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Dead stars surrounded by fields of dust from pulverized asteroids may seem to make up a forbidding and ominous picture, but researchers who studied six such star systems say the dust should actually fuel the optimism of people who dream of finding extraterrestrial life. The dust’s composition suggests that rocky planets like our own Earth may be common in the universe, researchers say, which ups the chance that life as we know it has evolved somewhere out there.

The dust in question was found surrounding small, dense white dwarf stars. As stars like our own sun near the end of their life, they puff up into red giants that consume their innermost planets and jostle the orbits of outer planets and asteroids. Eventually the stars blow off their outer layers and shrink down into white dwarfs. Occasionally, a perturbed asteroid will wander too close to the white dwarf, whose gravity rips the rocky body to shreds, forming debris [SPACE.com].

That debris is what researchers studied with NASA’s Spitzer Space Telescope. By viewing the stars through a spectrograph, which separates out light from different wavelengths, the scientists were able to observe the telltale signatures of certain chemicals in the light. Since that starlight is passing through the film of the asteroid debris, the light picked up signatures of the asteroids’ composition, too [Wired News]. Lead researcher Michael Jura announced at the ongoing American Astronomical Society meeting that the composition of the asteroid dust was remarkably similar to that of the rocky planets in our solar system.

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Five years ago on Saturday, the Mars rover Spirit touched down on Mars in a bundle of airbags, beginning a saga of robotic exploration that has delighted NASA scientists and the public alike. The second rover, Opportunity, arrived on the other side of the planet a few weeks later, on January 21. Combined, the rovers have made more than 13 miles of tracks on Mars’ dusty surface and sent a quarter-million images back to Earth. Their instruments have uncovered evidence that Mars was once a far wetter and warmer place than the frigid, dusty world it is now [AP].

The rovers were designed to last at least 90 days on the Red Planet, but NASA had hopes that the robots would exceed their warranty and keep on trucking. However, few expected Spirit and Opportunity to last half a decade in the punishing conditions of Mars. As for what comes next, nobody really knows, says rover project manager John Callas: “We realise that a major rover component on either vehicle could fail at any time and end a mission with no advance notice, but on the other hand, we could accomplish the equivalent duration of four more prime missions on each rover in the year ahead” [BBC News].

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An exhaustive report on what happened in the crew cabin during the final moments before the space shuttle Columbia broke up over Texas in 2003 found numerous equipment flaws that failed to protect the astronauts from the extreme conditions they were abruptly exposed to during the disaster. But in somber tones, NASA’s report also acknowledged that “the breakup of the crew module … was not survivable by any currently existing capability” [CNN].

The mission was doomed when a chunk of foam broke away from an external fuel tank and struck the shuttle’s left wing during its launch; 15 days later, during reentry to the Earth’s atmosphere, superheated gases poured into the hole created and melted the shuttle’s structure. From the crew’s perspective, the shift from what appeared to be a normal descent on 1 February 2003, into disaster happened so fast that the astronauts didn’t even have time to close the visors on their helmets…. The crew cabin broke away from the ship and started spinning rapidly. Analysis of the wreckage indicated the crew members had flipped cockpit switches in response to alarms that were sounding. The astronauts had also reset the shuttle’s autopilot system, the report said [New Scientist].

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In a vote of confidence for the fledgling commercial space industry, NASA has awarded contracts that could total $3.5 billion to two companies that plan to build rockets and ferry supplies to the International Space Station. The companies, SpaceX and Orbital Sciences Corporation, could begin launches as soon as 2010 to help fill the gap between the space shuttle’s expected retirement and the introduction of NASA’s next-generation rocket, the Ares I. The companies beat out traditional NASA contractors like Boeing and Lockheed Martin to snag the contracts.

Experts say that giving a contract to the young company SpaceX is a particularly bold bet. SpaceX, the plan’s linchpin because it is intended to begin the service, carries a relatively short pedigree as a government contractor and can point to only one successful launch, after three failures, of a smaller version of its Falcon rocket intended to supply the space station. Orbital Sciences is an established, midsize aerospace contractor but lacks a proven track record for the revamped version of the Taurus rocket it will use to supply the station [The Wall Street Journal, subscription required].

