.

American scientists claim to have found evidence that suggests Mars had a warm and wet climate which could have supported life some 3.5 billion years ago.

A team, led by planetary geologists at Brown University, found mounds of a mineral deposited on a volcanic cone less than 3.5 billion years ago that speak of a warm and wet past, and may preserve evidence of one of the most recent habitable microenvironments on the red planet.

Observations by the National Aeronautics and Space Administration's Mars Reconnaissance Orbiter enabled the researchers to identify the mineral as hydrated silica which can be dissolved, transported and concentrated by hot water or steam - a dead ringer that water was present at some time.

Best evidence yet

The mineral and the mounds' location on the flanks of a volcanic cone provide the best evidence yet on Mars for an intact deposit from a hydrothermal environment — a steam fumarole or a hot spring, said the researchers.

Such environments might have provided habitats for some of Earth's earliest life forms, they hoped.

“The heat and water required to create this deposit probably made this a habitable zone,” said J. R. Skok, lead author of the study, published in journal Nature Geoscience.

“If life did exist there, this would be a promising spot where it would have been entombed - a microbial mortuary, so to speak.”

Favourable climate

No studies have determined whether Mars has ever supported life, but this finding adds to accumulating evidence that at some times and in some places, Mars hosted favourable climate for microbial life.

The deposit is located in the sprawling, flat, volcanic zone known as Syrtis Major and was believed to have been left during the early Hesperian period, when most of Mars was already turning chilly and arid.

“Mars is just drying out,” Skok said, “and this is one last hospitable spot in a cooling, drying Mars.”

Concentrations of hydrated silica have been identified on Mars previously, including a nearly pure patch found by NASA's Mars Exploration Rover Spirit in 2007. However, this is the first found in an intact setting that clearly signals the mineral's origin.

“You have spectacular context for this deposit,” Skok said. “It's right on the flank of a volcano. The setting remains essentially the same as it was when the silica was deposited.”

Bright deposits

Observations by cameras on the Mars Reconnaissance Orbiter revealed patches of bright deposits near the summit of the cone, fanning down its flank, and on flatter ground in the vicinity.

The Brown researchers partnered with Scott Murchie, of Johns Hopkins University Applied Physics Laboratory, to analyse the bright exposures with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the orbiter.

Hydrated silica identified by the spectrometer in uphill locations, confirmed by stereo imaging, indicates that hot springs or fumaroles fed by underground heating created these deposits. Silica deposits around hydrothermal vents in Iceland are among the best parallels on Earth.

“The habitable zone would have been within and alongside the conduits carrying the heated water,” Murchie said.

The International Space Station -- which is coming up on a decade of continuous human habitation -- is a celebrated success in our species' quest to learn to live in space. Yet life in orbit has its serious trials, and mishaps along the way have proven just how much we still have to learn about being a spacefaring civilization.

In honor of Halloween, here are 10 ways space station living can become a little horror story:

10. Fingernails fall off

The spacesuit gloves astronauts wear while working outside the station during spacewalks have proven to be hazardous to their health.

A recent study found that about 10 percent of astronauts are victims of "fingernail trauma" from gloves, with a number of them losing a fingernail entirely because the glove pinched their fingers and reduced circulation.

Typically, the damage is worse the larger an astronaut's hand is. Maybe NASA should look for petite spaceflyers.

9. Weightless worries

Weightless living can have some pretty odd consequences without even going outside. Take, for example, the attack of the flying wasabi.

In March 2007 astronaut Sunita Williams was trying to squeeze some of the spicy green condiment onto her makeshift space sushi, when a squirt got loose, ultimately splattering the walls with wasabi and hiding stray droplets around the module.

It took a while to get the wasabi smell out after it had flown all over the place, Williams said at the time. And she had to forgo wasabi on future space meals, saying it was just "too dangerous."

8. Rough ride

While floating on the space station can be fun, getting to and from it can be a rough ride. Trips on the Russian Soyuz spacecraft, in particular, reportedly pack quite a punch of G forces.

