Members of the Royal Navy respond to a simulated fire in a Vanguard-class submarine control room training facility at Clyde naval base in Faslane, Scotland on January 21, 2016. (Photo by Photograph: Danny Lawson/PA Wire)
The sun rises beside St Mary's Lighthouse in Whitley Bay, Tyne and Wear, as the unseasonably cool weather continues on Thursday, April 28, 2016. (Photo by Owen Humphreys/PA Wire)
Handout photo dated March 20, 2015 issued by Chester Zoo of lemurs looking at the eclipse over Chester Zoo. (Photo by Steve Rawlins/PA Wire/Chester Zoo)
Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)
Undated David Yarrow handout photo of a gorilla as the self-taught wildlife photographer promotes his book, Encounter. (Photo by David Yarrow/Clearview/PA Wire)
Vocalist Laila Skovmand, a musician with Danish company Between Music, plays underwater in a tank during a rehearsal ahead of their UK premiere concert Aquasonic at the Tramway in Glasgow on Ocrober 25, 2017. (Photo by Robert Perry/PA Images)
Let the fun begin. Revellers carry their belongings as they arrive at Worthy Farm in Somerset for the Glastonbury Festival, Britain, June 22, 2016. Around 180,000 are expected to attend. (Photo by Ben Birchall/PA Wire)