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Three months ago 90 rubber duckies set out on a perilous adventure, sliding down deep holes in a Greenland ice sheet that were expected to carry them eventually out to the ocean. In an experiment designed to shed light on the gradual melting of Greenland’s glaciers due to global warming, the duckies were deposited into moulins (tubular holes) in the Jakobshavn Glacier in mid-September by Alberto Behar, a robotics expert at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The idea was that the ducks would float along the same channels that melt waters do, and wherever they emerged would reveal the path of the disappearing ice [Scientific American].

But thus far the researchers who have been eagerly awaiting news of the duckies’ arrival in the ocean have been disappointed, and they’re now putting out a loud call for sailors, fishermen, and cruise passengers to keep their eyes peeled for bobbing specks of yellow on the waves. The $2 ducks were chosen for their buoyancy and for their durability in low temperatures. Nasa is offering $100 to the first person who finds a duck. The toys are stamped with an email address and the word “reward” in three languages, including Inuit [Telegraph].

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Forty years ago today, a brave crew of NASA astronauts were approaching the moon’s orbit for the first time, in a risky mission that lifted the hearts of Americans in a troubled era. Apollo 8 blasted off on the morning of December 21, and eased into the moon’s orbit on Christmas Eve, when hundreds of millions of people tuned in to hear the astronauts describe their view and read from the Bible. To the public, the Apollo 8 mission was an antidote to all the toxic events that had subverted most of 1968, including the assassinations of Martin Luther King Jr. and Robert Kennedy, the eruption of inner-city rioting and the peak of American involvement in the Vietnam War [Chicago Tribune].

Apollo 8 wasn’t originally intended to go to the moon; it was scheduled to orbit Earth and test the new lunar landing vehicle. But the vehicle wasn’t ready, and the CIA was reporting that the Soviets were on the verge of sending their own manned expedition around the moon, so NASA decided to push ahead. It was a gutsy, dangerous decision, and not just because flying without a lunar lander meant that Apollo 8’s crew - Commander Frank Borman, James Lovell, and Bill Anders - would be stranded without a lifeboat if anything went wrong. Houston still didn’t have the software Apollo would need to navigate to the moon. And the huge Saturn V rocket required to launch a spacecraft beyond the Earth’s gravity was still being perfected, and had never been used on a manned flight. By today’s standards, the risks were unthinkable. Apollo’s program director, Chris Kraft, figured the odds of getting the crew home safely were no better than 50-50 [The Boston Globe].

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In another promising sign that primitive life could have once existed on the surface of Mars, researchers have found deposits of a mineral that suggest that the planet once had life-friendly bodies of liquid water. The mineral, carbonate, has previously been detected in only trace quantities on Mars, but new data from the Mars Reconnaissance Orbiter’s spectrometer shows deposits in a rock outcropping in a region of valleys called the Nili Fossae. Since acidic conditions can prevent carbonates from forming, the discovery suggests that the rocks were created in neutral-pH water that might have provided a cosy habitat for life [New Scientist].

Water ice currently exists on Mars, and over the past few years researchers have accumulated evidence of liquid lakes and streams in the planet’s distant past. Most evidence has pointed to a period when water on the planet’s surface formed clay-rich minerals, followed by a time of drier conditions, when salt-rich, acidic water affected much of the planet. These later conditions would have proven difficult for any Martian life — if it ever existed — to endure or to leave any traces for scientists to find. Because carbonates dissolve quickly in acid, finding them shows at least some areas of the planet escaped the acid bath [SPACE.com].

