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)

Veterinarian William Guerra Neto (2nd R) and an assistant take measurements of two Amazonian manatees who are being rehabilitated after sustaining injuries from hunting and fishing nets at the Center of Amazonian Manatees at Amana Lake in Maraa, Amazonas state, Brazil, September 21, 2015. (Photo by Bruno Kelly/Reuters)

Golden monkeys play at a conservation base in Shennongjia, central China's Hubei Province, January 26, 2018. The golden monkey conservation base witnessed a snowfall recently. (Photo by Du Huaju/Xinhua/Barcroft Images)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

An invited guest enjoys a private listening experience of a test unit of the Sennheiser HE 1 sound system, which is expected to retail for about S$77370 ($55000), in a hotel suite during the CanJam headphone and personal audio expo in Singapore February 21, 2016. (Photo by Edgar Su/Reuters)

A Hindu woman gives money to an elephant outside the Lord Jagannath temple ahead of the annual Rath Yatra, or chariot procession, in Ahmedabad, India, July 16, 2015. The annual religious procession commemorates a journey by Hindu god Jagannath, his brother Balabhadra and sister Subhadra, in specially made chariots. The annual Rath Yatra is celebrated on July 18. (Photo by Amit Dave/Reuters)

A surfer rides a wave at the snowy beach of Unstad, in Lofoten Island, Arctic Circle, on March 9, 2016. Surfers from all over the world comes to Lofoten island to surf in extrem conditions. Ocean temperature is 6-7 °C, air temperature around 0°C in spite of a weather very unstable. (Photo by Olivier Morin/AFP Photo)

A videographer uses a drone as he takes a video of a model presenting a lingerie creation at the rehearsal for Eve's Temptation collection during China Fashion Week in Beijing, October 26, 2014. (Photo by Kim Kyung-Hoon/Reuters)