Mars Express was able to accomplish what so many other spacecraft have tried and failed by using a SPICAM(2) spectrometer

The search for water on Mars has been ongoing for quite some time now, with Mars rovers like NASA's Spirit and Opportunity being two examples of those who have found clues that point to a once-tropical past on the dusty red planet billions of years ago.

Now, the European Space Agency's Mars Express spacecraft has discovered that Mars' atmosphere holds water vapor in a supersaturated state.

Mars Express was able to accomplish what so many other spacecraft have tried and failed by using a SPICAM(2) spectrometer. While other spacecraft have used tools that concentrate only on surface data, which only analyzes the horizontal component of the Martian atmosphere, SPICAM(2) utilizes solar occultation to observe the vertical component of the atmosphere, which is critical for understanding Mars' hydrological cycle. Solar occultation studies light from the Sun in Martian atmosphere during sunrise and sunset.

Supersaturation is the vapor of a compound that has a higher pressure than the vapor pressure of that compound. Earth's atmosphere is considered saturated because water vapor condenses when the temperature drops below dew point, and the atmosphere cannot contain any more moisture at that point. This excess water turns into a liquid around dust and particles that are suspended, causing precipitation, but sometimes the low availability of dust and particles can slow condensation and leave excess water vapor in its gaseous state. This is supersaturation.

As it turns out, supersaturation is common on Mars. In fact, Mars Express found that the levels of supersaturation on Mars were 10 times higher than those on Earth.

"This ability of water vapor to exist in a highly supersaturated state would, for example, allow to supply the southern hemisphere of Mars with water, far more efficiently than models currently predict," said Franck Montmessin, a researcher at the Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS, CNRS / UPMC / UVSQ).

This research could contribute to the overall understanding of the planet's low amount of water today as opposed to its abundance of water billions of years ago.

This study was published in Science.

The largest virus yet discovered has been isolated from ocean water pulled up off the coast of Chile.

Called Megavirus chilensis, it is 10 to 20 times longer than the average virus.

It just beats the previous record holder, Mimivirus, which was found in a water cooling tower in the UK in 1992.

Scientists tell the journal PNAS that Megavirus probably infects amoebas, single-celled organisms that are floating free in the sea.

The particle measures about 0.7 micrometers (thousandths of a millimetre) in diameter.

"It is bigger than some bacteria," explained Professor Jean-Michel Claverie, from Aix-Marseille University, Marseille, France.

For the first time, researchers have detected ocean-like water in a comet - new evidence supporting the theory comets delivered a significant portion of Earth's oceans.

"Life would not exist on Earth without liquid water, and so the questions of how and when the oceans got here is a fundamental one," says Ted Bergin, an astronomy professor at the University of Michigan. "It's a big puzzle and these new findings are an important piece."

The findings are reported in the journal Nature.

Bergin is a co-investigator on HiFi, the Heterodyne Instrument for the Infrared on the Hershel Space Observatory. With measurements from HiFi, the researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans. Both have similar D/H ratios. The D/H ratio is the proportion of deuterium, or heavy hydrogen, in the water. A deuterium atom is a hydrogen with an extra neutron in its nucleus.

A giant sea monster, the likes of the mythological kraken, may have swum Earth's ancient oceans, snagging what was thought to be the sea's top predators - school bus-size ichthyosaurs with fearsome teeth.

The kraken, which would've been nearly 100 feet (30 meters) long, or twice the size of the colossal squid, Mesonychoteuthis, likely drowned or broke the necks of the ichthyosaurs before dragging the corpses to its lair, akin to an octopus's midden, according to study researcher Mark McMenamin, a paleontologist at Mount Holyoke College in Massachusetts.

There is no direct evidence for the beast, though McMenamin suggests that's because it was soft-bodied and didn't stand the test of time; even so, to make a firm case for its existence one would want to find more direct evidence.

McMenamin is scheduled to present his work Monday (Oct. 10) at the annual meeting of the Geological Society of America in Minneapolis.

On December 12, 2010, something very unusual happened to asteroid Scheila. For a short period of time, its appearance changed dramatically and it even developed a comet-like tail. Now a group of international scientists headed by Fernando Moreno of the Instituto de Astrofísica de Andalucía in Granada, Spain have created a computer model which may explain this weird activity... an impact.

In results revealed October 7th in Nantes, France at the joint meeting of the European Planetary Science Congress and the American Astronomical Society's Division for Planetary Sciences, the team explained their theory of how this innocent asteroid may have been crashed into by a smaller object. Moreno and his team plotted the brightness curve of Scheila's newly developed "tail" - watching how it declined over a period of weeks. Their conclusion was that Scheila was either responsible for bumping into an uncatalogued object - or the object bumped into it causing a debris trail.

"The model we used involves a very large number of particles ejected from Scheila." explains Moreno. "We took into account gravity from the Sun, pressure radiation on the ejected particles, and Scheila´s gravity, which has a strong effect on the particles in its vicinity owing to its large mass."

