2013년 1월 31일 목요일

NASA to Launch World's Largest Solar Sail in 2014

The largest solar sail ever constructed is headed for the launch pad in 2014 on a mission to demonstrate the value of "propellantless propulsion"— the act of using photons from the sun to push a craft through space.
Dubbed Sunjammer, the giant solar sail measures about 124 feet (38 meters) on a side and boasts a total surface area of nearly 13,000 square feet (1,208 square m, or one-third of an acre). The project is under the wing of NASA's Space Technology Program, within the agency's Office of the Chief Technologist.
NASA has contracted with a team of high-tech "solar sailors" at L'Garde Inc. of Tustin, Calif., to build Sunjammer.
L'Garde is no newcomer to novel space structures. The company has worked with the space agency on several projects, including the creation of inflatable structures for radio frequency antennas and solar arrays. In 1996, the company flew the Inflatable Antenna Experiment (IAE) aboard the space shuttle Endeavour's STS-77 mission.
Programmatic milestone
"We took the name Sunjammer from an Arthur C. Clarke short story, a fictional yacht race in the heavens using solar sails," said Nathan Barnes, L'Garde's chief operating officer and executive vice president, as well as Sunjammer's project manager. Permission to use the name came from the Clarke estate, he told SPACE.com.
Work on Sunjammer this year includes a programmatic milestone — a critical design review — along with a variety of ground demonstration tests and qualification of components, Barnes said. The flight of the solar sail, he said, is set for the end of 2014, to be sent spaceward atop a SpaceX Falcon 9 rocket.
"With this sail, we’re targeting our end goal somewhere in the neighborhood of 1,864,114 miles (3 million kilometers) distance from the Earth," Barnes said.
A number of test objectives are to be checked off within the first couple months of flight, he added. These include deployment of the sail, demonstration of vector control using sail-tipped vanes, navigation with accuracy and, finally, maintenance of the spacecraft's position at a gravitationally stable location called Earth-Sun Lagrange Point 1.
Sunjammer won't be the world's first solar sail mission. NASA launched NanoSail-D, whose sail covered just 100 square feet (9.3 square m), in November 2010. And Japan's Ikaros probe deployed its solar sail in June 2010, becoming the first craft ever to cruise through space propelled only by sunlight.
Neat, clever, exotic orbits
Sunjammer is potentially applicable to an advanced space weather warning system, which could provide more timely and accurate notice of solar flare activity.
The U.S. National Oceanic and Atmospheric Administration is collaborating with NASA and L’Garde on the upcoming demonstration flight, which will cruise to a spot that provides an interesting view of the sun.
"It will be us flying to a place that a customer actually wants to fly a solar sail to," Barnes said. "There are neat, clever, exotic orbits you can do with the solar sail that would permit viewing different portions of the sun that we can’t normally." 
One-quarter the size of a football field, Sunjammer will produce a whopping maximum thrust of approximately 0.01 newton, Barnes said — roughly equivalent to the weight of a sugar packet.
Thinner sail
Kapton is the solar sail material of choice. The mission team worked with chemical company DuPont to produce a special layer of Kapton for Sunjammer just 5 microns thick.
"Thinner is always better," Barnes said.
When collapsed, the Sunjammer solar sail is the size of a dishwasher and weighs just 70 pounds (32 kilograms).
There are a number of control techniques involved in successfully unfurling the sail, said Billy Derbes, L’Garde’s chief engineer for Sunjammer.
"The highest risk is in the deployment," Derbes said. A camera attached to the sail will capture the unfurling process.

Game-changing capabilities
NASA is keen to infuse solar sail technology into other potential game-changing mission capabilities.
Barnes said that possibilities include the collection and removal of orbital debris, deorbiting spent satellites, providing a direct communications link to Earth’s south pole, as well as for deep space propulsion.
Barnes said nongovernment, entertainment-oriented uses of solar sails are also being explored by L’Garde.
"All space travel right now is limited by expendables," Derbes said. "If you show a technology not limited by expendables — and Kapton is a long-lasting film material — what new applications will people think up? We’re opening up a whole new kind of thinking about how you do things in space."
'Star Trek' passengers
Also to fly onboard Sunjammer are the cremated remains of individuals, a service provided by Celestis, Inc., an affiliate company of Space Services, Inc., a Houston-based aerospace firm.
Celestis flight capsules and modules will be carried by Sunjammer on its voyage through deep space. Already part of that payload are the ashes of "Star Trek" creator Gene Roddenberry and his wife Majel Barrett Roddenberry, often called the "first lady" of the sci-fi series.
"Celestis is pleased to offer our first-ever Voyager deep space memorial spaceflight aboard the Sunjammer mission," said Celestis CEO Charles Chafer.
"Since 1997, Celestis has conducted a dozen memorial spaceflights, and this solar sail mission will mark our most ambitious flight ever. We are excited to be a part of the Sunjammer team," Chafer told.

