Mysterious Fairy Circles of Namibia

In the grasslands of southern Africa, there are thousands of circular barren patches of land called ‘fairy circles’. They grow between 2 meters to 15 meters in diameter, and occur amidst grassy vegetation, specifically in Namibia. But they are also present in Angola and South Africa.

The circles are found in a band about 160 km inland, stretching south from Angola for about 2,400 km. Located in a remote and inhospitable stretch of land that is over a hundred miles from the nearest village. The circles have been studied since they were reported on in 1971, but no conclusive evidence of their cause has been found.

According to a local Himba residents, the circles are caused by a dragon that lives beneath the earth’s crust whose fiery breath bubbles to the surface, burning the vegetation into near-perfect circles. Others have postulated that the phenomenon is caused by ants, termites, radioactive soil or toxins secreted by the Damara euphorbia, a poisonous endemic plant.

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New research may now have yielded a more credible explanation for the fairy circles. A German biology professor Norbert Juergens of the University of Hamburg, has discovered that the intriguing phenomenon is actually the result of sophisticated ecological engineering by the sand termite Psammotermes allocerus.

The sand termite was found in 80-100% of the circles, and in 100% of newly formed circles and was the only insect to live across the range of the phenomenon. The termites create the fairy circle by consuming vegetation, and burrowing in the soil to create the ring. The barren circle allows water to percolate down through sandy soil and accumulate underground, allowing the soil to remain moist even under the driest conditions. Grasses grow on the edges of the circle due to the stored underground water, which the termites will feed upon and slowly increase the size of the circle. Because of this behavior, the sand termites cultivate their own sources of food and water, creating a local ecosystem in a manner similar to the common beaver.

Walter R. Tschinkel, a biologist at Florida State University who also researched the fairy circles, challenged Juergens’s findings saying that Juergens "has made the common scientific error of confusing correlation (even very strong correlation) with causation." Previously, Tschinkel had searched for harvester termites without success.

Juergens responded by saying that Dr. Tschinkel was “looking for the wrong termites”. Sand termites are different from harvester termites and live deep beneath the circle, do not create mounds or nests above ground and move in such a way as to leave no tracks in the sand.

The debate has been ongoing for some time as to the cause of the formation of the circles, and it’s likely to go on in future. The Himba people are, however, unconcerned. To them, there is nothing to explain: the circles are “footprints of the gods.”

Sources: Wikipedia, NyTimes, Independent Online

The Beautiful Fukang Meteorite

The Fukang meteorite, believed to be some 4.5 billion years old, which is as ancient as Earth itself, was unearthed near a town of the same name in China, in 2000. It is a pallasite, a type of meteorite with translucent golden crystals of a mineral called olivine embedded in a silvery honeycomb of nickel-iron. It’s a gorgeous meteorite, and possibly the most stunning extraterrestrial piece of rock man has ever seen.

The Fukang meteorite was found by a hiker. The man had often stopped and had lunch on this giant rock, and he always wondered what the metal and crystals were. He finally took a hammer and chisel and broke some pieces off, which he sent to the USA to confirm that it was a meteorite.

The original meteorite weighted just over a thousand kilogram, but the rock was so brilliant that everybody wanted a piece of it. Since then it has been divided into dozens of thin slices and auctioned or distributed around the world.

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A total of thirty-one kilograms of specimen is on deposit at University of Arizona. Marvin Kilgore of the University of Arizona's Southwest Meteorite Centre holds the largest portion weighing at 420 Kg. In 2008, this piece was expected to fetch $2 million at an auction at Bonham's in New York, but unfortunately, the prospective bidders were more impressed with a couple of pieces of 130-million-year-old fossilized dinosaur’s dung that day, which sold at more than twice the estimate.

According to Bonhams, pallasites are composed of approximately 50 per cent olivine and peridot crystals and 50 cent nickel-iron, and thought to be the relics of forming planets. They apparently make up less than one per cent of meteorites. They are believed to originate from deep inside intact meteors created during the formation of the solar system about 4.5 billion years ago and very few specimens are thought to have survived their descent through Earth's atmosphere.

Photo credit: unknown

Sources: The Daily Mail, The Register, Wikipedia

The Most Spectacular Gemstone : Opal

Opal is one of the most beautiful of gemstones. These stones can flash every color of the spectrum with a brilliance that can even surpass that of diamond. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare, whereas white and greens are the most common. Some rare specimens produce brilliant color flashes when turned in the light.

For instance, a new Opal was discovered in the Welo district of Ethiopia recently, that took the gem world by storm. Found in the Welo Amhara Regional State Highland plateau 2.500 – 3.200 meters above sea level, this new gemstone looks like a miniature underwater scene from the ocean when held against the light. Opals such as the Welo Opal can can command prices per carat that rival the most expensive diamonds, rubies and emeralds.

The Welo Opal

Here is another brilliant Opal – the Fire Opal, also called Mexican fire opals because they are found in the state of Querétaro in Mexico. It looks like someone put a sunset inside the stone.

The Lightning Ridge Black Opal is another stunning example.

See more pictures of Opal here.

Rare Weather Phenomenon Creates River of Clouds Over Grand Canyon

A rare weather phenomenon that affects the area only about once a decade, filled the Grand Canyon in the U.S. with a dense, white fog at the end of November. The phenomenon, known as "temperature inversion," happens when the temperature profile of the atmosphere is inverted from its usual state, and cooler air is trapped at the earth's surface by warmer air above.

Typically, the temperature of air in the atmosphere falls the higher up in altitude you go. This is because most of the suns energy is converted into heat at the ground, which in turn warms the air at the surface. The warm air rises in the atmosphere, where it expands and cools. When temperature inversion occurs, the temperature of air actually increases with height. The warm air above cooler air acts like a lid, trapping the cooler air and fog at the surface and preventing it from rising.

Temperature inversions happen once or twice a year, typically in the winter months. However, these inversions are partial and cover only few parts of the Grand Canyon. The most recent inversion happens only once every 10 years, because the fog filled up the entire canyon and it happened on a cloudless day.

AccuWeather.com Meteorologist Andy Mussoline explained the factors that contributed to the event.

"First, there was higher-than-normal moisture in the canyon," he said. "There was 0.75 of an inch of liquid precipitation that fell between Nov. 20 and Nov. 24 at the Grand Canyon National Park Airport [both snow and rain]. Normal precipitation during that time is only 0.19 of an inch, which converts to nearly 400 percent of normal precipitation within about a week of the event."

“Additionally, the average high temperature for this time of year is about 48 degrees Fahrenheit, which means there would be less evaporation of that precipitation than there would be in the summer months. This allowed more moisture to stay in the air inside the canyon.”

"A high pressure system settled into the region late last week and allowed for clear skies and calm winds, two important weather conditions that allow the air near the ground to cool rapidly," Mussoline said. "The rapid cooling of the ground allowed a temperature inversion to form."