An oxygen atmosphere has been found on Saturn's second largest moon, Rhea, astronomers announced Thursday - but don't hold your breath for colonization opportunities.

For one thing, the 932-mile-wide (1,500-kilometer-wide), ice-covered moon is more than 932 million miles (1.5 billion kilometers) from Earth. For another, the average surface temperature is -292 degrees Fahrenheit (-180 degrees Celsius).

And at less than 62 miles (100 kilometers) thick, the newfound oxygen layer is so thin that, at Earthlike temperatures and pressure, Rhea's entire atmosphere would fit in a single midsize building.

During the Vietnam War, the U.S. Air Force laced the skies over North Vietnam and parts of Laos with small quantitites of aerosols designed to amplify the intensity of rainfall patterns by enhancing the density of clouds. The operation, known as "Operation Popeye," involved flying more than 2,602 U.S. cloud-seeding missions from Udorn Royal Thai Air Force Base over the course of several years. The effort apparently succeeded in flooding major Viet Cong supply routes and denying the use of trails and roads by extending the monsoon season over North Vietnam.

When reports of Operation Popeye surfaced in the media, Congress held hearings, the United Nations created a convention banning future military use of weather modification technologies and the nascent field of weather modification appeared to go the way of the passenger train - until recently.

The explorer, Christopher Columbus, was the son of a Polish king living in exile in Madeira and hid his royal roots to protect his father, a new book claims.

A Portuguese historian believes he has solved the 500 year-old mystery of the adventurer's true identity after a thorough investigation of medieval documents and chronicles.

The origins of the man who discovered the Americas has long been a subject of speculation.

Contemporary accounts named his birth place as the Italian port of Genoa to a family of wool weavers but over the centuries it has been claimed that he was a native of Greece, Spain, France, Portugal and even Scotland.

Others claimed his origins were hidden because he was Jewish or secretly working as a double agent for the Portuguese royal family.

But the latest theory suggests that the great navigator, who died in 1506 after four voyages to the New World, was in fact of royal blood: the son of King Vladislav III who was supposedly slain in the Battle of Varna in 1444.

They are at the very edge of current U.S. technological capabilities; one is a supposedly mothballed technology test-bed, the other a super-secret space plane that is currently on orbit - but set to land soon. They are the X-planes, experimental spacecraft that are proving out concepts and capabilities whose beginnings can be traced to the dawn of the space age.

It would appear from amateur observers on the ground that the secretive U.S. Air Force X-37B space plane - will be landing soon. This prediction is based off the fact that the craft is dropping in altitude and the more basic fact that it is nearing the limit of its orbital capabilities and has to return to terra firma. According to the U.S. Air Force, the X-37B can remain on orbit for around nine months or 270 days at maximum, this means that the craft should be landing sometime in the middle of January.

The X-37B or Orbital Test Vehicle (OTV) lifted off from Cape Canaveral Air Force Station in Florida on Apr. 22, atop an Atlas V rocket. Not much is known after launch due to a media blackout imposed by the U.S. Air Force.

Pity poor Leif Ericsson. The Viking explorer may well have been the first European to reach the Americas, but it is a certain Genoan sailor who gets all the glory. Thanks to evidence that has until now consisted only of bare archeological remains and a bunch of Icelandic legends, Ericsson has long been treated as a footnote in American history: no holiday, no state capitals named after him, no little ditty to remind you of the date of his voyage. But a group of Icelandic and Spanish scientists studying one mysterious genetic sequence - and one woman who's been dead 1,000 years - may soon change that.

Ten years ago, Agnar Helgason, a scientist at Iceland's deCODE Genetics, began investigating the origin of the Icelandic population. Most of the people he tested carried genetic links to either Scandinavians or people from the British Isles. But a small group of Icelanders - roughly 350 in total - carried a lineage known as C1, usually seen only in Asians and Native Americans. "We figured it was a recent arrival from Asia," says Helgason. "But we discovered a much deeper story than we expected."

Helgason's graduate student, Sigridur Sunna Ebenesersdottir, found that she could trace the matrilineal sequence to a date far earlier than when the first Asians began arriving in Iceland. In fact, she found that all the people who carry the C1 lineage are descendants of one of four women alive around the year 1700. In all likelihood, those four descended from a single woman. And because archeological remains in what is Canada today suggest that the Vikings were in the Americas around the year 1000 before retreating into a period of global isolation, the best explanation for that errant lineage lies with an American Indian woman: one who was taken back to Iceland some 500 years before Columbus set sail for the New World in 1492.

