NASA's Phoenix spacecraft has discovered evidence of past water at its Martian landing site and spotted falling snow for the first time, scientists reported Monday. Soil experiments revealed the presence of two minerals known to be formed in liquid water. Scientists identified the minerals as calcium carbonate, found in limestone and chalk, and sheet silicate. But exactly how that happened remains a mystery. "It's really kind of all up in the air," said William Boynton, a mission scientist at the University of Arizona at Tucson. A laser aboard the Phoenix recently detected snow falling from clouds more than two miles above its home in the northern arctic plains. The snow disappeared before reaching the ground.

A NASA probe has spotted hundreds of small surface fractures near Mars' equator that may have acted as underground natural plumbing to channel groundwater billions of years ago. Geologists compare the fractures in the sandstone rock deposits on Mars to features called deformation bands on Earth, which can arise from the influence of groundwater in the underground bedrock. The bands and faults have strong influences on groundwater movement on Earth, and seem to have played the same role on Mars. Other research has examined how surface water from rain or snow shaped the planet surface, but many agree that groundwater has an equally important influence. "Groundwater often flows along fractures such as these, and knowing that these are deformation bands helps us understand how the underground plumbing may have worked within these layered deposits," said Chris Okubo, a geologist with the U.S. Geological Survey in Flagstaff, Ariz. who headed up a new study of the Martian fractures.

The unanticipated discovery of a mineral in Mars’ arctic soil doesn’t rule out the possibility that the red planet could support life, scientists with the Phoenix lander said today. While cautioning that the discovery of perchlorate, an oxidizing agent found in rocket fuel, still had to be confirmed by more experiments, scientists with the UA-led Phoenix Mars Mission rejected speculation that the mineral’s presence killed the possibility of life on the planet. “These compounds are quite stable and don’t destroy organic compounds,” said Peter Smith, the UA’s lead scientist for the mission. “This is an important piece in the puzzle and it is neither good nor bad for life.” While perchlorate can be hazardous to some life forms on Earth, others use the molecules for life, including in remote arid desert regions. “The interesting thing is perchlorate is a relatively inert oxidant,” said Richard Quinn, a mission scientist. “There are some microbes that use it as an energy source.”

Little did Bucknell University geology professors Craig Kochel and Jeffrey Trop know, as they were working in Alaska, that they would soon predict one of the most important planetary observations ever made. The pair was in Alaska for an eight-day trip in July 2006, studying geological features and the processes that create them. As they studied photographs taken of the surrounding area, some features caught Kochel's eye. He thought they were strangely familiar, and then realized they reminded him of images he'd seen when working on the Viking missions to Mars in the 1970s. Kochel and Trop trekked to where the shots were taken overlooking a glacier. Spotting triangle-shaped landforms called "fans" sealed the deal: They looked strikingly similar to photographs taken of features on Mars.

If there ever was, is, or will be, life on Mars, it had better like eating asparagus. Nasa scientists who have reviewed the results of the first analysis of soil collected by the Phoenix Mars lander say they were 'flabbergasted' to find that it contained all the basic requirements, in terms of minerals and nutrients, to sustain life on the Red Planet. It was also much less acidic than the experts had expected - and suprisingly similar to garden dirt back on Earth. “There is nothing about the soil that would preclude life. In fact it seems very friendly,” said Professor Samuel Kounaves of Tufts University, the project’s lead chemist, told reporters in a telephone conference. “The soil you have there is the type of soil you have in your backyard,” he added. “You may be able to grow asparagus very well."

A new analysis of Martian soil data led by University of California, Berkeley, geoscientists suggests that there was once enough water in the planet's atmosphere for a light drizzle or dew to hit the ground, leaving tell-tale signs of its interaction with the planet's surface. The study's conclusion breaks from the more dominant view that the liquid water that once existed during the red planet's infancy came mainly in the form of upwelling groundwater rather than rain. To come up with their conclusions, the UC Berkeley-led researchers used published measurements of soil from Mars that were taken by various NASA missions: Viking 1, Viking 2, Pathfinder, Spirit and Opportunity. These five missions provided information on soil from widely distant sites surveyed between 1976 and 2006.