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NASA officials have long pronounced themselves ready to move on from the aging space shuttles, which could be retired as soon as 2010, but the incoming Barack Obama administration has raised new doubts about what the next step should be. Last week, news reports surfaced that Obama’s transition team was questioning NASA about alternatives to the Ares I rocket that is currently under development as the shuttle’s replacement, and now transition team members are reportedly considering using modified military rockets instead. No decision has been made and the concept raises major technical, funding and policy issues. But in recent weeks, the transition team assigned to [NASA] has been asking aerospace industry officials about the feasibility of such a dramatic shift in priorities [The Wall Street Journal].

The Ares I rocket is designed to bring the new Orion crew capsule to the International Space Station, and eventually back to the moon and on to Mars. Technical difficulties and budget problems have raised doubts about the program, but NASA officials have dismissed these issues as a normal part of the process, and have argued against a change in plans. NASA officials stressed that moving away from the current Ares rocket designs almost certainly would entail extra costs and lengthy delays in getting the shuttle replacement off the ground. With the first Ares 1 test flight tentatively scheduled for next summer, “going to completely different hardware would put a big gap” in the workforce focusing on rocket development, said Steve Cook, Ares program manager. “We would really be stepping backward” by deciding that the shuttle replacement could ride safely on an alternate rocket [The Wall Street Journal].

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The next robotic explorer in NASA’s ambitious Mars program will have to wait an extra two years before taking off towards the red planet, NASA officials announced yesterday. The Mars Science Laboratory was scheduled to lift off in the fall of 2009, but with unsolved issues with some of the spacecraft’s electrical motors … NASA officials no longer thought they could meet that schedule without rushing the testing program.“We’ve determined that trying for ‘09 would require us to assume too much risk, more than I think is appropriate for a flagship mission like Mars Science Laboratory,” Michael D. Griffin, NASA’s administrator, said [The New York Times].

Because Earth and Mars only draw near to each other every 26 months, the next possible launch window will come in 2011. The new delay is just the latest bit of bad news regarding the Science Lab, which has busted deadlines and budgets since the project was approved in 2006. The rover was initially expected to cost $1.6 billion, but the new delay will push costs up to about $2.3 billion, NASA officials said.

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When NASA’s Cassini spacecraft swooped past Saturn’s moon Enceladus last year, it got a close-up view of the water vapor and ice plumes that stream away from the small moon. After analyzing the data, researchers say the evidence suggests that the material in the plumes originates as liquid water trapped beneath the moon’s icy surface, which increases the possibility that microbial, extraterrestrial life could exist in the lakes. “We think liquid water is necessary for life and there is more evidence that there is liquid water there,” said lead researcher Candice Hansen…. Scientists are aware of only three places where liquid water exists near the surface of a planet or other body - Earth, Jupiter’s moon Europa and now Enceladus [Telegraph].

Researchers identified four distinct jets within the plume where the water vapor appears to be traveling faster than 1,300 miles per hour. Such high speeds imply that the jets are fed by pressurised water vapour that shoots through narrow openings - which act like rocket nozzles - in the moon’s icy surface. The simplest way to generate such pressures is by evaporating a reservoir of liquid water that lies close to the moon’s surface [New Scientist], researchers say.

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NASA engineers have finally tested an “interplanetary Internet” that could be crucial for future communications with rovers and astronauts exploring the moon, Mars, or other planets. NASA says the system would rely on probes and orbiters to serve as relay stations, or routers, to send communications around the solar system. The space agency has been working for 10 years on the project with Vint Cerf, one of the Internet’s key inventors and now chief Internet evangelist for Google [AP].

The protocols (the language computers use to speak to each other) used for our terrestrial Internet won’t work for deep space, because they assume that the network’s nodes will be connected continuously, and that messages will travel swiftly. But communication between objects in space are frequently disrupted by solar storms and obstructing planets, and sending a message from Earth to Mars can take up to 20 minutes. So engineers at NASA’s Jet Propulsion Laboratory worked with Cerf to come up with a new protocol, called Disruption-Tolerant Networking (DTN).

