Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

A plane carrying a wing walker crashed at an air show and exploded into flames Saturday, killing the pilot and stunt walker, authorities said. The crash of the 450 HP Stearman happened at around 12:45 p.m. at the Vectren Air Show near Dayton in front of thousands of horrified spectators. No one else was hurt.

Photo: A wing walker performs at the Vectren Air Show just before crashing, Saturday, June 22, 2013, in Dayton, Ohio. The crash killed the pilot and the stunt walker instantly, authorities said. (Photo by Thanh V. Tran/AP Photo)

This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

On Earth Day this year, NASA asked people all around the world a question: “Where are you on Earth Right Now?” To answer this question people were asked to post their selfie on social media. The goal was to use each picture as a pixel in the creation of a “Global Selfie” – a mosaic image that would look like Earth appeared from the space. The 3.2 gigapixel “Global Selfie”, was made the with 36,422 individual images.

Every year, in the Rostov region of Russia, a group of 40 young and not so young rural workers compete in the Bison Track Show, or more affectionately known as: Russian Flying Tractor Racing. In front of crowds numbering up to 30,000 people, a series of smoke spilling, monstrous farming machines tear round an 8km mud track, plowing through lakes and dirt mounds, their turbos screaming and tyres scrabbling to find grip.

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

Hundreds of volunteers stand at Goma International Airport receiving instructions before boarding a plane that will take them to a training center after responding to Democratic Republic of Congo's President Felix Tshisekedi's call to join the army to go to the front lines to fight against the M23 rebellion (March 23 Movement) in Goma, Democratic Republic of Congo, on November 14, 2022. (Photo by Guerchom Ndebo/AFP Photo)

Morocco's Romain Saiss, right, reacts after teammate Abdelhamid Sabiri, not visible, scored a goal on Belgium's goalkeeper Thibaut Courtois, left, during the World Cup group F soccer match between Belgium and Morocco, at the Al Thumama Stadium in Doha, Qatar, Sunday, November 27, 2022. (Photo by Frank Augstein/AP Photo)