I woke up recently to find the following structures on my lawn; they resemble bubbles, but are formed from ice (we had a moderate frost overnight). There were eight of these 'bubbles' on my lawn and one smashed one on the adjacent path. They were only present in my garden, and nowhere else.
What processes could have allowed these 'bubbles' to form in this shape?
'Bubbles' on grass: Damaged 'bubble' This was found on the paving slab and was not touched: