Astronomy Picture of the Day

Explanation: Normal cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. These mammatus clouds were photographed over Regina, Saskatchewan, Canada during the past summer.

National Geographic Photo Contest 2012

It’s that time again…the 2012 National Geographic Photo Contest is in full swing. The contest has reached his midpoint but there is plenty of time to enter before the November 30, 2012 deadline. Photographers of all skill levels – from professional to amateur – across the globe, submitted more than 20,000 entries from 130 countries in last year’s competition. The photographs are judged on creativity and photographic quality by a panel of experts in the field. There is a first place winner in each of three categories: People, Places and Nature, and a grand prizewinner as well.

See contest photos

Biggest Fountain in the world

King Fahd’s Fountain, also known as the Jeddah Fountain, is the tallest water fountain in the world. Located in the coast of Jeddah, west coast of Kingdom of Saudi Arabia. The fountain jets water 312 metres (1,024 ft) above the Red Sea. It was donated to the city of Jeddah by King Fahd, hence its name. The fountain is visible throughout the entire vicinity of Jeddah. The water it ejects can reach a speed of 375 kilometres (233 mi) per hour and its airborne mass can exceed 18 tons. It was constructed between 1980 and 1983 and began operating in 1985. The fountain uses saltwater taken from the Red Sea instead of freshwater. It uses over 500 spotlights to illuminate the fountain at night.

Oktoberfest 2012

The beer is flowing and carnival rides running again at this year’s 179th Oktoberfest in Munich. Known as the world’s largest beer festival, the event dates to 1810 when Crown Prince Ludwig was married to Princess Therese and the people of Munich were invited to attend the festivities. More than 6 million people are expected to attend this year’s festival, which runs until Oct. 7. — NOTE: We’re going to be asking some viewers of The Big Picture to answer one or two anonymous survey questions before viewing the full post or you can choose to send a tweet or Facebook post instead.

The Killer Whale Submarine

This is the streamlined, two-person watercraft that breaches and submerges just like the Orcinus orca after which it is designed. A pilot protected beneath its watertight 1/2″-thick acrylic canopy pushes and pulls twin control levers to articulate the whale’s pectoral fins for rolls and stealthy dives. With a finger on the right lever’s throttle trigger, steering is provided by dual foot pedals that control the vectored thrust of the craft’s 255-hp supercharged Rotax axial flow engine, enabling realistic behaviors such as porpoising or skyhopping.