Tundra

Tundra are among Earth's coldest, harshest biomes. Tundras ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy and rainfall is scant. Tundra lands are snow-covered for much of the year, until summer brings a burst of wildflowers.

Mountain goats, sheep, marmots, and birds live in mountain, or alpine, tundra and feed on the low-lying plants and insects. Hardy flora like cushion plants survive on these mountain plains by growing in rock depressions where it is warmer and they are sheltered from the wind.

The Arctic tundra, where the average temperature is 10 to 20 degrees Fahrenheit (-12 to -6 degrees Celsius), supports a variety of animal species, including Arctic foxes, polar bears, gray wolves, caribou, snow geese and musk-oxen. The summer growing season is just 50 to 60 days, when the sun shines 24 hours a day.

The few plants and animals that live in the harsh conditions of the tundra are essentially clinging to life. They are highly vulnerable to environmental stresses like reduced snow cover and warmer temperatures brought on by global warming.

The Arctic tundra is changing dramatically due to global warming. Already, more southern animals like the red fox have moved onto the tundra. The red fox is now competing with the Arctic fox for food and territory, and the long-term impact on the sensitive Arctic fox is unknown.

It is the Arctic's permafrost that is the foundation for much of the region's unique ecosystem, and it is the permafrost that is deteriorating with the warmer global climate. Permafrost is a layer of frozen soil and dead plants that extends some 1,476 feet (450 meters) under the surface. In much of the Arctic it is frozen year round. In the southern regions of the Arctic, the surface layer above the permafrost melts during the summer and this forms bogs and shallow lakes that invite an explosion of animal life. Insects swarm around the bogs, and millions of migrating birds come to feed on them.

With global warming, the fall freeze comes later and more of the permafrost is melting in the southern Arctic. Shrubs and spruce that previously couldn't take root on the permafrost now dot the landscape, potentially altering the habitat of the native animals.

Another major concern is that the melting of the permafrost is contributing to global warming. Estimates suggest that about 14 percent of the Earth’s carbon is tied up in the permafrost. Until recently, the tundra acted as a carbon sink and captured huge amounts of carbon dioxide from the atmosphere as part of photosynthesis. This process helped keep the amount of this greenhouse gas from accumulating in the atmosphere.

Today, however, as the permafrost melts and dead plant material decomposes and releases CO2, the tundra has flipped from a carbon sink to a carbon contributor.

Venice Floods Reach Five Feet, But Life Goes On

December 2, 2008--Ignoring a mayoral request to stay indoors on Monday, Venetians and tourists wade and float through Venice's worst floods in 22 years.

The Italian island city saw waters as deep as 5 feet (155 centimeters)--the fourth deepest since the city began keeping flood records in 1872. The record, however, still stands: A 1966 flood put Venice under 76 sloshing inches (194 centimeters) of the wet stuff. "Venice is completely paralyzed," said a local official of the extreme floods that crested December 1, 2008, according to the Times of London.

Apparently these gondoliers didn't get the message. Shown breakfasting Monday, they exemplify the locals' rubber-booted fortitude in the face of floods, which occur several times a year. Outside the Doge's Palace (right), Venice's Piazza San Marco is hidden by floodwaters nearly as high as cafe tables on December 1, 2008.

The flood put nearly the entire city underwater.

Five years ago, the city began building a $5.5-billion system of offshore dams, expected to be completed in 2011. Such seawalls should prevent floods like this week's. The floods couldn't deter these shoppers, who donned tall boots and perused a pastry shop in Venice on December 1, 2008.

Mayor Massimo Cacciari urged residents to stay indoors and tourists to "think again" about visiting, the Scotsman reported.

"It all happened so quickly--within 20 minutes we were up to our waists in water," a shopkeeper told the newspaper

A woman waits for a boat amid floodwaters in Venice, Italy, on December 1, 2008.

Monday's extreme water levels led officials to suspend ferry and water taxi services in the city.

"We sent out another warning about very high tides this morning," said Leonardo Cossutta, who runs the Venice Tide Center's control room, on December 2, the New York Times reported.

He said transportation was returning to normal, although some canal ferries were forced to use alternative routes. Heightened canal water levels had made it impossible for the boats to fit under some bridges.
A woman crosses Venice's Piazza San Marco on an elevated walkway on December 2, 2008. The water had risen up to five feet (1.5 meters) high on Monday before beginning to recede on Tuesday.

The temporary walkway is designed to help visitors and residents navigate the city during flooding. Workers were unable to install most of the city's platforms, however, as the water rose too quickly

Alabama

The tranquil pace of life in Monroe County, Alabama, has nurtured some notable literary figures. Harper Lee and Truman Capote have called the county home.

Alabama Information and HistoryHome to five Native American tribes (Creek, Cherokee, Chickasaw, Choctaw, and Seminole), this area of fertile soils was the heart of the "cotton kingdom" before the Civil War.

Today Alabama lies at the center of a revitalized Deep South. Birmingham, the state's largest city, has become a focus for medical research, and is a major manufacturer of steel, iron, and coal. Leading industries include textiles and apparel, rubber and plastics, paper, chemicals, primary metals, and automobile manufacturing. The Alabama Research and Education Network, first state-funded computer network in the U.S., links universities and school systems across the state.

