“A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy”. – Wikipedia

Photo: A “Double Eagle” gold twenty dollar coin is displayed above a catalogue picture showing the reverse side of the coin at Goldsmith's Hall on March 2, 2012 in London, England. Nearly half a million of these coins were originally minted in the midst of the Great Depression in the US. Only 13 are known today after the rest were melted down before they ever left the US Mint, sacrificed as part of a strategy to stabalise the American economy. In 2002 a Double Eagle sold at auction for $7.6 million. (Photo by Peter Macdiarmid/Getty Images)

“The nuclear football (also known as the atomic football, the president's emergency satchel, the button, the black box, or just the football) is a briefcase, the contents of which are to be used by the President of the United States of America to authorize a nuclear attack while away from fixed command centers, such as the White House Situation Room. It functions as a mobile hub in the strategic defense system of the United States. It is a metallic Zero Halliburton briefcase carried in a black leather “jacket”. The package weighs around 45 pounds (20 kilograms). A small antenna protrudes from the bag near the handle”. – Wikipedia

Photo: A U.S. Military officer carries the “football”, which carries nuclear launch codes, on South Lawn after returning with U.S. President George W. Bush to the White House January 7, 2002 in Washington, DC. (Photo by Mark Wilson/Getty Images)

Storm erupts over Pacific Ocean as plane zooms past at 37,000 ft. The amazing picture shows a massive cloud erupting against a starry night sky as the off-duty airman Santiago Borja flew over the Pacific near Panama City. He had just moments to take the breathtaking snap as the Boeing 767 zoomed by at 37,000 ft on its way from North America to Ecuador. He also had take the picture perfectly in time with the flash of lightning to capture the storm in all its glory. (Photo by Santiago Borja/Solent News)

A U.S. Army crew chief flying on board a CH-47F Chinook helicopter observes the successful test of flares during a training flight in Afghanistan, March 14, 2018. (Photo by Tech. Sgt. Gregory Brook/Reuters/U.S. Air Force)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

Liu Yang, China's first female astronaut, waves during a departure ceremony at Jiuquan Satellite Launch Center, on June 16, 2012. (Photo by Jason Lee/Reuters via The Atlantic)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

Starting on Monday, August 12, Perseid meteors will streak across the summer sky for a couple of nights, offering casual stargazers and serious nighttime photographers a chance to capture a glimpse of the annual meteor shower. Photo: Photographer David Kingham created this composite image from 23 photos on August 12, 2012. (Photo by David Kingham)