Shimmering clearest blue and stretching as far as the eye can see, this is one of Iceland's famed crystal ice caves. The giant solid waves look frozen in time but they are slowly moving along as part of the Vatnajokull Glacier – which stretches across eight per cent of the island. The images were captured in February 2014 by British photographer Rob Lott, 49. Photo: A wide view of Rob Lott in the crystal ice cave in the Vatnajokull Glacier, Iceland. (Photo by Rob Lott/Barcroft Media)

Macro or Micro? Scientists’ pictures baffle our sense of scale. It began when Stephen Young, a geography professor at Salem State University in Massachusetts, tricked his biologist colleague Paul Kelly into thinking a satellite image was one of his electron microscope scans. Can you guess whether they are close-up or very far away? (Photo by Paul Kelly)

Children play in an outdoor shower as a soldier takes part in a surprise operation in the Manguinhos slum in Rio de Janeiro, Brazil, Thursday, January 18, 2018. Troops have been sent to Rio due to the increase of the violence, and in an attempt to help restore order, but so far have had little impact. The operation on Thursday took place three weeks ahead of Carnival, when thousands of tourists are expected to arrive in the city. (Photo by Leo Correa/AP Photo)

The face of a graduating student is displayed on a tablet attached to a robot during a “cyber graduation” ceremony at a school on May 22, 2020 in Taguig, Metro Manila, Philippines. Robots represented some 179 graduating students of the Senator Rene Cayetano Science and Technology High School during a graduation ceremony that was streamed online, as mass gatherings remain prohibited in the country under the Philippine government's lockdown to curb the spread of the coronavirus. The robots were developed by alumni of the school's robotics club, which used tablets to display the faces of the graduating students as they “marched” on stage to receive their diplomas. The Philippines' Department of Health has so far reported 13,434 cases of the coronavirus in the country, with at least 846 recorded fatalities. (Photo by Ezra Acayan/Getty Images)

A girl stands with arms outstretched at North Narrabeen on January 27, 2024 in Sydney, Australia. Around 30 indigenous children from Brewarrina, Weilmoringle, and Goodooga in the far North West NSW travelled to Sydney to participate in the program. The initiative is part of the Bush to Beach programme, which now in its 19th year, gives indigenous children a unique opportunity to learn and explore Sydney's beach culture. (Photo by Jenny Evans/Getty Images)

Astronaut Edward H. White II, pilot for the Gemini-Titan 4 (GT-4) spaceflight, floats in the zero-gravity of space during the third revolution of the GT-4 spacecraft on June 3, 1965. White wears a specially designed spacesuit. His face is shaded by a gold-plated visor to protect him from unfiltered rays of the sun. In his right hand he carries a Hand-Held Self-Maneuvering Unit (HHSMU) that gives him control over his movements in space. White also wears an emergency oxygen chest pack; and he carries a camera mounted on the HHSMU for taking pictures of the sky, Earth and the GT-4 spacecraft. He is secured to the spacecraft by a 25-feet umbilical line and a 23-feet tether line. Both lines are wrapped together in gold tape to form one cord. Astronaut James A. McDivitt, command pilot, remained inside the spacecraft during the extravehicular activity (EVA). Astronaut White died in the Apollo/Saturn 204 fire at Cape Kennedy on January 27, 1967. (Photo by NASA)

The First U.S. Spacewalk – Gemini 4 Ed White made the United States' first spacewalk on June 3, 1965 during the Gemini 4 mission. The extra-vehicular activity (EVA) started at 19:45 UT (3:45 p.m. EDT) on the third orbit when White opened his hatch and used the hand-held manuevering oxygen-jet gun to push himself out of the capsule. (Photo by NASA)

People gather as a crowd of sea lions lay on floating docks at Pier 39 in San Francisco, California May 4, 2015. Hundreds of sea lions began hauling out on the docks following the Loma Prieta earthquake of 1989, and face no natural predators at the pier. (Photo by Robert Galbraith/Reuters)