The Tennessee-Tombigbee Waterway, a transportation corridor for industry and agriculture, connects 16,000 miles of U.S. inland waterways to the Gulf of Mexico via Mobile's port.

ECONOMY

Industry: retail and wholesale trade, services, government, finance, insurance, real estate, transportation, construction, electrical equipment.
Agriculture: poultry, forest products, cattle, nursery stock, cotton, eggs, peanuts, soybeans.

Sources of Saturn Moon's Supersonic Water Jets Revealed

Richard A. Lovett

Jets of water vapor blasting out of Saturn's moon Enceladus at supersonic speeds are coming from vents each about the size of a professional sports stadium, a new study says.

Scientists first saw a plume of water vapor and dust shooting from the moon's south pole in 2005.
Research later determined that the water geysers are gushing out at about 1,000 miles (1,609 kilometers) an hour from a series of 100-mile-long (161-kilometer-long) fissures dubbed tiger stripes.

The new finding indicates that the gas and dust are escaping from relatively small vents along those fissures.

"We are making the distinction between the whole plume and individual jets in it, like streamers or searchlight beams," said team member Larry Esposito, of the University of Colorado in Boulder.

The researchers think the jets are formed when liquid water from pools not far beneath the icy moon's surface accelerates as vapor passes through a maze of nozzle-like channels before erupting into space.

"It's one more little piece of evidence that the source of the plume is liquid water," said lead study author Candice Hansen, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Swimming Pools and Ping Pong

The Cassini spacecraft observed the way the plume dimmed starlight shining from behind as the probe zipped past Enceladus in 2005 and 2007.

The data allowed scientists to determine the vapor jets' speed and density as low as 9 miles (15 kilometers) above the surface.

That, in turn, allowed them to calculate the likely size of the vents from which the vapor is emerging.

"It's certain the jets are not coming from the whole fissure," Esposito said.
Instead they are shooting out from regions that are no larger than 0.2 square miles (0.6 square kilometers), although the vents may be even smaller, depending on the temperature of the water vapor, the researchers note.

Overall, about 440 pounds (200 kilograms) of water are being blasted into space every second—roughly the equivalent of a residential swimming pool every few minutes.

But the amount observed in 2007 was less than that seen in 2005.

That was a surprise, the University of Colorado's Esposito said, because in 2007, Enceladus was at a point in its orbit where scientists had calculated that tidal forces from Saturn would stretch the vents wider, increasing their flow.

Instead, the opposite appears to have happened, the scientists report in this week's issue of the journal Nature.

"Sometimes you learn more by being wrong than by being right," study leader Hansen said.

She added that theoretical physicists are already looking at ways to refine their models of the moon to account for the new finding.

"It is the natural back-and-forth ping-pong [of science]," she said.

"You make observations. People have hypotheses and theories about what's going on. [We] take more observations and figure out where we're on the right track and where we probably are not."

The finding does, however, bolster the case for subterranean liquid water, strengthening the argument that Enceladus might be one of the better places in the solar system to look for extraterrestrial life.

In a March 2008 flyby, Cassini dipped into the plume and detected not only water vapor but also methane, carbon dioxide, and other organic molecules.

"We cannot say whether there is life or not," Hansen said. "But if we can conclude that there is liquid water, then we can say at least the ingredients are there.

Oldest Turtle Found; May Crack Shell-Evolution Mystery

Brian Handwerk

Fossils of the oldest-known turtles, unearthed in southwestern China, may help answer an evolutionary enigma—how did the turtle get its shell?

The 220-million-year-old animals did not have full shells, or carapaces, on their backs, researchers found.

But the newfound creatures did sport fully developed plastrons—the flat part of a turtle shell that covers and protects the belly.

The discovery supports the theory that turtle shells formed from the underside—plastron first—and grew bony extensions of ribs and bone formation above backbones that eventually joined to form the classic shell that exists today.

Alternate Theory

An alternate theory of shell evolution suggests that turtle shells developed from the fusion of bony armor plates in the skin, known as osteoderms, seen in some dinosaurs and some modern-day reptiles, including crocodiles.

But the prehistoric turtle, dubbed Odontochelys semitestacea and described in a recent edition of the journal Nature, has no osteoderms.

"So far there is no direct evidence for the osteoderm theory," said study co-author Chun Li of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing.

"On the contrary, here, in our hands, there is an ideal missing link for turtle evolution. It has no osteoderms on its back, but only ossified neural [central] plates and expanded ribs."

The study also notes that embryonic evidence from modern turtles suggests that their shells begin to form in a similar manner.

If plastrons developed first, they may point to a marine lifestyle in which turtle bellies needed protection from predators," Li noted.

"We are not sure if the water [was] marine or [from other water bodies], so we presumed … that the animal inhabited marginal areas of the sea or deltas," he said.

Exciting Discovery

Scientists have waited a long time for a find like Odontochelys, Li said: The previously oldest known turtles featured fully formed shells.

"The new specimens are a very exciting discovery," agreed Robert Reisz of the University of Toronto, who was not involved in the research.

But Reisz suggests an alternate evolutionary interpretation for the intriguing fossils.