An internal U.S. Department of Homeland Security document indicates that a controversial program designed to predict whether a person will commit a crime is already being tested on some members of the public voluntarily, CNET has learned.

If this sounds a bit like the Tom Cruise movie called Minority Report, or the CBS drama Person of Interest, it is. But where Minority Report author Philip K. Dick enlisted psychics to predict crimes, DHS is betting on algorithms: it's building a "prototype screening facility" that it hopes will use factors such as ethnicity, gender, breathing, and heart rate to "detect cues indicative of mal-intent."

The latest developments, which reveal efforts to "collect, process, or retain information on" members of "the public," came to light through an internal DHS document obtained under open-government laws by the Electronic Privacy Information Center. DHS calls its "pre-crime" system Future Attribute Screening Technology, or FAST.

"If it were deployed against the public, it would be very problematic," says Ginger McCall, open government counsel at EPIC, a nonprofit group in Washington, D.C.

Rare evidence of the long-held belief that humans are still evolving has been unearthed in the parish records of a French-Canadian island on the Saint Lawrence seaway, researchers say.

Ile aux Coudres is located 80 kilometers (50 miles) northeast of Quebec City. Between 1720 and 1773, 30 families settled there and the population reached 1,585 people by the 1950s.

Poring over church registers containing detailed records of dates of births, marriages and deaths, researchers found the age of women when they had their first child fell from about 26 to 22 years over 140 years from 1799 to just before 1940.

After discounting environmental and social factors, they concluded this substantial change from one generation to the next "largely occurred at the genetic level."

"It is often claimed that modern humans have stopped evolving because cultural and technological advancements have annihilated natural selection," says the study led by Emmanuel Milot at the University of Quebec in Montreal.

A computer virus has infected the cockpits of America's Predator and Reaper drones, logging pilots' every keystroke as they remotely fly missions over Afghanistan and other warzones.

The virus, first detected nearly two weeks ago by the military's Host-Based Security System, has not prevented pilots at Creech Air Force Base in Nevada from flying their missions overseas. Nor have there been any confirmed incidents of classified information being lost or sent to an outside source. But the virus has resisted multiple efforts to remove it from Creech's computers, network security specialists say. And the infection underscores the ongoing security risks in what has become the U.S. military's most important weapons system.

"We keep wiping it off, and it keeps coming back," says a source familiar with the network infection, one of three that told Danger Room about the virus. "We think it's benign. But we just don't know."

What toppled giant Uranus, the seventh planet from the sun, to its tilt is a long-standing puzzle. Scientists suspect it was left spinning on its side after a collision with an object about twice the size of Earth.

But that doesn't explain why Uranus's moons spin sideways, relative to their orbital planes, matching almost exactly their parent planet's 98-degree tilt.

Jupiter's spin axis, by comparison is tilted 3 degrees; Earth's, 23 degrees; Saturn and Neptune, 29 degrees.

The answer, suggests a team of scientists, is that Uranus was pummeled more than once. Computer models show a series of impacts by Earth-sized objects could have left Uranus on its side before its moons formed.

A single crash, the researchers say, would have left any moons accumulating from a cloud of materials surrounding Uranus spinning in the opposite direction from how they appear today.

The research has implications for understanding how the solar system -- and other planetary families beyond our solar system -- formed and evolved.

"Mars is not a dead planet -it undergoes climate changes that are even more pronounced than on Earth."

James Head, planetary geologist, Brown University

The prevailing thinking is that Mars is a planet whose active climate has been confined to the distant past. About 3.5 billion years ago, the Red Planet had extensive flowing water and then fell quiet - deadly quiet. It didn't seem the climate had changed much since. However, studies by scientists at Brown University have shown that Mars' climate has been much more dynamic than previously believed.

This high-resolution image above, taken by the Mars Reconnaissance Orbiter, shows the rock debris that Brown scientists believe was left by a glacier that rose at least one kilometer from the surrounding plain and flowed downward onto the canyon.

After examining this stunning high-resolution images taken by the Reconnaissance Orbiter, researchers documented for the first time that ice packs at least 1 kilometer (0.6 miles) thick and perhaps 2.5 kilometers (1.6 miles) thick existed along Mars' mid-latitude belt as recently as 100 million years ago. In addition, the team believes other images tell them that glaciers flowed in localized areas in the last 10 to 100 million years - a blink of the eye in Mars's geological timeline.

This evidence of recent activity means the Martian climate may change again and could bolster speculation about whether the Red Planet can, or did, support life.

"We've gone from seeing as a dead planet for three-plus billion years to one that has been alive in recent times," said Jay Dickson, a research analyst in the Department of Geological Sciences at Brown and lead author. "[The finding] has changed our perspective from a planet that has been dry and dead to one that is icy and active."