Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

The blue-footed booby (Sula nebouxii) is a marine bird in the family Sulidae, which includes ten species of long-winged seabirds. Blue-footed boobies belong to the genus Sula, which comprises six species of boobies. It is easily recognizable by its distinctive bright blue feet, which is a sexually selected trait. Males display their feet in an elaborate mating ritual by lifting their feet up and down while strutting before the female.

Mercury and Maia, fueled and overhauled, are waiting in the Tay at Dundee, for favorable weather to start the flight to the Cape, a distance of 6,370 miles. The composite machine moored in the Tay River, at Dundee, on September 23, 1938. (Photo by AP Photo)

Samba dancers outside Woolwich station celebrate the opening of the Elizabeth Line in London, England on May 23, 2022. Originally due to open in December 2018, the £18.8bn railway links Reading and Essex via central London. (Photo by Jill Mead/The Guardian)

Flight crews of German airliner Lufthansa wear traditional Bavarian folk dress during a photocall to celebrate Oktoberfest at Munich Airport Franz-Joseph-Strauss International on September 15, 2022 in Erding, Germany. Lufthansa cabin crew will dress in the Bavarian traditional costume “Blaudruck Dirndl“ and “Lederhose” on several international flights during the Oktoberfest who kicks off this coming weekend and will run for three weeks. (Photo by Alexander Hassenstein/Getty Images)

A glasses-free Toshiba 55-inch 3-D 4x full HD TV shows the movie, “Coraline” at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 11, 2012 in Las Vegas, Nevada. The TVs are scheduled to be available this year and will come with embedded cameras with facial recognition capability so depending on where you are sitting, the set will adjust the viewing point for the best 3-D experience. (Photo by Ethan Miller/Getty Images)

Italy's Charlene Guignard (L) and Marco Fabbri react to their score after the ice dance rhythm dance competition during the ISU World Figure Skating Championships 2023 in Saitama, on March 24, 2023. (Photo by Kazuhiro Nogi/AFP Photo)