"Their argument is valid," he said of Li and colleagues.

"But we argue that it's equally possible that this could already be a [shell] reduction in an earlier turtle that we haven't found. Lots of marine turtles actually reduce their shell once they get into the water."

"Hopefully we'll find more," Reisz added. "We're closing the gap, but there is still a big morphological gap between this turtle and its non-turtle ancestors."

Odontochelys also boasts another feature seen in no other turtles so far—teeth, Reisz added.

"Basically if you look at all the turtles we know, other than this one, they all have a beak rather than teeth," he said.

"Turtles come from reptile ancestors with teeth so we expected this, but it's still a great thing to find."

Tiny Tropical Island Yields a Wealth of Species

Scientists sampled some 4,000 different mollusk species in Espiritu Santo. Mollusk expert Philippe Bouchet speculates that as many as 1,000 of these could be new species.

Among the finds: this sundial snail, already known to science and so named for the swirling pattern on its shell.

In a career spanning dozens of deep-sea expeditions in three oceans, Bouchet has already described more than 400 new mollusk species.



The thick, solid spines of a pencil sea urchin jut out like the writing instruments that lend this creature its name.

These nocturnal animals hide in coral reef cavities during the day and crawl out after dark to forage for food.

Found in the Pacific and Indian oceans, pencil urchins are popular in the aquarium trade because they fare well in captivity. Their sturdy spines are sometimes used for making mounts for jewelry.


A ballerina-like red dragonfly hunts for smaller insects on a sunlit rock by the side of a small river in Espiritu Santo, Vanuatu, in the South Pacific.

Insect expert Emmanuel Boitier spotted this one catching tiny flies before it darted off to the next rock. This genus of dragonfly is found in Asia, Africa, and Australia as well as the southwest Pacific.

Discoveries like these will provide a benchmark for measuring future ecological change in a little-studied corner of the world



French insect expert Emmanuel Boitier came across this cicada at night, newly hatched and coming to life under a leaf. The insect was found in a forest on Espiritu Santo, the 1,548-square-mile (4,010-square-kilometer) island in Vanuatu where the Santo 2006 expedition took place.

After a few hours, as the young insects dry off, their salmon color usually changes to brown or green.



Slipper lobsters usually resemble stones, blending in with their rocky habitats.

This one, collected by crustacean experts during the Santo 2006 expedition, funded in part by the National Geographic Society's Committee for Research and Exploration, bears a bright blue band at its middle--a striking contrast with the dull color of the rest of its body. (National Geographic owns National Geographic News.)

This lobster species is one of many collected during the expedition that are already known to science.


Even on tiny remote islands, scientists can find an impressive array of life.

During the Santo 2006 biodiversity survey in Vanuatu, 153 scientists from 20 countries fanned out across the remote South Pacific island of Espiritu Santo, examining mountains, forests, caves, reefs, and water for all living organisms.

In five months, they collected 10,000 species. Some 2,000 of these may be new to science.

This squat lobster, found in waters 150 meters (492 feet) deep, is one of the new species. Eighty percent of the world's species remain to be discovered, notes French scientist Philippe Bouchet, one of the expedition's leaders.

Ancient Armenian Origins

One of the world's oldest civilizations, Armenia once included Mount Ararat, which biblical tradition identifies as the mountain that Noah's ark rested on after the flood.

It was the first country in the world to officially embrace Christianity as its religion (c. 300). In the 6th century b.c.e., Armenians settled in the kingdom of Urarty (the Assyrian name for Ararat), which was in decline. Under Tigrane the Great (fl. 95-55 c.c.e.) the Armenian empire reached its height and became one of the most powerful in Asia, stretching from the Caspian to the Mediterranean Seas. Throughout most of its long history, however, Armenia has been invaded by a succession of empires. Under constant threat of domination by foreign forces, Armenians became both cosmopolitan as well as fierce protectors of their culture and tradition. Over the centuries Armenia was conquered by Greeks, Roman and, Persians.

The Temple of Garni, built by the Romans during their occupation of Armenia

Armenians consider themselves direct descendants of Noah, survivor of the Biblical flood. According to Genesis, ...the boat came to rest on a mountain in the Ararat range. Ararat, located in the heart of Armenia, was a Holy Mountain for the peoples of the ancient world. Many ancient scriptures placed the Biblical Garden of Eden in the Land of Armenia also called the Land of Ararat. Tradition states that Noah founded Nakhichevan, the oldest of the Armenian cities. Moses Khorenatsi , historian of the 5th century, presents a detailed genealogy of the Armenian forefather Haik from Japheth, Noah's son. Thus, the territory of the Armenian Plateau is regarded as the cradle of civilization, the initial point for the further spreading of mankind all around the world.
Depiction of Armenian warrior from Persopolis.

The oldest myths reflect the wars of ancient Armenians against the neighboring Assyrians. Haik, considered the patriarch of the Armenian people, led his army to defeat the Assyrian giant Baeleus. By approximately 2100 BC, a prototype of the first Armenian state was founded. Even now, Armenians call themselves Hai (pronounced high), and their country - Haik or Haiastan, in honor of Haik. The Hittite scripts also mention a Haiasa country. Meanwhile, the Assyrian cuneiform writings designate Armenia as Urartu (Arartu), which means Ararat.

