WATCH: 'Pulsing orange glow' on Hartlepool horizon baffles experts

AuroraWatch UK, a team of scientists at Lancaster University, said it had received several reports of of a "pulsing orange glow" seen on the horizon last night from Hartlepool at the weekend.

The team studies, and provides an alert service for, the Aurora Borealis, which could be seen last Sunday over the North East. But the team ruled out a return of the Northern Lights as a explanation for the orange glow.

The team said: "As yet, we've not been able to uncover the cause but it wasn't aurora. There's a video of it thanks to Antony Bakuris (@Tant8989) on Twitter."

A number of people responded to a Facebook post on AuroraWatch's page, offering various suggestions for the source of the glow.

Meteor activity, a fire in Teesside, and heavy activity at chemical plants in Wilton were all offered as suggestions.

After seeing our initial story online, reader Ashley Lunn got in touch to say he has spent a long time trying to work out where the orange glow emanates from.

He said: "I've talked to people over the years about this topic and it has been a great debate to have. "I have travelled around Teesside in the past to work out where the source is and it always came back to Redcar ICI / Chemical Works flaring their stacks with & without steam which causes an excessively high flame and thick black smoke. "As it takes several hours to complete this, usually night rolls in and it can be seen glowing ominously in the night sky all around Teesside and some people have speculated as far a field as Sunderland."

Mr Lunn also sent us a link to the stacks flaring during the afternoon, where the flame can be seen climbing very high.

Did you see it? Send us your pictures and/or explanations to [email protected]