A man carrying an axe walks past a house marked with bullet holes in Gyallesu district after recent clashes between Shi'ites and the army in Zaria, Kaduna state, Nigeria, February 3, 2016. Sectarian tensions are rising in Nigeria's Muslim north, where hundreds of Shi'ites were killed in clashes with the army in the town of Zaria in December, according to Shi'ites and rights groups. Following the clashes, bulldozers sent by the state levelled Shi'ite shrines, a cemetery and offices in the deeply divided town. The region is already grappling with an insurgency waged by the jihadist Boko Haram group. (Photo by Afolabi Sotunde/Reuters)

A girl rides a donkey as another walks by at the Shawqaba camp for internally displaced people who were forced to leave their villages by the war in Yemen's northwestern province of Hajjah March 12, 2016. In northwest Yemen, one of the poorest countries in the Middle East, about 400 families uprooted by the war have been stuck in the Shawqaba camp in Hajjah province for the past year. Residents live in poorly built huts that protect them neither from summer heat nor winter cold in a camp that lacks the most basic services. (Photo by Abduljabbar Zeyad/Reuters)

Military helicopters fly in formation above a billboard with a picture of China's late Chairman Mao Zedong during a training session for the upcoming parade marking the 70th anniversary of the end of World War Two, on the outskirts of Beijing, July 2, 2015. Troops from Russia and Mongolia will march together with Chinese forces in a parade in Beijing in September to commemorate the end of World War Two, the government and state media said on Thursday, confirming the first two foreign participants. (Photo by Jason Lee/Reuters)

A photographer is using a unique method to show the shift from day to night across famous cities in spectacular images. Daniel Marker-Moors' take on time-lapse photography – which he calls time slice – sees the photographer snap image after image, before combining them to create beautiful, vibrant works. His images usually focus on a point in the day with the most dramatic change in light, such as sunrise or sunset. Marker-Moors, from Los Angeles, begins by shooting hundreds and sometimes thousands of images from the same spot. Here: Chicago – 35 photographs, 15 minutes. (Photo by Daniel Marker-Moors/Caters News)

Every year National Parks Week gives visitors a chance to celebrate the incredible woodland spaces around the UK. This year the National Parks Week runs from 28 July – 3 August and there are 10 national parks across England to explore. Each one has created a special event to celebrate the National Parks Week, from picnics and treasure hunt in the park to cycle rides, safari or outdoor art exhibition. (Photo by Diana Jarvis/VisitEngland)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)

“The Space Launch System, or SLS, is a Shuttle-Derived heavy launch vehicle being designed by NASA, following the cancellation of the Constellation Program, to replace the Space Shuttle after its retirement. The NASA Authorization Act of 2010 envisions the transformation of the Ares I and Ares V vehicle designs into a single launch vehicle usable for both crew and cargo. It is to be upgraded over time with more powerful versions. The proposed SLS is visually similar to the legacy Saturn V booster and in particular the proposed, two-stage, Saturn INT-20”. – Wikipedia

Photo: In this illustration provided by NASA, the design for a new space rocket system, the Space Launch System, is seen. NASA's new rocket design will reportedly cost about $35 billion and be ready to for test launch in 2017. According to NASA, the rocket will be used to carry Orion Multi-Purpose Crew Vehicle as well as cargo and science experiments to earth's orbit, as a backup for the space station and possibly destinations beyond that. (Illustration by NASA via Getty Images)

Chinelos (traditional costumed dancers) perform in front of San Andres Ocotlan church as part of continuing festivities to welcome the new year in Calimaya, Mexico on January 4, 2016. (Photo by Arturo Hernandez/Demotix/Corbis)