or-treating for Halloween, stargazers were left to wonder about UFOs after a "strange light" was spotted across the sky in Ireland on Wednesday. 

Multiple reports of the light moving in the sky were made across the country, including in counties Cork, Dublin, Tipperary, and Galway, at approximately 6.30pm.

It was described as having a “halo”, and of moving at “slightly varying speed” by some on social media platform X.

While social media users had many theories on what the “strange light” could be, it was revealed that it was likely caused by a SpaceX Falcon 9 rocket, which launched from Florida on Wednesday.

SpaceX, owned by tech billionaire and world’s richest man Elon Musk, operate a series of low-earth orbit satellites for Starlink, an international satellite telecommunications service.

The bright light was said to be caused by the process of excess rocket fuel being ejected and freezing, then reflecting light back to earth. The path and the trajectory of the rocket matches the reported sightings over Ireland, experts said.

Space commentator Leo Enright said ejecting fuel from rockets was a normal occurrence.

“If they keep the fuel in the rocket there is a danger that it will explode and shower debris, so it is a standard practice now for space companies to vent fuel,” Mr Enright told the PA news agency.

“It does look spectacular if it happens at a particular time of the day, when the viewer down on earth is in darkness or near darkness and the rocket stage is in light.” 

He said the view is often “more spectacular” than was seen on Wednesday night because the ejected fuel can be seen rotating.

“When the stage is rotating you get a truly extraordinary spiral effect that makes it look like a galaxy.” 

Asked why the spectacle had not grabbed attention in Ireland previously, he said: “The lighting, that’s the reason. It’s all to do with lighting, and also honestly seeing anything from Ireland is a challenge.

“So I’m sure it’s happened in the sky and we just couldn’t see it because of cloud.” 

Mr Enright also said there was an irony to the sighting because astronomers from around the world are meeting in Westport, Co Mayo, this week to discuss the clutter effect of satellites causing congestion in the skies.

“Astronomers are extremely annoyed about the effect this is having on their ability to look at the stars,” he said. “These damn satellites are getting in the way and the problem is getting worse and worse.” 

He said that some months ago “a big chunk” from a SpaceX rocket fell “harmlessly” in a field in Poland.

“The reason why Ireland is quite vulnerable (to space debris) is that we are, generally speaking, at the highest point on the map of the launch trajectory of the rockets out of Cape Canaveral (in Florida).

“So it’s never been an issue up to now because rockets were only launching once a week, maybe, now they’re launching virtually once a day out of Cape Canaveral with the SpaceX rockets.” AirNav Ireland has been contacted for comment.

Meanwhile, Carlow Weather's Alan O’Reilly tracked the light across Wednesday evening and told RTÉ's Morning Ireland that it was moving quite quickly and was "very confusing". 

He added that he had reports from people of the light being visible right across the country. 

SpaceX launched 29 Starlink internet satellites into orbit from Florida on Wednesday.

SpaceX is a private American aerospace company that was founded by Elon Musk in 2002. In 2025 alone, SpaceX launched over 2,500 Starlink satellites into orbit.

The satellites are part of a broadband constellation, with 8,000 satellites currently in orbit.