A girl eats a watermelon slice while at a school building where Syrians – displaced from the area of Ras al-Ain by the Turkish offensive on the northeast – are staying in the city of Hasakah, on June 30, 2020. (Photo by Delil Souleiman/AFP Photo)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.

Vinaya Vijay, right, and Vijay Parthasarathy wade through water at Badwater Basin, Thursday, February 22, 2024, in Death Valley National Park, Calif. The basin, normally a salt flat, has filled from rain over the past few months. (Photo by John Locher/AP Photo)

Moroccans gather to celebrate Morocco's win over Spain in a World Cup soccer match played in Qatar, in Rabat, Morocco, Tuesday, December 6, 2022. (Photo by Mosa'ab Elshamy/AP Photo)

Mariana Sousa, student of the Ballet Paraisopolis, warms up during a rehearse in Paraisopolis favela, outskirts of Sao Paulo, Brazil on August 27, 2020, amid the new coronavirus COVID-19 pandemic. The 200 ballet students of Paraisopolis, the second largest favela in Sao Paulo, restarted rehearsals after five months with a coreography about a police operation that put their community in mourning last year. (Photo by Nelson Almeida/AFP Photo)