The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

Luling, Louisiana, US. New evidence contradicts previous claims of the relative safety of glyphosate, the world’s most widely used herbicide, which is manufactured here. It is often used in conjunction with seeds that have been genetically modified to tolerate its application, meaning that anyone consuming these crops is eating a genetically modified plant, and whatever residue of the pesticide that remains. (Photo by J. Henry Fair/Industrial Scars/Papadakis Publisher)

With less than a week before Election Day, a Halloween skeleton holds a vote sign outside a home in Falls Church, Virginia, October 29, 2020. (Photo by Kevin Lamarque/Reuters)

Motorcycle enthusiast Gilbert Delos Reyes rides with his pet dog Bogie, in Kawit, Cavite, Philippines, November 26, 2020. (Photo by Eloisa Lopez/Reuters)

Young women pose for photos in a Christmas-themed tunnel lit-up with decorations outside a shopping mall in Bangkok on December 4, 2020. (Photo by Mladen Antonov/AFP Photo)

An Iranian girl walks past a mural with Iran's national flag in a street in Tehran, Iran, 03 December 2020. Iranian president Rouhani said that his government does not agree with the parliament's draft bill to quit the nuclear deal, to reduce nuclear commitment and to increase nuclear activities. The development comes after the assassination of Iranian nuclear scientist Mohsen Fakhrizadeh earlier this week. (Photo by Abedin Taherkenareh/EPA/EFE/Rex Features/Shutterstock)

Emma Raducanu of Great Britain takes a selfie after victory over Stephanie Voegele of Switzerland in the first round of the women's singles of the US Open at the USTA Billie Jean King National Tennis Center on August 31, 2021 in New York City. (Photo by Rex Features/Shutterstock)

Emma Raducanu of Great Britain hits a return to Belinda Bencic of Switzerland during their quarterfinals round match on the tenth day of the US Open Tennis Championships the USTA National Tennis Center in Flushing Meadows, New York, USA, 08 September 2021. The US Open runs from 30 August through 12 September. (Photo by Justin Lane/EPA/EFE)