The Old Testament also associates Armenia with the Mount Ararat (the Kingdom of Ararat). In ancient times, Armenia was equally associated with the rivers Tigris, Euphrates, Araks and Kura. That is why the neighboring Assyrians also called Armenia, Nairi, standing for Riverland, Country of Rivers. Haik, once thought to be just a hero of an epic legend, is presently accepted by some researches as an actual chieftain of Armens in the 3rd millennium BC. Historians proved that later Haik was deified and proclaimed the prime god in the pantheon of gods in the pagan Armenia. One of Haik's most famous scions, Aram, considerably extended the borders of his country, transforming it into a powerful state. Since then, Greeks and Persian began to call the country Armenia, i.e. the country of Aram.

Aram's son, Ara the Beautiful succeeded him. A very romantic Armenian legend tells that Ara was so handsome that the Assyrian Queen Semiramis (the same who founded Babylon and planted its marvelous hanging gardens) fell in love with him. Ara repeatedly rejected her love proposals until the desperate queen began war with him. The Assyrians troops won the furious battle, and Ara was killed, in despite of Semiramis's order to preserve his life. Inconsolable Semiramis reputed to be sorceress took his body and tried in vain to enliven him. When Armenians advanced to avenge their leader, she disguised one of her lovers and spread the rumor that Gods brought Ara back to life. As a result, the war was ceased.

Rise of an Armenian Kingdom
Armenian vassal bringing tribute to Persian King from great staircase at Persopolis.

Aram's son, Ara the Beautiful succeeded him. A very romantic Armenian legend tells that Ara was so handsome that the Assyrian Queen Semiramis (the same who founded Babylon and planted its marvelous hanging gardens) fell in love with him. Ara repeatedly rejected her love proposals until the desperate queen began war with him. The Assyrians troops won the furious battle, and Ara was killed, in despite of Semiramis's order to preserve his life. Inconsolable Semiramis reputed to be sorceress took his body and tried in vain to enliven him. When Armenians advanced to avenge their leader, she disguised one of her lovers and spread the rumor that Gods brought Ara back to life. As a result, the war was ceased.

In 612 BC the Medes destroyed Nineveh and brought the Assyrian power to an end. Armenia's eternal antagonist abandoned the political arena. Some 50 years later, the king Tigranes the First in alliance with Cyrus the Great, founder of Achaemenid dynasty conquered the lands controlled by the Medes and reinforced the Armenian kingdom. Tigranes the First had 3 sons; the third son's name was Vahagn the Dragonfighter. The Armenian pagan tradition covered this Vahagn with glory and legends: he was even deified and worshipped like Hercules. However, the era of peace ended as a number of weak and insignificant kings ruled Armenia over the following years, and finally the country became tributary to Persia. An inscription on a rock (around 520 BC) called the Behestun Stone, found in Iran, mentions Armenia in the list of countries Darius I controlled. The dynasty of Hayk stopped: the kings of Armenia were henceforward anointed by the Persian kings. During the following centuries the Armenian troops fought for Persia in all major battles. The Armenian cavalry was well known for its valor. Vahe, the last offspring of Hayk dynasty, was killed in 331 BC, fighting for Darius in a battle against Alexander the Great.

Armenia regained independence after the death of Alexander the Macedonian, when the monarchy of the latter was split into many parts. By 190 BC, Prince Artashes, the governor of Greater Armenia, united the shattered Armenian lands, establishing the Atashesian dynasty. He built the city of Artashat. According to some Roman historians, the construction of this new Armenian capital was supervised by famous commander Hannibal the Carthaginian, who took refuge in Armenia fleeing from the Romans. The country enjoyed peace and prosperity under the rule of Vagharshak, who came to throne in 149 BC. He set up the institute of nobility in his kingdom and established the new senior official ranking system. Vagharshak made the city of Armavir his royal residence. Several Greek inscriptions from around that period found in Armavir witness about the influence of the Greek culture in Armenia.

Aram's son, Ara the Beautiful succeeded him. A very romantic Armenian legend tells that Ara was so handsome that the Assyrian Queen Semiramis (the same who founded Babylon and planted its marvelous hanging gardens) fell in love with him. Ara repeatedly rejected her love proposals until the desperate queen began war with him. The Assyrians troops won the furious battle, and Ara was killed, in despite of Semiramis's order to preserve his life. Inconsolable Semiramis reputed to be sorceress took his body and tried in vain to enliven him. When Armenians advanced to avenge their leader, she disguised one of her lovers and spread the rumor that Gods brought Ara back to life. As a result, the war was ceased.

Tigranes the Great of Armenia
Vagharshak's son Arshak and his grandson Artashes were very successful rulers as well, but it was perhaps the son of the latter, Tigranes II, who distinguished himself as the most glorious among all Armenian kings.
He succeeded his father in 95 BC. Brother-in-law and true ally of Mithridates the Great, the glorious King of Pontus, he struggled together with his formidable relative against the Roman dominance. Tigranes the Second also known as Tigranes the Great, extended the Armenian borders from Caspian Sea to Egypt, gaining full control over the vast territories. After having subdued the provinces in Syria, Cappadocia and Mesopotamia, Tigranes also conquered Palestine, taking many thousands of prisoners. He united all the Armenian lands and built 4 large cities in different parts of his empire all 4 called Tigranakert. Just like his father Artashes, Tigranes transported from Greece many statues of the Greek Gods. A gigantic statue of Zeus was erected in Ani fortress, and sanctuary for Anahit (Aphrodite) was raised in the city of Ashtishat.