"I've heard it described as a train wreck followed by a car crash followed by falling off your bike," NASA astronaut Tracy Caldwell Dyson said recently before she flew home from the station on one herself.

After she had experienced the trip, she said the rumors were dead on.

"It certainly didn't disappoint," Caldwell Dyson told SPACE.com after her return. "All the bangs, bells, whistles and sensations were there. The magnitudes of some things were a little surprising, but for the most part it was a pretty exciting ride."

7. Space diet of baby food

Though it's not just Tang and freeze-dried ice cream these days, food in space still leaves something to be desired.

Fresh fruit and vegetables are scarce, for example, and ground staples like bread are impractical because they leave crumbs, which in microgravity fly around everywhere instead of settling on the floor, and become a disaster to clean up. (Instead astronauts favor tortillas, which create fewer crumbs).

And astronauts tend to get sick of the same roster of re-heatable meals rotated on an eight-day schedule.

In the winter of 2004, however, an unmanned cargo ship due to deliver fresh food and supplies to the space station was delayed. In response, the crewmembers onboard – Expedition 10 commander Leroy Chiao of NASA and flight engineer Salizhan Sharipov of Russia – had to ration their meals.

The two ended up cutting their regular food consumption in half to conserve supplies, then making up for the lost calories by eating abundant desserts and candies. "It wasn't an unhealthy diet, but it wasn't an ideal diet either," Chiao said at the time.

6. Cramped quarters

While the station has grown considerably over the 10 years it's been permanently inhabited, many spaces are still a tight squeeze. And for the last year and a half, the normal crew size aboard the orbiting lab have been six, meaning what space there is has been shared by more bodies.

Sleeping can be particularly cramped inside an astronaut's "crew quarters" – essentially an alcove the size of a phone booth – and there are other hazards of catching some Zzz's in a free floating sleeping bag.

"During the night while you're sleeping, you might start drifting and end up somewhere you didn't intend to be in the first place," Canadian astronaut Julie Payette said in 2009.

Yet overall, the coziness of slumbering without gravity's incessant pull makes sleeping in space rather comfy, Payette said.

5. Hygiene hiccups

The lack of showers in space often puts a serious damper on the experience.

Microgravity makes it impossible to have a normal shower where water falls from a stream and falls docilely into a drain. Instead, astronauts on the International Space Station use a squirt gun that shoots out water and a wash cloth. They also have a special rinse-less shampoo to keep their hair clean.

"We wash like we would if we were on an expedition or a camping trip or something," Payette explained. "It works."

Still, who wants to keep that up for six months? Especially with the aforementioned tight living quarters!

4. Toilet troubles

One of the peskiest recurring problems on the station is the toilet situation.

There are two toilets on the space station – one in the Russian segment, and one in the United States modules. But both have been balky, breaking and requiring on-orbit plumbing jobs to get them working again.

Then there's the issue of what happens to the waste water – as of May 2009, urine is recycled into clean drinking water, and is also recycled into water for bathing and food preparation.

"It's sort of one of those horrible and fascinating kind of things. It's like, 'You're going to drink urine?'" said astronaut Sandra Magnus, who was living on the station when the urine recycling system was installed. "We're not, we're drinking processed water that started as urine."

3. Creaky bones

Beyond the daily nuisances, astronauts have to deal with serious health consequences from their time in orbit. One of the most significant of these is the effect on their bones.

A recent study found that astronauts' bone strength dips by at least 14 percent during a half-year stay in space. Other research indicates that an astronaut's bone mineral density can decrease by between 0.4 percent and 1.8 percent each month they are on the station, leading to greater risks of fractures and osteoporosis later in life.

While there is no complete fix for this problem, astronauts are diligent about bone-strengthening exercises while they're on the station, and undergo extensive rehabilitation once they're back on the ground to try to avoid possessing the bones of a 90-year-old.

2. Losing your lunch

Space sickness, too, can affect the best of 'em.

