“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)

Sharafkhaneh port and lake Urmia. Masoud Ghadiri (Iran). The summer Milky Way is very prominent in this photo. On the galaxy zone, Saturn is located besides the Lagoon nebula. On the right of the horizon, you can see the extreme light pollution of Urmia, which is caused by ever-increasing city development. (Photo by Masoud Ghadiri/National Maritime Museum)

Best portfolio winner. Roseate Spoonbill, Platalea ajaja, by Petr Bambousek, Czech Republic. (Photo by Petr Bambousek/2018 Bird Photographer of the Year)

Pashtan Wagner, a Blue Oriental Cat participates in the GCCF Supreme Cat Show at National Exhibition Centre on October 28, 2017 in Birmingham, England. (Photo by Shirlaine Forrest/WireImage)

The shortlist for the coveted Bird Photographer of the Year awards has been announced by Nature Photographers and the British Trust for Ornithology. Here: Red-billed oxpecker on an impala, Kruger National Park, South Africa. (Photo by Edmund Aylmer/BPOTY/Cover Images/The Guardian)

A selection of prizewinning images from the Take a View 2016 photography awards. Here: Finding Gold, taken in Wast Water in Cumbria, which won the Great Britain #OMGB “Home of Amazing Moments” award. (Photo by Mark Gilligan/PA Wire)

The sun rises between Sgurr nan Gillean and Knight’s Peak, Black Cuillin, Isle of Skye. (Photo by Adrian Trendall/Mountain Photo of the Year)

The competition is run by Royal Observatory Greenwich sponsored by Insight Investment and in association with BBC Sky at Night Magazine. This year astrophotographers from 91 countries sent in more than 4,200 spectacular entries. Here: The Milky Way rises above an isolated lighthouse in Tasmania. Shot by James Stone of Australia. (Photo by James Stone/Astronomy Photographer of the Year 2018)