Herod's Lost Tomb

Herod's bloody reputation has always hidden another side of one of the Bible's greatest villains - an architectural mastermind of breathtaking proportions. An Israeli archaeologist claims to have found Herod's most intimate creation of all - his tomb.

Herod's tepidarium (Roman sauna bath) is a building with the oldest dome in Israel, where Herod entertained friends.Herod built single-mission barges made of a mixture of Italian concrete and stones that were poured into wooden frameworks.
Herodium served as a pleasure palace and Herod's chosen tomb.

Massive Prehistoric Fort Emerges From Welsh Woods

James Owen
Cloaked by time's leafy shroud, the prehistoric settlement of Gaer Fawr lies all but invisible beneath a forest in the lush Welsh countryside.

Commanded by warrior chiefs who loomed over the everyday lives of their people, the massive Iron Age fortress once dominated the landscape. Now the 2,900-year-old structure lives again, thanks to a digital recreation following a painstaking survey by the Royal Commission on the Ancient and Historical Monuments of Wales.

The Iron Age hill fort in central Wales was a major feat of civil engineering, researchers say.

"Because Gaer Fawr is densely wooded, it's been little understood in the past," said Royal Commission archaeologist Toby Driver.

"Our new survey has shown what a very impressive and advanced building it was.

"This was a very bold architectural statement by Iron Age people," he said.

Survey Says

The study involved thousands of measurements taken in 2007, which were used build a digital terrain model of the 21-acre (5.8-hectare) site.

Measurements were made manually using lasers beamed to handheld posts, each bearing a reflector, Driver said.

"The thought behind the survey was that if we could map the contours underneath the woods, we could then strip the trees off and then see what the fort looked like in the landscape," he added.

The results show the oval-shaped stronghold was defended by five tiers of stone-faced earthen ramparts, each measuring up to 26 feet (8 meters) in height.

Two entranceways led up to gates to the northeast and southwest of the summit, where a timber fortress once stood.

The hill fort's flat summit was later extended to the west, possibly to accommodate a growing population.
"It's not a single build," Driver said. "New ramparts and new gateways were constructed over earlier ones."

Monumental Task Past archaeological finds, including a nearby cache of Bronze Age weapons, suggest the hill fort was active from about 900 B.C. until the Roman invasion of Britain in A.D. 43.

A bronze sculpture of a wild boar—a symbol of power—discovered in the 19th century in an adjacent field might be a relic of the ancient chiefs who ruled over Gaer Fawr, Driver suggested.

"It's a very rare find," he said. "One could conceive someone fairly powerful running the fort with this bronze boar mounted on his helmet."

The study team says the fort occupied a strategically important area for trade and agriculture between the fertile plains of England and the Welsh hills.

The border region has the highest concentration of Iron Age hill forts in Western Europe, Driver noted.

"This land would have supported a lot of people and hill forts would have risen up to control these populations," he said.

Phil Bennett is archaeological manager of one of the few extensively excavated Iron Age forts in Britain: Castell Henllys in southwestern Wales.

Larger hill forts such as Gaer Fawr commanded the surrounding landscape not just visually, but in terms of natural resources, Bennett said.

Huge amounts of timber would have been required both for building the fort palisades—strong defensive fences—and the dwellings people lived in, he said.

Roundhouses—circular buildings used as living quarters—excavated at Castell Henllys, for example, are estimated to have required some 30 oak trees, 80 to 100 hazel bushes, and 2,000 bundles of reeds, Bennett said.

(Related: "Badgers, Rabbits Undermine England's Ancient Monuments" [July 11, 2008].)

Status Symbol

"We think these hill forts owed as much to elites showing off their status and power as any real need for defense," he added.

The terraced ramparts wouldn't have held an enemy at bay for long, according Bennett.

"Probably what was going on in the Iron Age was raiding rather than sieges and open warfare," Bennett said. "They would have taken things like cattle and people as slaves."

Another newly revealed feature at Gaer Fawr also hints at a much later period of occupation.

An angular bank dividing the interior of the fort is so different from the site's other earthworks that researchers suspect it dates to early medieval times.

"The fort has these prehistoric curving ramparts, but when you get to the top there's this big, straight bank which is very unprehistoric," the study team's Driver said.

After the Roman period, Welsh princes rose to prominence in the region, he added. "It may be that Gaer Fawr, in common with other hilltops in central Wales, was occupied by the court or castle of one of these early Welsh princes," Driver said.

Today, the once majestic site is a woodland recreation area.

"It's very difficult to imagine you're walking over an Iron Age hill fort," Driver said.

Dark Matter Proof Found Over Antarctica?