With the new communications design, each network node is designed to hold onto data packets, instead of discard them, until a destination path can be found. “The incentive to use Internet-like protocols over space links was to take advantage of automated routing,” [said NASA’s Leigh Torgerson]. “With standard space-link communications, the ground sends commands to spacecraft to tell it what time and what data to send. It’s very hands-on-intensive” [Computerworld].

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An enormous helium balloon floating about 24 miles above Antarctica has detected a mix of high-energy electrons so exotic that researchers say the particles must have been created by some fascinating process: They may have been formed when dark matter particles collided and annihilated each other, or else a surprisingly close astronomical object like a pulsar could be spitting the electrons at Earth.

Researchers can’t yet determine which answer is correct, but say the dark matter explanation is more exciting. 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 [National Geographic News]. If the research balloon did detect the signature of dark matter through the particles left over from collisions, it would be the closest researchers have ever gotten to seeing the mysterious stuff.

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In an unusual moment of klutziness, spacewalking astronaut Heide Stefanyshyn-Piper let a tool kit slip from her grasp while she was working outside the International Space Station yesterday, and watched helplessly as it drifted away into deep space. “Oh, great,” said a dismayed Stefanyshyn-Piper, a veteran of two spacewalks in 2006, as she watched the bag float away [Florida Today].

The mishap occurred during the first of four spacewalks scheduled to be completed during the visit from the Endeavour space shuttle crew. The tool kit made its escape while Stefanyshyn-Piper and her colleague Steve Bowen were greasing a rotary joint on the station’s giant starboard solar array system. The joint has been unable to automatically point the solar wings toward the Sun for maximum energy production for over a year. Just as she was finishing up the job, the tool bag became untethered from a larger kit case and floated away along with a pair of grease guns, wipes and a putty knife. She reached out, but to no avail [BBC News].

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New data from NASA’s Mars Odyssey orbiter supports the long-debated theory that Mars once (or twice) had vast frozen oceans on its surface. The location of certain mineral deposits suggests massive erosion and ancient shorelines. A group of researchers now believes Mars had at least two oceans - one about three and a half billion years ago that was 20 times the size of the Mediterranean and a smaller one about two billions years ago. “These were not like the oceans we know,” says [researcher Victor] Baker. “These were transient bodies that existed long enough to accumulate sediment”, but were not present for billions of years of geologic history, as Earth’s oceans have been [New Scientist].

The Mars Odyssey orbiter identified the mineral deposits using a gamma-ray spectrometer, which can detect elements a third of a metre below Mars’s surface. It found enriched potassium, thorium and iron, lying in shoreline-type patterns, where researchers already suspected water used to lie [Canwest News Service]. Until now, however, their suspicions were mainly based on geographical features such as smooth plains surrounded by higher, more rugged terrain. The new data, to be published in Planetary and Space Science, shows minerals heavily concentrated in the soil below the proposed shoreline and less concentrated above, suggesting erosion of sediments into a large body of water. But study coauthor James Dohm says the new evidence isn’t a smoking gun: “It’s consistent with this ocean potential - it doesn’t confirm it, necessarily,” Dohm said. “I think it’s a significant piece of the puzzle” [Tucson Citizen].

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The space shuttle Endeavour docked with the International Space Station yesterday, bringing almost seven tons of supplies and a crew that’s determined to give the cramped station a thorough renovation. After the hatch opened, the astronauts floated weightlessly through a tunnel and into the welcoming arms of their colleagues aboard the $100 billion station. “We understand that this house is in need of an extreme makeover and that you are the crew to do it,” station commander Mike Fincke said. “Welcome to space” [Reuters].

The Endeavour crew brought up a host of home improvements that will allow the space station to support three additional crew members: The cargo includes a second kitchen module, and extra bathroom, two sleeping cabins and exercise gear. Other new equipment will provide both creature comforts and the necessities of life: the crew will soon install a space cooler so station astronauts can have cold drinks for the first time in the eight years astronauts have lived aboard. Endeavour is also toting a new water recycling system designed to collect astronaut urine, sweat and other wastewater into drinkable water [SPACE.com].

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