General view of the screens in Hyde Park to showing the Royal Wedding on April 29, 2011 in London, England. The marriage of Prince William, the second in line to the British throne, to Catherine Middleton is being held in London today. The Archbishop of Canterbury conducted the service which was attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding and street parties are being held throughout the UK. (Photo by Tom Dulat/Getty Images)

“A guide horse is an experimental mobility option for blind people who do not wish to or cannot use a guide dog. They are provided by The Guide Horse Foundation, founded in 1999 to provide miniature horses as assistance animals to blind users living in rural environments”. – Wikipedia

Photo: Shari Bernstiel, of Lansdale, Pennsylvania is helped along the sidewalk by Tonto, her guide horse March 19, 2004 in Lansdale, Pennsylvania. Tonto, a minature horse who went through one year of training, acts as Sheri's seeing eye dog and is one of three working guide horses in the United States. (Photo by William Thomas Cain/Getty Images)

A Geminid meteor streaks diagonally across the sky against a field of star trails behind one of the peaks of the Seven Sisters rock formation in this long exposure early December 14, 2007 in the Valley of Fire State Park in Nevada. The meteor display, known as the Geminid meteor shower because it appears to radiate from near the star Castor in the constellation Gemini, is thought to be the result of debris cast off from an asteroid-like object called 3200 Phaethon. The shower is visible every December. (Photo by Ethan Miller/Getty Images)

Fire rises from an oil tank in the port of Es Sider, in Ras Lanuf, Libya January 4, 2016. Firefighters have extinguished two fires at oil storage tanks at Libya's Ras Lanuf terminal, but blazes continue at five tanks in the nearby port of Es Sider after attacks this week by Islamic State militants, a Petroleum Facilities Guards (PFG) spokesman said on Thursday. (Photo by Reuters/Stringer)

A child, from Municipal school Parana, poses during the project “Fencing School” in Rio de Janeiro, Brazil, March 30, 2016. Children in Rio de Janeiro lift their sights and their swords to new idols, as a round of fencing workshops takes to public schools. The International Fencing Federation, together with the Brazilian and state federations, will reach 40 public schools in March and April. The aim is to whip up a following for the Olympic sport, little known in the soccer-mad nation, as Rio sets the stage for the Summer Games in August. (Photo by Sergio Moraes/Reuters)

A man takes photo of his colleague with a mobile phone on the burning oil tanker at the ship-breaking yard in Gaddani, Pakistan, November 2, 2016. Reports state that at least eighteen workers were killed and more than 100 were wounded in a blast at Gaddani ship breaking yard near Karachi on 01 November. Initial reports suggest the blast occurred when a gas cylinder exploded inside an oil tanker being broken up for scrap. (Photo by Akhtar Soomro/Reuters)

A neighborhood watch volunteer stands guard on her street on February 9, 2017 in Peronia, Guatemala. Residents of Peronia, south of Guatemala City organized block by block to secure their community after ten of their neighbors in January were killed, they say, for refusing to pay extortion money to gangs. Armed with machetes and sticks, residents take turns each night, baring strangers' entry into their neighborhoods. Violence and poverty continue to drive emigration from Central America to the United States, even as the Trump administration moves to tighten border security. (Photo by John Moore/Getty Images)

The annual calendar features stunning shots of lighting, cloud formations and the aurora australis. Hundreds of photographers from every Australian state and territory submitted images to the Bureau of Meteorology for selection in the year’s calendar, with only the best chosen to represent the full spectrum of Australian weather. Here: April. A path through the clouds between Townsville and Richmond, Queensland. (Photo by Captain Victoria Harrison/Australian Bureau of Meteorology)