London, Jan 30: Steve Hornsby, a resident of Bournemouth, was left shocked to find small blue sphere in his garden on Thursday afternoon, reports BBC.
He found about a dozen of the balls - which are 3cm in diameter - following a short and fierce hailstorm on Thursday.
Speaking to the BBC, Hornsby said the sky turned an unusual dark yellow colour before the storm began.
The former aircraft engineer said: 'As I walked outside to go to the garage there was an instant hail storm for a few seconds and I thought, "what's that in the grass'?"
Describing the blue spheres, he said: 'It is very jelly-like and it is almost impossible to pick up.
'They have an exterior shell with a softer inner but have no smell, aren't sticky and do not melt.'
Hornsby is keeping the spheres in his fridge while he attempts to find out what they are.
He believes they could be some form of atmospheric pollution.
But according to the BBC, the Met Office says the substance is 'not meteorological'.
Researchers at Bournemouth University have speculated that the small blue balls may be marine invertebrate eggs which could be transferred from the feet of birds.