'Green' space propulsion
Sunjammer’s success is the key to enabling several science and exploration missions that can only be accomplished with a solar sail, said Les Johnson, deputy manager of the Advanced Concepts Office at NASA's Marshall Space Flight Center in Huntsville, Ala.
Along with better sun-watching and warning tasks, NASA recently studied the use of a solar-sail-propelled spacecraft for visiting multiple near-Earth asteroids (NEAs), Johnson said.
"We found that a Sunjammer-derived sail could visit up to six NEAs within six years of being launched. This would be impossible with chemical rockets and might not be achievable by electric propulsion. And it’s all because the sail uses no propellant … deriving its thrust from sunlight, making it a very ‘green’ space propulsion system," he said.
Johnson is co-editor with Jack McDevitt of "Going Interstellar" (Baen Books, 2012), a unique blend of science fact and science-fiction writings on interstellar voyaging.
"For me, I’m most excited about using a solar sail unfurled close to the sun, inside the orbit of Mercury, and using the increased solar pressure there to accelerate a large solar sail to speeds that will allow it to reach well beyond the edge of the solar system and into interstellar space within my lifetime," Johnson said. 
Doing so, Johnson said, "would be the first ‘baby step’ in a series of increasingly large sails that might one day enable us to reach the stars. This is one of the few ways nature has provided for us to travel between the stars."

Source of Article : space.com

2013년 1월 20일 일요일

Celestial Wonder Looks Uncannily Like a Manatee

A watery-looking nebula in deep space is being renamed after the sea creature it strongly resembles: a manatee.
The nebula is the leftovers from a star that died in a supernova explosion about 20,000 years ago. Before it died, the giant star puffed out its outer gaseous layers, which now swirl in green-and-blue clouds around the dead hulk of the star, which has collapsed into a black hole.
Known officially as W50, the celestial object is being dubbed the Mantee Nebula  by the National Radio Astronomy Observatory (NRAO), during a ceremony today (Jan. 19) at the Florida Manatee Festival in Crystal River, Fla. The NRAO will also unveil a new photo of the nebula taken by the Very Large Array (VLA) radio telescope network in New Mexico.
"When the VLA's giant W50 image reached the NRAO director's office, Heidi Winter, the director's executive assistant, saw the likeness to a manatee, the endangered marine mammals known as 'sea cows' that congregate in warm waters in the southeastern United States," NRAO officials wrote in a statement."

2013년 1월 16일 수요일

Tiny Solar Activity Changes Affect Earth's Climate

Even small changes in solar activity can impact Earth's climate in significant and surprisingly complex ways, researchers say.
The sun is a constant star when compared with many others in the galaxy. Some stars pulsate dramatically, varying wildly in size and brightness and even exploding. In comparison, the sun varies in the amount of light it emits by only 0.1 percent over the course of a relatively stable 11-year-long pattern known as the solar cycle.
Still, "the light reaching the top of the Earth's atmosphere provides about 2,500 times as much energy as the total of all other sources combined," solar physicist Greg Kopp at the University of Colorado told. As such, even 0.1 percent of the amount of light the sun emits exceeds all other energy sources the Earth's atmosphere sees combined, such as the radioactivity naturally emitted from Earth's core, Kopp explained.
To learn more about how such tiny variations in solar energy might impact terrestrial climate, the National Research Council (NRC) convened dozens of experts in many fields, such as plasma physics, solar activity, atmospheric chemistry, fluid dynamics and energetic particle physics.