Were the northern plains of Mars submerged in a vast flood as recently as 20,000 years ago? Geologists claim to have found evidence of a recent volcanic eruption under the ice cap that could have created a wall of water 200 metres high and 35 kilometres wide. Signs of volcanic activity and flowing meltwater have been found before, but the new study links the two together with strong geological evidence, bolstering theories that water was the chief sculptor of the huge chasms in the northern martian ice cap. The flood, the researchers say, could have occurred within the past 10 million years and maybe as recently as 20,000 years ago — more evidence that Mars has not been a geological corpse since its wet and warm period billions of years ago.

Peering beneath the ice at the north pole of Mars has now revealed the red planet may be surprisingly colder than was thought. Any liquid water that might exist on Mars therefore might be hidden deeper than once suspected, closer to that world's warm heart, researchers suggested. An international team of scientists used the Mars Reconnaissance Orbiter to probe the north pole of the red planet with radar. The ice cap there goes about 1.2 miles deep (2 km) and is roughly the size of Pakistan at 310,000 square miles large (800,000 square km). These scans revealed the polar cap has up to four layers of ice rich in sand and dust, each separated by clearer sheets of nearly pure ice. Each dirty and clean layer is some 1,000 feet thick (300 meters).

A vanished glacier with a mysterious calling card suggests Mars went through many ice ages in its very recent past. A fresh look at images from the Mars Reconnaissance Orbiter indicates thick glaciers may have existed in the past 100 million years in the planet's equatorial region, but vanished after planetary wobbles changed the climate in certain areas. "We've gone from seeing Mars as a dead planet for three-plus billion years to one that has been alive in recent times," said Jay Dickson, a geologist at Brown University and lead author of the study. "[The finding] has changed our perspective from a planet that has been dry and dead to one that is icy and active."

There's a growing buzz in the astrobiology community that ancient hydrothermal springs may have been spotted on Mars. Thanks to the eagle-eyed work of Carlton Allen and Dorothy Oehler of NASA's Johnson Space Center, "spring-like" mounds have been found in Vernal Crater in Arabia Terra on the red planet. The high-powered zoom lens of NASA's Mars Reconnaissance Orbiter (MRO) has picked up the features - two possible ancient hydrothermal springs are viewed as light-toned, elliptical structures. The martian features have a striking similarity to spring mounds here on Earth, such as those in Dalhousie, Australia.

With its thin atmosphere and scant moisture, Mars is often largely cloud-free. But new observations reveal clouds of dry ice thick enough to cast significant shadows on the red planet. Dust storms are known to shroud vast swaths of Mars. Clouds have been photographed from the ground before, too. The new research finds that carbon dioxide, the main component of martian air, freezes into clouds so dense they dim the sun by about 40 percent. Frozen carbon dioxide is commonly called dry ice here on Earth.

The longstanding mystery of how oceans once formed on Mars could be solved by fire and brimstone. Specifically, researchers now suggest that ancient volcanoes could have released brimstone — now more commonly known as sulfur — that warmed up the red planet enough for liquid water oceans in the early days of Mars. These findings might also shed insight on the young Earth, including the origins of life, scientists added.

Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a natural—and not a human-induced—cause, according to one scientist's controversial theory. Earth is currently experiencing rapid warming, which the vast majority of climate scientists says is due to humans pumping huge amounts of greenhouse gases into the atmosphere. Mars, too, appears to be enjoying more mild and balmy temperatures. In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide "ice caps" near Mars's south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. "The long-term increase in solar irradiance is heating both Earth and Mars," he said.

NASA scientists have discovered what might form some of the weirdest landscapes on Mars, winding channels carved into the Martian surface that scientists have dubbed "spiders," "lace" and "lizard skin." The unusual landscape features form in an area of Mars' south pole called cryptic terrain because it once defied explanation. But new observations from NASA's Mars Reconnaissance Orbiter, presented here today at a meeting of the American Geophysical Union, bolster theories that the intricate patterns may be sculpted by springtime outbursts of carbon dioxide gas from underneath the frozen-carbon dioxide polar ice cap.

Clouds over Mars contain less water than previously thought, according to new research using simulated clouds in a lab here on Earth. The clouds under study are made of water ice, like some clouds on Earth, said Tony Colaprete of NASA's Ames Research Center. "However, they are forming at very cold temperatures, often below minus 100 degrees Celsius (minus 212 degrees Fahrenheit)," Colaprete said "What we have found in our laboratory studies is that it is much harder to initiate cloud formation at these cloud temperatures than what we thought."