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)

In this September 14, 2017 photo, young women pose for a photo inside their squatter building that used to house the Brazilian Institute of Geography and Statistics (IBGE) in the Mangueira slum of Rio de Janeiro, Brazil. Many lower-middle class Brazilians who gained ground during the boom years have since slid back closer to the poverty line. (Photo by Felipe Dana/AP Photo)

A migrant labourer brushes his teeth in front of a scrapped helicopter model in Mumbai, India, April 13, 2016. (Photo by Danish Siddiqui/Reuters)

Family members pose for photos near lava flowing from Pacaya Volcano near El Patrocinio village in San Vicente Pacaya, Guatemala, Friday, April 16, 2021. (Photo by Moises Castillo/AP Photo)

The feet of a Filipino penitent is nailed to a wooden cross during Good Friday rituals on April 3, 2015 at Cutud, Pampanga province, northern Philippines. Several Filipino devotees had themselves nailed to crosses Friday to remember Jesus Christ's suffering and death, an annual rite frowned upon by church leaders in this predominantly Roman Catholic country. (Photo by Aaron Favila/AP Photo)

A lady wearing a mask feeds pigeons in St James' Park, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 5, 2020. (Photo by Henry Nicholls/Reuters)

A Hindu holy man looks at a decoration on the ghats of the river Saryu as part of preparations for the groundbreaking ceremony of a temple to the Hindu god Ram in Ayodhya, in the Indian state of Uttar Pradesh, Monday, August 3, 2020. As Hindus prepare to celebrate the groundbreaking of a long-awaited temple at a disputed ground in northern India, Muslims say they have no firm plans yet to build a new mosque at an alternative site they were granted to replace the one torn down by Hindu hard-liners decades ago. (Photo by Rajesh Kumar Singh/AP Photo)