Acclimatizing to life in zero gravity, especially since no simulator can reproduce microgravity on the ground, takes time. It's not uncommon for astronauts to lose their lunch after liftoff before they even reach the space station.

And, to make matters worse, spewing chunks in space creates rather more of a mess than it would on Earth, since projectile vomit doesn't project toward the ground.

1. The loneliest number

Perhaps the hardest part of life in space is the feeling of isolation astronauts can get when they spend half a year removed from the whole planet, especially their friends and family. While astronauts can combat the loneliness by bonding with crewmates and making frequent calls home, they sometimes have to miss major life events back on Earth.

In December 2007, NASA astronaut Daniel Tani's mother died in a car accident while he was living on the space station. Tani had to grieve from more than 200 miles away in orbit, until he came back to Earth about two months later.

And in 2004, NASA astronaut Michael Fincke was forced to miss the birth of his second child, when his wife gave birth to daughter Tarali while he was serving a long-duration mission during the station's Expedition 9. He was able to meet his daughter four months later when he finally landed.

• Graphic: Inside and Out: The International Space Station
• Video: Astronaut Describes Riding Home on a Soyuz, Soyuz Landing Photos
• Space Station Life Has its Ups and Downs, Astronaut Says

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The views from this five-bedroom, two-bathroom home are, well, out of this world.

And for the past decade, not a day has passed when someone hasn't been able to gaze out at Earth streaming by 220 miles below.

Tuesday marks 10 years of humans permanently living and working aboard the International Space Station.

That will break the record of uninterrupted human presence in Earth orbit, eight days short of 10 years, by Mir, a Russian complex in orbit from 1986 to 2001.

"Once you realize what you're doing, then you're astonished by the fact that here you are, one of six people in space," said astronaut Tracy Caldwell Dyson, who lived for 188 days on the ISS. "It can make you emotional at times."

The station's first resident crew -- two Russians and an American -- opened the outpost for business Nov. 2, 2000, beginning human operations that continued despite system failures, the post-Columbia grounding of NASA's shuttle fleet and an old-fashioned malady, homesickness.

Three months into Expedition 1's four-month mission, NASA realized they had to make some adjustments: More time was allowed for speaking to loved ones back home, and the crew was encouraged to watch movies and listen to music they liked.

"That's what it's really like to live in space," said KSC Director Robert Cabana, who has flown into space four times on the shuttle but admits he regrets never having completed a long-duration flight aboard the station. "The shuttle is phenomenal, but those space station crews . . . ."

Sixty-four people have boarded the outpost for long-duration stays. In total, 196 explorers have visited -- not including seven space tourists, all buying seats onboard the Russian Soyuz.

Crews conduct scientific research -- the main purpose of the station -- but also have to be handy enough to repair everything from a malfunctioning toilet to a broken solar panel.

Earth is currently in a period of warming. Over the last century, Earth's average temperature rose about 1.1°F (0.6°C). In the last two decades, the rate of our world's warming accelerated and scientists predict that the globe will continue to warm over the course of the 21st century. Is this warming trend a reason for concern? After all, our world has witnessed extreme warm periods before, such as during the time of the dinosaurs. Earth has also seen numerous ice ages on roughly 11,000-year cycles for at least the last million years. So, change is perhaps the only constant in Earth's 4.5-billion-year history.

Scientists note that there are two new and different twists to today's changing climate: (1) The globe is warming at a faster rate than it ever has before; and (2) Humans are the main reason Earth is warming. Since the industrial revolution, which began in the mid-1800s, humans have attained the magnitude of a geological force in terms of our ability change Earth's environment and impact its climate system.

Since 1900, human population doubled and then double again. Today more than 6.5 billion people inhabit our world. By burning increasing amounts of coal and oil, we drove up carbon dioxide levels in the atmosphere by 30 percent. Carbon dioxide is a "greenhouse gas" that traps warmth near the surface.

