Is is a bird? Is it a plane? Or is it a visitor from another world?
Those in Edinburgh think the latter, as it has been named the top city in the UK for UFO sightings.
A survey found that 18 per cent of residents in the Scottish capital claim to have spotted something otherworldly in the sky.
London and Leicester came second and third on the list, with 14 and 12 per cent respectively, according to the research commissioned by the National Geographic.
In it, 2,000 UK adults were asked if they believed they had seen a UFO whizzing above their hometown, as well as their opinions on extraterrestrial life.
Just under half of the survey participants said they believe in the existence of aliens, while ten per cent claimed they have witnessed something ‘unusual’.
Moreover, 59 per cent of those people believe their odd encounter was of alien origin.
It comes after scientists from the University of California said that aliens could make contact with Earth as soon as 2029.
Nick Pope, a former UFO investigator for the Ministry of Defence, said: ‘UFOs are big news now, and a lot of people are reporting – and sometimes filming – extraordinary things.
‘While many people are convinced these sightings involve alien life, most cases turn out to be misidentifications.
‘The chances are that there’s intelligent life elsewhere in the universe, and even though the vast distances make direct contact a challenge, encountering an alien civilisation would be the biggest story in human history.’
Just under a third of those surveyed believe that humankind will at some point make contact with aliens, and about one in three want the Ministry of Defence’s UFO Project to be restarted.
The division was axed in 2009 after nearly 60 years of official research and investigations.
In 2016, Mr Pope said that of the 12,000 sightings that the programme investigated, approximately five per cent remained unexplained.
The former investigator said in 1980 the department were alerted to a UFO close to the Bentwaters and Woodbridge airbases.
The team later concluded that radiation levels at the site had been ‘significantly higher than the average background’.
Indeed, last year, NASA announced it was to conduct its first ever study into unidentified aerial phenomena (UAP).
These are events in the sky that cannot be absolutely identified as aircraft or known natural phenomena.
Leicester, which came second on the list, is only just over an hour’s drive away from Bonsall in Derbyshire.
The unsuspecting village was named the ‘UFO H๏τspot’ of the UK last month, as it has been central to numerous sightings over the years.
Some claim that even NASA has shown interest in the area, after one local spotter recorded a mysterious flying object in the night sky.
UFO-believers in Leicester also most often claim they have found actual evidence or had an experience proving the existence of aliens.
Respondents to the recent survey were asked about why they thought aliens may contact Earth, and 41 per cent said they believe they would be here to carry out scientific study.
Another 21 per cent fear they would be harvesting the planet for raw materials, and 11 per cent wouldn’t be surprised to see the entire human race taken into slavery.
In November, a group of scientists from the University of St Andrews said they will be putting together a plan for what to do if we encounter aliens here on Earth.
On their website, they write that humans are ‘entirely unprepared’ for contact with intelligent life from other worlds.
The National Geographic survey was commissioned ahead of its new documentary series ‘UFO’s: Investigating the Unknown’, which airs on May 2 at 8pm.