Sandstone sculpted by water and wind erosion is seen in a slot canyon, one of hundreds that surround Lake Powell near Page, Arizona, May 26, 2015. Lake Powell on the Colorado River provides water for Nevada, Arizona and California. A severe drought in recent years, combined with withdrawals that many believe are not sustainable, has reduced its levels to only about 42 percent of its capacity. (Photo by Rick Wilking/Reuters)

China has recently relaxed its one child policy that was used to control a burgeoning population. A couple has their wedding photo taken in an old quarter of Beijing on May 24, 2016. (Photo by Michael Robinson Chavez/The Washington Post)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

A few Catholic devotees manage to get closer to either kiss or rub with towels the cross of the image of the Black Nazarene as they take part in a raucous procession to celebrate its feast day in Manila, Philippines, Saturday, January 9, 2016. As in the past, the annual procession attracts thousands of devotees with scores being injured and saw the deployment of hundreds of police and soldiers. (Photo by Bullit Marquez/AP Photo)

Revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. Germany is celebrating its traditional carnival with tight security after assaults on women during New Year's Eve celebrations across the country. (Photo by Kai Pfaffenbach/Reuters)

The “EMIEW3” robot (R) demonstrates communicating with a visitor during a press preview in Tokyo on April 8, 2016. Japanese electronics giant Hitachi unveiled its humanoid customer service and guidance robot “EMIEW3” and “remote brain” robotics IT platform. (Photo by Toshifumi Kitamura/AFP Photo)

These spectacular images of the universe are the finalists in the 2016 CWAS “David Malin” awards. The annual competition, which celebrates the best astronomy images taken by Australian photographers, is part of AstroFest 2016. The winners will be announced on 16 July. An associated exhibition opens the following day at the CSIRO Parkes Observatory visitors centre, and a second exhibition will also travel to selected venues around Australia. Here: Mars and its Rival Antares and the Rho Ophiuchi cloud complex. (Photo by Phil Hart/CWAS/The Guardian)

In this Wednesday, July 13, 2016, handout image provided by Solar Impulse, the Solar Impulse 2 flying over the pyramids, Egypt Cairo. The experimental solar-powered airplane has arrived in Egypt as part of its global voyage. (Photo by Jean Revillard, Rezo via the AP Photo)