Humans are also affecting Earth's climate system in other ways. For example, we transformed roughly 40 percent of Earth's habitable land surface to make way for our crop fields, cities, roads, livestock pastures, etc. We also released particulate pollution (called "aerosols") into the atmosphere. Changing the surface and introducing aerosols into the atmosphere can both increase and reduce cloud cover. Thus, in addition to driving up average global temperature, humans are also influencing rainfall and drought patterns around the world. While scientists have solid evidence of such human influence, more data and research are needed to better understand and quantify our impact on our world's climate system.

The first flight of the mission will be flying over a previous path over the Weddell Sea. Credit: Seelye Martin, University of Washington

After five days of weather delays, the NASA's IceBridge mission flew its first flight over the Antarctic polar caps yesterday.

The 12-hour flight was a great success, according to a report from Michael Studinger, one of the scientists on board the plane.

IceBridge is a six-year campaign to survey and monitor areas of Earth's polar ice sheets, glaciers and sea ice and how they are responding to climate change. The goal of this first flight of the winter Antarctic mission was to sample the conditions of sea ice in the Weddell Sea off the Antarctic Peninsula.

IceBridge's DC-8 plane, packed with scientists and equipments, traveled along a pair of lines from last year's mission that extend across the sea ice from the tip of the Antarctic Peninsula to south of Cape Norvegia, and back again. The flight path crossed the tip of the peninsula, proceeded to the eastern Weddell Coast, moved down the coast about 200 nautical miles (370 kilometers), and then transited back, where the sea ice is 1,500 feet (457 meters) thick.

One of the ways in which the plane measures the sea ice below is by Lidar (Light Detection And Ranging), an optical remote-sensing technology that measures properties of scattered light to find range and/or other information of a distant target.

"Lidars were successfully used to record the surface elevation of the sea ice floes, which are largely overlain by snow at this time of year. Wide-band radars were successfully used to estimate the thickness of the snow cover," Kenneth Jezek, the mission's science definition team co-leader from Ohio State University, told OurAmazingPlanet. "Knowledge about the snow thickness and also the surface elevation of the combined sea ice/snow cover column ultimately can be used to estimate the sea ice thickness."

A window view of Weddell Sea ice. Credit: NASA

Researchers who are part of the project but not on board the flights are also able to watch the progress of the flight in real time. Beyond the reports of the first mission's instruments working, there hasn't been much available to the researchers on the ground, but possibly in future missions sample data can accompany the feed.

"Right now, the flight and instrument crews have their hands full and are doing a great job!" Jezek said.

In a far-reaching restatement of goals for the nation’s space agency, NASA administrator Charles Bolden says President Obama has ordered him to pursue three new objectives: to “re-inspire children” to study science and math, to “expand our international relationships,” and to “reach out to the Muslim world.” Of those three goals, Bolden said in a recent interview with al-Jazeera, the mission to reach out to Muslims is “perhaps foremost,” because it will help Islamic nations “feel good” about their scientific accomplishments.

In the same interview, Bolden also said the United States, which first sent men to the moon in 1969, is no longer capable of reaching beyond low earth orbit without help from other nations.

Bolden made the statements during a recent trip to the Middle East. He told al-Jazeera that in the wake of the president’s speech in Cairo last year, the American space agency is now pursuing “a new beginning of the relationship between the United States and the Muslim world.” Then:

Later in the interview, Bolden discussed NASA’s goal of greater international cooperation in space exploration. He said the United States, more than 40 years after the first moon mission, cannot reach beyond earth’s orbit today without assistance from abroad:

Bolden’s trip included a June 15 speech at the American University in Cairo. In that speech, he said in the past NASA worked mostly with countries that are capable of space exploration. But that, too, has changed in light of Obama’s Cairo initiative. “He asked NASA to change…by reaching out to ‘non-traditional’ partners and strengthening our cooperation in the Middle East, North Africa, Southeast Asia and in particular in Muslim-majority nations,” Bolden said. “NASA has embraced this charge.”

“NASA is not only a space exploration agency,” Bolden concluded, “but also an earth improvement agency.”