As the eurozone continues to wobble, new analysis of countries' economic interconnectedness finds that some of the countries with the greatest potential to cause a global crash have surprisingly small gross domestic production.

Using data from Bureau Van Dijk - the company information and business intelligence provider - to assess the reach and size of different countries' economies, and applying the Susceptible-Infected-Recovered (SIR) model, physicists from universities in Greece, Switzerland and Israel have identified the twelve countries with greatest power to spread a crisis globally.

The research published today, Thursday 25 November 2010, in New Journal of Physics (co-owned by the Institute of Physics and German Physical Society), groups Belgium and Luxembourg alongside more obviously impactful economies such as the USA in the top twelve.

What Einstein called his worst mistake, scientists are now depending on to help explain the universe.

In 1917, Albert Einstein inserted a term called the cosmological constant into his theory of general relativity to force the equations to predict a stationary universe in keeping with physicists' thinking at the time. When it became clear that the universe wasn't actually static, but was expanding instead, Einstein abandoned the constant, calling it the '"biggest blunder" of his life.

But lately scientists have revived Einstein's cosmological constant (denoted by the Greek capital letter lambda) to explain a mysterious force called dark energy that seems to be counteracting gravity - causing the universe to expand at an accelerating pace.

A new study confirms that the cosmological constant is the best fit for dark energy, and offers the most precise and accurate estimate yet of its value, researchers said. The finding comes from a measurement of the universe's geometry that suggests our universe is flat, rather than spherical or curved.

At the opening of his legendary 1960s TV anthology "The Twilight Zone," writer Rod Serling spoke of an eerie place between "light and shadow." The dim outer periphery of our solar system is a gravitational twilight zone when drifters from other stars mingle with lost solar system debris, according to a recent study.

At a distance of roughly six trillion miles from the sun an unknown number of ancient comet nuclei -- each just a few miles across -- drift at temperatures near absolute zero. When gravitationally perturbed they fall toward the inner solar system like apples shaken from a tree. At least we think they are there, based on the random direction and frequency at which comets dive-bomb the inner solar system.

This hypothetical region is named the Oort cloud after mid-20th century Dutch astronomer Jan Oort, who first proposed such a twilight region to explain what seemed to be a hidden reservoir of comets.

But a sexier name would be the "Alien Comet Zone." Did I say alien? Yes, because this primeval deep freezer may contain comets that were gravitationally snatched from other stars.

Date: November 4, 2010

The twentieth anniversary of an unusual and highly original case within Spanish cryptozoology took place a few months ago. In June 1990, a giant bird decided to frighten - with its imposing presence and unpleasant crowing - a sizable number of Barcelona's residents.

What was extraordinary, aside from the apparition in itself, was the way it became known through a series of letters to the editor of a renowned Spanish newspaper. We must bear in mind that this phenomenon goes beyond the purely cryptozoological to go into the field of anthropology or social psychology.

On the morning of June 10, 1990, readers of Barcelona's La Vanguardia had the chance to read a brief missive sent to the paper's editor by Pere Carbó, a resident of the city. The anonymous citizen said: "I cannot help but to make known my surprise at this unusual event: on the evening 28 May, some residents of the Les Corts district were awakened by the unbearable crowing of a bird. It wasn't just any bird. Our astonishment was immense when we stepped out to the balcony to see the black silhouette of a bird of tremendous size. It perhaps measured between 3 and 5 meters, and I am not exaggerating. Numerous residents saw it and numerous comments were made the next day. We assume that others must have seen it other neighborhoods. What was it? And what's stranger still, why hasn't it been mentioned in the press?"

The far side of the sun is alive with activity. On Nov. 26th, NASA's twin STEREO spacecraft and the Solar and Heliospheric Observatory (SOHO) observed two farside coronal mass ejections (CMEs) billowing into space. This one came from old sunspot 1126, located just over the sun's southwestern horizon:

Click HERE to play a 3 MB gif animation.

Hours later, a second CME followed, but not from the same blast site. The second CME came from an active region near the sun's anti-Earth point, almost directly opposite our planet on the solar farside. If Earth were on the other side of the sun, we would be be expecting bright auroras from the impact of these clouds. Instead, the alert is for "all quiet." Nothing major is heading our way.

The farside active regions that produced these eruptions will turn to face Earth in 7 to 14 days. Will they remain active that long? Stay tuned for updates.