Apollo 9 Command/Service Modules (CSM) nicknamed “Gumdrop” and Lunar Module (LM), nicknamed “Spider” are shown docked together as Command Module pilot David R. Scott stands in the open hatch. Astronaut Russell L. Schweickart, Lunar Module pilot, took this photograph of Scott during his EVA as he stood on the porch outside the Lunar Module. Apollo 9 was an Earth orbital mission designed to test docking procedures between the CSM and LM as well as test fly the Lunar Module in the relative safe confines of Earth orbit. (Photo by NASA)

The 26th annual National Geographic Traveler Photo Contest is now accepting submissions. Official categories include: “Travel Portraits”, “Outdoor Scenes”, “Sense of Place” and “Spontaneous Moments”. The contest is accepting entries until June 30. Photo: “Forest lights”. Aurora Borealis over the forest of the Pyhae Luosto National Park, Finland. (Photo and caption by Nicholas Roemmelt/National Geographic Traveler Photo Contest)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

A man stands on a mountain summit as he looks over the Inntal valley in the western Austrian village of Gnadenwald, Austria on July 18, 2017. (Photo by Dominic Ebenbichler/Reuters)

Festival-goers enjoy on Shipyard Island, the venue of the 24th Sziget (Island) Festival in Northern Budapest, Hungary, 12 August 2016. The festival is one of the biggest cultural events of Europe presenting art exhibitions, theatrical and circus performances and music concerts. (Photo by Polyák Attila/Origo.hu)

Inside the new Digital Art Museum in Tokyo, Japan on June 21, 2018. These incredible photos show what it looks like inside a groundbreaking new digital art museum in Japan. A trip to the Mori Building Digital Art Museum: teamLab Borderless in Tokyo, which opened last week, can make you feel like they you are dreaming and aims to fully immerse visitors in the art. Spanning a spacious 10,000 square metres, 520 computers and 470 high-tech projectors create the illusion that the visitor is wandering through rice fields, following shoals of fish or even bouncing on a galaxy of planets. (Photo by South West News Service)

A Sikh devotee carries on over-sized religious sword during a religious procession to celebrate the birth anniversary of the first Sikh Guru or master, Sri Guru Nanak Dev Ji, the founder of Sikhism in Amritsar, India, 05 November 2014. The birth anniversary of Guru Nanak Dev Ji will be observed on 06 November. (Photo by Raminder Pal Singh/EPA)

Chinese-American actress Bai Ling attends “The Key” screening at The Real Experimental Film Festival at Laemmle's Music Hall on November 21, 2014 in Beverly Hills, California. (Photo by Barry King/WireImage)