A resident carries a gas canister as an ash cloud hovers above during an eruption of Mount Sinabung volcano at Tiga Serangkai village in Karo Regency, North Sumatra province, Indonesia June 24, 2015. More than 10,000 people from 12 villages, who are living around the slopes of Mount Sinabung, left their homes and moved to refugee camps, local media reported. (Photo by Reuters/Beawiharta)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

People appear dangling as a large-scale installation art piece by Leandro Erlich, named “Dalston House”, in London, England. Part of the “Beyond Barbican” summer series of events, the interactive installation is a full facade of a late nineteenth-century Victorian terraced house built on the ground with a large mirror above it to reflect people as to appear dangling from the structure. (Photo by Dan Dennison)

The Cage of Death at Crocosaurus Cove in Darwin City, Australia. The Cage of Death starts out above the water where the two tourists in it can see the huge crocodile below before the cage is lowered into the pen. The tourists are then inches from the 16-foot-long Saltwater crocodile as it greedily snaps its jaws over meaty treats that are being dangled right in front of the cage. (Photo by Crocosaurus Cove/Media Drum World/Profimedia)

An incredible view of Thunderstorms light up the insides of clouds near a beautiful sky line. This is truly heavenly weather as pictures taken from an airplane cockpit reveal what pilots see from above. It looks like at cruising altitude the weather really hots up, with the flight deck revealing some amazing scenes. Thunderstorms light up the insides of clouds, lightening streaks across the sky like cracks in a windscreen, the northern lights sweep uninterrupted across the sky and the galaxy stretches on forever. The pictures were captured by senior first officer Christiaan van Heijst, a 33-year-old from the Netherlands, and his friend Daan Krans. (Photo by Christiaan van Heijst/Daan Krans/Caters News Agency)

A photographer has captured these amazing rainbow-like images of stars high above the skies of Colorado. Stargazer Matt Payne, from Oregon, loves the evening skies so much, he has devoted hours to shooting the marvels of the Milky Way. The 35-year-old has to meticulously plan his work, taking into account weather, terrain, season and even the cycle of the moon to get the perfect snap. (Photo by Matt Payne/Caters News)

“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)

Breitling Wingwalker Freya Paterson, from Liverpool, UK, flies above Kuwait City's iconic Water Towers with pilots David Barrell and Martyn Carrington, on March 6, 2014. The team loop and roll up to 160 mph enduring G-forces of 4-5g. Crowds are expected to line the Kuwaiti coastline to catch a glimpse of the Wingwalking team on Saturday, March 8, 2014, to mark the opening of the first dedicated boutique in the city for the prestigious watch brand. (Photo by Katsuhiko Tokunaga/Breitling)