Dark Matter Proof Found Over Antarctica?
Anne Minard

High-energy electrons captured over Antarctica could reveal the presence of a nearby but mysterious astrophysical object that's bombarding Earth with cosmic rays, researchers say.

Or the electrons may be the long-awaited physical evidence of elusive dark matter.

Either way, the unusual particles are exciting for astrophysicists, who say they could someday confirm or deny decades of unproven theories.

"In the first case, we have now seen for the first time a nearby source of cosmic rays. Nobody's seen that before," said study co-author John Wefel, a physicist at Louisiana State University in Baton Rouge.

"In the second case, we may be seeing something even more stupendous."

Annihilation Signal

Cosmic rays are not beams per se but are any protons, electrons, and other subatomic particles that careen toward Earth from a variety of sources, including the supernova explosions that mark the deaths of stars.

Most of the cosmic electrons that reach Earth are low-energy, because the highest-energy ones fizzle the fastest and don't last long enough to get here.

Capturing any electrons at all from the high end of the energy spectrum requires a sustained sampling effort.

The authors of the new study flew a balloon-borne particle collector called the Advanced Thin Ionization Calorimeter (ATIC) over Antarctica.

Circular winds at that latitude allow the balloon to stay aloft for up to 30 days at a time, capturing electrons and measuring their charges, energies, and trajectories.

The team got a surprise: ATIC found inflated numbers of high-energy electrons that match the signal expected from the destruction of dark matter.

Dark matter is one of astrophysics' greatest enigmas. It is thought to be five times more common than visible matter, but there is no proof of what it is made of.

The existence of dark matter has largely been inferred from its gravitational effects, such as the fact that most galaxies have enough mass to remain as well-defined objects despite having too little visible matter to account for the necessary gravity.

A few exotic particles have been suggested as dark matter ingredients. One of these, named the Kaluza-Klein particle, is predicted to have the same mass as 550 to 650 protons.

When these theoretical Kaluza-Klein particles collide and annihilate, they're expected to produce electrons with energies between 550 and 650 gigaelectron volts, or GeV. One GeV is roughly the energy locked up in the mass of a single proton, according to Einstein's famous formula E=mc2.

At 620 GeV, the odd energy spike in the Antarctic electrons falls within that range, the authors report in this week's issue of the journal Nature.

Mystery Object

As an alternative theory, the authors say, a nearby astrophysical object could be churning out high-energy electrons that are reaching Earth.

Possibilities include a pulsar, which is the highly magnetic, rotating remnant of a collapsed star, or a microquasar, the luminous, energetic collection of material orbiting a small black hole.

Astrophysicist Okkie de Jager, of North-West University in Potchefstroom, South Africa, and colleagues announced the discovery in April that two pulsars—Geminga and B0656+14—are local sources of high-energy cosmic rays.

These pulsars could be producing the newly discovered electrons, de Jager said.

"I would put my money on a local source, simply because we do have the smoking gun to this effect," said de Jager, who was not involved in the new study.

Yousaf Butt, an astrophysicist at the National Academy of Sciences, wrote a commentary on the work also appearing in Nature.

"Let's not forget that a completely new type of astrophysical object could also produce the detected electron excess," Butt said.

"After all, pulsars were discovered only in 1967, and until 1992 we were blissfully unaware of microquasars."

For its high-energy electrons to reach Earth, such an object would need to be close, astrophysically speaking—within about 3,000 light-years of Earth.

Undecided

Study co-author Wefel said his research team doesn't favor either theory just yet.

"We're sort of stuck in between the two. We can't decide."

No known object precisely matches the data on hand, and the results aren't conclusive for the detection of dark matter, he noted.

"We just do not have enough events to prove they're responsible," he said, referring to the Kaluza-Klein particles. "It's suggestive but it's not proven."

Further sampling is key, he said, but funding has not been renewed for his team to continue using ATIC over Antarctica.

Giant neutrino telescopes like IceCube, A University of Wisconsin-led project built at the South Pole, could find more dark matter clues.

And an instrument called CALorimetric Electron Telescope, or CALET, is now being designed in Japan with the hope that it will join the International Space Station in 2013.

CALET would collect electrons over Earth for at least 1,000 days, as opposed to ATIC's 30.

Fermi, NASA's gamma-ray space telescope formerly known as GLAST, is also capable of measuring an electron spectrum. And the European Union's Cherenkov Telescope Array, now under development, may be able to locate dark matter hot spots in the universe.

Finally, when it's running smoothly, the Large Hadron Collider in Europe will function in part as an experimental dark matter factory, producing collisions at 14,000 GeV that could help shed light on dark matter's exotic particles.

Cancer victim Randy Pausch's wife speaks

http://news.yahoo.com/video/health-15749655/randy-pausch-s-last-lecture-wife-s-take-29308901.html

New Finds at King Herod's Tomb

Archaeologists exploring King Herod's tomb complex near Jerusalem have uncovered rare Roman paintings as well as two sarcophagi, or stone coffins, that could have contained the remains of Herod's sons.

In May 2007, veteran Hebrew University archaeologist Ehud Netzer solved one of Israel's great archaeological mysteries when he first uncovered the remains of Herod's first century-B.C. grave at the Herodium complex, located 9 miles (15 kilometers) south of Jerusalem.

