View of colourful rock formations at the Zhangye Danxia Landform Geological Park in Gansu Province, China. The Zhangye Danxia Landform Geological Park is 40km from Zhangye city. The park spans more than 400 square kilometers in Gansu. The unusual terrain is the result of red sandstone and mineral deposits carved over the years by natural forces. (Photo by ImagineChina/The Grosby Group)

“The scientists behind NASA's $2.5 billion Curiosity rover mission on Mars on Tuesday explained the nature of a tiny, gleaming "flower" embedded in Red Planet rock, and revealed where they'll be using the SUV-sized robot's drill for the first time”. – Alan Boyle via NBCNews.com

Photo: Scientists say that a “Martian flower”, seen here in an image from the Curiosity rover's Mars Hand Lens Imager, is a 2-millimeter-wide grain or pebble that's embedded in the surrounding rock. Another, darker-colored mineral grain can be seen above and to the left. (Photo by NASA)

Afghan boys ride on donkey cart transporting plastic bottles for recycling, on the outskirts of Kabul, Afghanistan, on 16 September 2020. Nearly 19 years after the fall of the Taliban regime and the United States invasion, the Afghan government and insurgents on 12 September, began peace negotiations in Doha. (Photo by Hedayatullah Amid/EPA/EFE)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)

The barren landscapes of the south-western US provided inspiration for photographer David Clapp. He visited Nevada, New Mexico, Utah and Arizona as part of his project on other-worldy locations, with surreal results. Here: An infrared image at dusk of strange clay rock formations in Ah-Shi-Sle-Pah Wilderness in Farmington, New Mexico. (Photo by David Clapp/Barcroft Images)

A National Bolivarian Police officer rescues a man who was being attacked by protesters, who then threw rocks at them, during a protest demanding food a few blocks from Miraflores presidential palace in Caracas, Venezuela, Thursday, June 2, 2016. Venezuela is seeing rising frustration with widespread food shortages and triple-digit inflation. (Photo by Fernando Llano/AP Photo)

Tree trunks and rocks are set up to support a leaning wall of Li Yonghua's damaged cave house in an area where land is sinking next to a coal mine, in Helin village of Xiaoyi, China's Shanxi province, August 2, 2016. (Photo by Jason Lee/Reuters)

Mutant vehicles on the Playa are seen as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. September 3, 2016. (Photo by Jim Urquhart/Reuters)