A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

People dance Tuesday, April 28, 2015, in Baltimore. Maryland's governor vowed there would be no repeat of the looting, arson and vandalism that erupted Monday in some of the city's poorest neighborhoods. (Photo by Matt Rourke/AP Photo)

Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)

The Burney, a new streamlined car on the London streets, designed by Sir Denniston Burney who was responsible for the design of the R100 (R 100) airship. The engine is in the rear. (Photo by Topical Press Agency/Getty Images). 15th September 1930

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)

A helicopter is silhouetted by glowing embers as it makes a water drop at the “Old Fire”, which burned in Calabasas, California, U.S., June 4, 2016. (Photo by Gene Blevins/Reuters)

It's taken roughly five months, but a massive iceberg has separated from Antarctica's Pine Island Glacier. According to NASA's Earth Observatory, the estimated size of this iceberg, named B-31, is around 660 square kilometres (33 km long by 20 km wide) – a city-sized block of ice that has slowly migrated away from the continent, and is now floating out to sea. Take a look at some massive icebergs afloat in the oceans. Photo: File photo of an iceberg floating near a harbour in the town of Kulusuk, east Greenland August 1, 2009. (Photo by Bob Strong/Reuters)

The Aurora Borealis (Northern Lights) lights up the sky near the village of Pallas (Muonio region) of Lapland, Finland September 8, 2017. (Photo by Alexander Kuznetsov/Reuters/All About Lapland)