King Herod, appointed by the Romans to rule Judea between 37 and 4 B.C., is renowned for his monumental construction projects, including the Jewish Temple in Jerusalem, the Caesarea complex, and the palace atop Masada.

Herod constructed Herodium as a massive and lavish administrative, residential, and burial center. The style of the paintings has not been seen before in the Middle East, according to Netzer, who has been working amid Herod's ruins since the 1960s, at times with funding from the National Geographic Society's Committee for Research and Exploration.
The window painting style existed in Rome and Campania only between 15 and 10 B.C. Netzer's team believes Italian artists were brought to the Holy Land to decorate this theater, as happened at a site in nearby Jericho.

"Normally in Judean art you wouldn't paint scenes such as these with animals. The style is so similar to what is known from Italy, it really looks like a team came over to do the painting," said Rachel Chachy-Laureys, a surveyor working with Nezter. "It fits the context."
In addition, two relatively intact coffins, perhaps belonging to Herod's sons, were recently found in the mausoleum and show no signs of deliberate damage. Herod was rumored to have murdered his sons.

The coffins are in good shape compared to what archaeologists are labeling Herod's sarcophagus, discovered in 2007 and crafted of reddish-pink limestone with carved rosettes.

Herod's coffin was likely vandalized during the first Jewish revolt against Roman rule sometime between A.D. 66 and 72, Netzer said.

The king was likely despised by Jewish rebels as a puppet appointed by Judea's Roman rulers, and Netzer said the damage was probably a deliberate expression of hatred or revenge.

The Mystery Remains

One big question remains: Where is Herod's body?

"We have only found a very small number of human bones at the site and have not been able to come to any conclusions," Netzer said. "We have not yet finished digging and have only uncovered a small area."

But he does not believe the king's remains will ever be recovered.

At the conclusion of the first Jewish revolt in A.D. 70, the rebels handed the site back over to the Romans.

Jewish fighters also briefly made use of the site during the Bar Kokhva revolt 50 years later, building a network of tunnels that served their efforts at guerilla warfare against the Romans.

Netzer began to excavate at the Herodium site in 1972. He and his colleagues Ya'akov Kalman, Ro'i Porath, and Chachy-Laureys—with the assistance of local Bedouins—began excavations higher up on the mountain's slope in 2006.

The Israel Museum is slated to open an exhibition in 2010 of archaeological findings from Herodium, which is managed by Israel's Nature and National Parks Protection Authority.

Netzer revealed new discoveries at a Wednesday press conference in Jerusalem.

Recent excavations uncovered an elaborate theater dating slightly earlier than Herod's burial complex that had been demolished to enable construction of the artificial mountain that served as his tomb.

The walls of the theater's loggia—a balcony that served as a VIP room and viewing box—are decorated with well-preserved Roman paintings of windows and outdoor scenes.

Mysterious Aurora Spotted on Saturn

November 13, 2008—Saturn has given scientists a light show like nothing they've ever seen, NASA announced Wednesday.

The Cassini orbiter has captured a unique aurora (shown in blue) on the ringed planet that illuminates much of its northern polar cap.

Auroras occur when charged particles stream across a planet's magnetic field lines and into its atmosphere.

But they don't usually light up such a wide area.

"It's not just a ring of auroras like those we've seen at Jupiter or Earth," Tom Stallard, a scientist at the University of Leichester, U.K., said in a statement. He added that "finding such a bright aurora here is a fantastic surprise."

The newfound aurora is often elusive, sometimes disappearing within 45 minutes, the researchers say.

Explaining the oddity will undoubtedly unearth new laws of physics found only on Saturn, said Nick Achilleos of University College London.

Chinese Kingdoms Rose, Fell With Monsoons?

Ker Than

Throughout centuries, the fortunes of China's ancient kingdoms rose and fell with monsoon cycles, a new study suggests.

The discovery is based on a nearly 2,000-year-old record of monsoon activity recently discovered in a cave.
Monsoon winds carry rain-laden clouds through China every summer, providing nearly 80 percent of the annual precipitation in some parts of the country.

When the winds are weak, little to no rain reaches large expanses of China, often plunging those areas into drought.

The new study "is a brilliant analysis of the problematic coincidence of abrupt climate changes and changes in political organization," said Harvey Weiss, an archaeologist at Yale University who was not involved in the study.

"Really Surprised"

In the Wanxiang cave in north-central China, researchers discovered a record of monsoon activity preserved in a stalagmite—a rock formed by mineral-rich waters dripping onto the cave floor year after year.

The rock had been growing continuously for 1,800 years, from A.D. 190 to 2003.

Like trees, stalagmites have annual growth rings that can provide clues about local environmental conditions for a particular year.

The team measured the amount of oxygen-18—a rare form of "heavy" oxygen—in the stalagmite growth rings. Growth rings with large amounts of oxygen-18 indicate years of weak summer monsoons and less rains.

Comparing the stalagmite record with Chinese history, the researchers found that a period of strong monsoons was associated with the "golden age" of the Northern Song dynasty.

During that time, improved rice yields allowed the population to increase from 60 million to as many as 120 million.

"I was really surprised," said study co-author Hai Cheng, a geologist at the University of Minnesota.

