People in Cork were left perplexed after spotting a 'low flying aircraft' travelling in an unusual pattern on Monday night.
Locals in areas outside the city as far apart as Ballincollig and Watergrasshill reported the "strange" sighting late at night.
The "mystery" aircraft was observed by one woman as circling a local park for an hour.
The woman, whose name is Sarah, contacted Neil Prenderville on Cork's RedFM station.
She said: “Hi Neil. Just wondering if anyone knows what the low flying aircraft over Beech Park in Ballincollig was last night? It was circling the park for over an hour around 10PM. Very strange.”
Following the query, Cork natives were quick to share a simple explanation for the plane's activities.
One person said: "I live in Watergrasshill and yesterday we had the Tellus Geological survey plane flying at low altitude throughout the day. This maybe it . It finished in this area around 5pm."
Another added: "I believe it is a survey aircraft - I think Cork Airport have confirmed a survey aircraft is working around Cork."
It was confirmed yesterday that a low-flying survey aircraft would be present over Cork in the coming days.
The Tellus survey will continue its flying season this week across Cork, south Limerick and west Waterford, with the current survey block being 40% complete.
This survey is a national programme to gather geochemical and geophysical data across Ireland.
Tellus is undertaken by Geological Survey Ireland and examines the chemical and physical properties of our soil, rocks and water.
It involves two types of surveying, airborne geophysical surveying using a low flying aircraft, and ground-based geochemical surveying of soil, stream water and stream sediment.
Following the completion of the Tellus airborne survey across south-central Ireland, the aircraft is now moving to County Cork and neighbouring parts of south County Limerick, and west Waterford.
The survey, which commenced in July, will continue until September.
