A reveller walks through the streets in the early hours during traditional May Day celebrations in Oxford, Britain, May 1, 2015. (Photo by Dylan Martinez/Reuters)

A farrier attaches a horse shoe still hot from the furnace at The Household Cavalry Mounted Regiment (HCMR) at Hyde Park Barracks on March 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A girl jumps over a campfire while celebrating Ivan Kupala Night, a traditional Slavic holiday not far from Kiev on July 6, 2013. During the celebration, originating in pagan times, people plait wreaths, jump over fires, and swim naked. (Photo by Sergei Supinsky/AFP Photo)

A man dressed as Hindu goddess Kali, the goddess of power, performs with a burning camphor tablet on his tongue during a religious procession ahead of the “Kumbh Mela”, or Pitcher Festival, in the northern Indian city of Allahabad January 6, 2013. During the festival, hundreds of thousands of Hindus take part in a religious gathering at the banks of the river Ganges. The festival is held every 12 years in different Indian cities. (Photo by Jitendra Prakash/Reuters)

A migratory bird picks her food as army soldiers are reflected in a fountain during rehearsals for the upcoming Republic Day parade at the Raisina hills, the government seat of power, in New Delhi, India, Monday, January 18, 2021. India celebrates Republic Day on Jan. 26, highlighted by a march past by different branches of the military as well as a display of arms and missiles. (Photo by Manish Swarup/AP Photo)

This photo taken on July 19, 2020 shows a security guard looking at his smartphone while water is released from the Three Gorges Dam, a gigantic hydropower project on the Yangtze river, to relieve flood pressure in Yichang, central China's Hubei province. Rising waters across central and eastern China have left over 140 people dead or missing, and floods have affected almost 24 million since the start of July, according to the ministry of emergency management. (Photo by AFP Photo/China Stringer Network)

A resident walks through heavy snowfall in the Kashmiri city, India on November 11, 2019. There have been several fatalities as the winter weather arrives in the region. (Photo by Saqib Majeed/Barcroft Media)

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)