Furthermore, weak monsoon seasons coincided with droughts and the declines of the Tang, Yuan, and Ming dynasties.

Weak monsoons may have helped trigger one of the most tumultuous eras in Chinese history, called the Five Dynasties and Ten Kingdoms period, according to the study, detailed tomorrow in the journal Science.

During this time, five dynasties rose and fell within only a few decades, and China fractured into several independent nation-states.

(Read about the brilliant, cruel emperors of the Han Dynasty in National Geographic magazine.)

"Compelling"

Peter deMenocal is a paleoclimatologist at Columbia University's Lamont-Doherty Earth Observatory in New York.

"The synchrony between these cultural events and climate change events is really compelling," deMenocal said.

DeMenocal's research has examined the role of climate change in the declines of ancient civilizations, including those of the Maya and Mesopotamians.

Throughout history, climate change has likely exacerbated already tense situations within empires caused by political upheavals or societal unrest, he said.

"Climate in many cases acts like the straw that broke the camel's back," deMenocal said.

Continuous Effect

The monsoon effect on China continues today, the study authors added.

Scientists have linked droughts plaguing large swaths of modern China to weakening monsoon winds during the past half century.

"The local government has sometimes had to move people out of some regions because they don't have enough water," said study co-author Cheng.

Monsoon variability in the past was driven by natural influences—such as changes in solar cycles and global temperatures. But today's waning monsoons are the results of human-driven greenhouse gas emissions, the new study suggests.

"I do think it's useful to look at this [study] as a lesson for our future," Columbia's deMenocal said.

"In their time, these ancient cultures were in many ways just as impressive as modern societies."

New Pyramid Found in Egypt: 4,300-Year-Old Queen's Tomb

Tomb Andrew Bossone in Cairo

A new pyramid has been discovered deep beneath Egyptian sands, archaeologists announced today.

The 4,300-year-old monument is believed to be the tomb of Queen Sesheshet, the mother of Pharaoh Teti, the founder ancient Egypt's 6th dynasty.

Once nearly five stories tall, the pyramid—or at least what remains of it—lay beneath 23 feet (7 meters) of sand.

The discovery is the third known subsidiary, or satellite, pyramid to the tomb of Teti. It's also the second pyramid found this year in Saqqara, an ancient royal burial complex near current-day Cairo.

"I always say you never know what the sands of Egypt might hide," said Zahi Hawass, secretary general of Egypt's Supreme Council of Antiquities (SCA).

"This might be the most complete subsidiary pyramid ever found at Saqqara," added Hawass, who is also a National Geographic Society explorer-in-residence. (The National Geographic Society owns National Geographic News.)

Surprise in the Sand

Archaeologists also found remnants of a white limestone casing for the surviving, 16-foot-tall (5-meter-tall) pyramid base. The angle of the base helped them determine that the pyramid's walls stood at a 51-degree angle.

Based on that angle, the team determined that the pyramid was originally 46 feet (14 meters) tall and about 72 feet (22 meters) square at its base.

The researchers were somewhat surprised to find a pyramid at the Teti site, since they thought the area had been thoroughly searched. Archaeologists had already found subsidiary pyramids for Teti's two principal wives Iput I and Khuit, about a hundred years ago and in 1994, respectively.
Teams have been digging in the area for more than 20 years.

"One hundred years ago they used to take sand and put it in unexcavated areas," Hawass said.

"The archaeologists in the past used this area as a location for the sand. No one could think there is anything here."

Tomb robbers, however, had known the pyramid was there—archaeologists found that a shaft had been created to allow access to Sesheshet's funerary chamber.

Due to those assumed tomb raids, archaeologists don't expect to find Sesheshet's mummy when they reach the burial chamber weeks from now. But they do anticipate finding inscriptions about the queen, whose name, perhaps coincidentally, evokes the goddess of history and writing, Seshat.

Mother Love

Starting from the 4th dynasty (2616 to 2494 B.C.), pharaohs often built pyramids for their wives and mothers.

"Mothers were revered in ancient Egypt," said Salima Ikram, a professor of Egyptology at the American University in Cairo, who was not involved in the discovery.

"Building pyramids for one's mother in her dead state … was fairly emphasized in the whole vision of kingship that the ancient Egyptians had," Ikram said.

"That was something that was instituted during [a pharaoh's] lifetime and was a very public way of expressing his debt to her, his connection to her, and her importance in Egypt politically and as a symbol for kingship."

Sesheshet's son Teti might have been more motivated than the average pharaoh to pay homage to his mother. Sesheshet had come from a powerful family and probably supported his ascendancy to the throne during turmoil at the end of the 5th dynasty.

"She's one of the important ladies at that time," said Hakim Haddad, general director of excavations in Egypt.

"At the end of the 5th dynasty and the beginning of the 6th dynasty, there was a conflict between two branches of the royal families."

The American University's Ikram added, "I assume Teti thought it would be a good plan to make his mother a pyramid."

Regardless of Teti's motivations, SCA director Hawass says the newfound pyramid is special because of its association with a female ruler.

"You can discover a tomb or a statue, but to discover a pyramid it makes you happy. And a pyramid of a queen—queens have magic."