Sun's role in Earth's climate
Many of the ways the scientists proposed these fluctuations in solar activity could influence Earth were complicated in nature. For instance, solar energetic particles and cosmic rays could reduce ozone levels in the stratosphere. This in turn alters the behavior of the atmosphere below it, perhaps even pushing storms on the surface off course. 
"In the lower stratosphere, the presence of ozone causes a local warming because of the breakup of ozone molecules by ultraviolet light," climate scientist Jerry North at Texas A&M University told.
When the ozone is removed, "the stratosphere there becomes cooler, increasing the temperature contrast between the tropics and the polar region. The contrast in temperatures in the stratosphere and the upper troposphere leads to instabilities in the atmospheric flow west to east. The instabilities make for eddies or irregular motions."
These eddies feed the strength of jet streams, ultimately altering flows in the upper troposphere, the layer of atmosphere closest to Earth's surface. "The geographical positioning of the jets aloft can alter the distribution of storms over the middle latitudes," North said. "So the sun might have a role to play in this kind of process. I would have to say this would be a very difficult mechanism to prove in climate models. That does not mean it may not exist — just hard to prove."
In addition, climate scientist Gerald Meehl at the National Center for Atmospheric Research and his colleagues suggest that solar variability is leaving a definite imprint on climate, especially in the Pacific Ocean.
When researchers look at sea surface temperature data during sunspot peak years, the tropical Pacific showed a pattern very much like that expected with La Niña, a cyclical cooling of the Pacific Ocean that regularly affects climate worldwide, with sunspot peak years leading to a cooling of almost 1 degree Celsius (1.8 degrees Fahrenheit) in the equatorial eastern Pacific. In addition, peaks in the sunspot cycle were linked with increased precipitation in a number of areas across the globe, as well as above-normal sea-level pressure in the mid-latitude North and South Pacific.
"The Pacific is particularly sensitive to small variations in the trade winds," Meehl said. Solar activity may influence processes linked with trade wind strength.
Sun's impact on history
Scientists have also often speculated whether the Maunder Minimum, a 70-year dearth of sunspots in the late 17th to early 18th century, was linked with the coldest part of the Little Ice Age, during which Europe and North America experienced bitterly cold winters. This regional cooling might be linked with a drop in the sun's extreme ultraviolet radiation. In fact, the sun could currently be on the cusp of a miniature version of the Maunder Minimum, since the current solar cycle is the weakest in more than 50 years.
"If the sun really is entering an unfamiliar phase of the solar cycle, then we must redouble our efforts to understand the sun-climate link," said researcher Lika Guhathakurta at NASA's Living with a Star Program, which helped fund the NRC study.
Although the sun is the main source of heat for Earth, the researchers note that solar variability may have more of a regional effect than a global one. As such, solar variability is not the cause of the global warming seen in recent times.
"While the sun is by far the dominant energy source powering our climate system, do not assume that it is causing much of recent climate changes. It's pretty stable," Kopp said. "Think of it as an 800-pound gorilla in climate — it has the weight to cause enormous changes, but luckily for us, it's pretty placidly lazy. While solar changes have historically caused climate changes, the sun is mostly likely responsible for less than 15 percent of the global temperature increases we've seen over the last century, during which human-caused changes such as increased greenhouse gases caused the majority of warming."
Tracking the sun
In the future, researchers suggested that to better understand how solar variability might affect the Earth, a future space observatory might include a radiometric imager. Such a device could essentially map the surface of the sun and reveal the contributions of each of its surface features to the sun's luminosity.
The solar disk is dotted by dark sunspots and bright magnetic areas known as faculae. Sunspots tend to vanish during low points in the solar cycle, and a radiometric imager could help reveal the links between prolonged spotlessness on the sun and Earth's climate.
Ancient signals of climate such as tree rings and ice cores might also help shed light on the link between the sun and climate. Since variations in Earth's magnetic field and atmospheric circulation might disrupt this evidence on Earth, a better long-term record of solar radiation might lie in the rocks and sediments of the moon or Mars, researchers added.
The scientists detailed their findings Jan. 8 in a report, "The Effects of Solar Variability on Earth's Climate," issued by the National Research Council.

Source of Article : space.com

Smoke-Black Space Cloud Hides Baby Stars in Amazing Photo

A jaw-dropping new photo from a telescope in South America has revealed a smoke-black cloud in deep space hiding a bustling nursery of baby stars.
The new image, captured by a telescope at the European Southern Observatory in Chile, is the best view ever of the dark space cloud Lupus 3. The cosmic cloud is about 600 light-years from Earth in the constellation Scorpious (The Scorpion).
The observatory released a wide-view and video tour of the Lupus 3 space clous and a dazzling bright star cluster in addition to the close-up photo.

"At first glance, these two features could not be more different, but they are in fact closely linked," ESO officials said in an image description today (Jan. 16).  
As the denser regions of the cloud contract under their own gravity and heat up, they blaze up into newborn stars whose light is initially blocked by the surrounding gas. But as stars grow hotter over time, their stellar winds sweep away the obstructing gas so that they emerge as bright beacons similar to those in the star cluster near Lupus 3, ESO officials explained.

"The bright stars right of the center of this new picture form a perfect example of a small group of such hot young stars," they added. "Some of their brilliant blue light is being scattered off the remaining dust around them."
Two of the brightest stars in the cluster can be seen easily with a small telescope, and are likely less than 1 million years old, according to an image description.

The new photo of Lupus 3 and its neighboring star cluster was snapped by the MPG/ESO 2.2-meter telescope at ESO's La Silla Observatory high up in Chile's Atacama Desert. It covers a visible field about 5 light-years across.
ESO officials said the Lupus 3 space cloud is likely similar to the star nursery that gave birth to Earth's sun more than 4 billion years ago.

Source of Article : space.com

Inside NASA's Deal for an Inflatable Space Station Room

A new deal between NASA and a commercial spaceflight company to add a privately built module to the International Space Station could lead to future uses of the novel space technology beyond low-Earth orbit, space agency and company officials say.
NASA will pay $17.8 million to Bigelow Aerospace of North Las Vegas to build an inflatable module, test it and prep it for flight. The Bigelow Expandable Activity Module (BEAM) is to be launched around the summer of 2015.
The space agency and Bigelow officials provided details of the contract in a Las Vegas briefing today (Jan. 16).
The new inflatable BEAM will be launched to the International Space Station by a Falcon 9 rocket built by another private spaceflight company, California-based SpaceX. The module will be cocooned inside the unpressurized cargo hold of SpaceX's Dragon capsule atop the Falcon 9. NASA has already purchased the launch of the SpaceX Falcon under a separate Commercial Resupply Services contract.
The module will be installed on an open berth of the station's Node 3 connecting module using a robotic arm. Once it is attached, the inflatable room will be activated by station astronauts, adding to the volume of orbiting laboratory.

An inflatable space room
The module is cylindrical, weighs roughly 3,000 pounds (1,360 kilograms) and is about 13 feet (4 meters) long and 10.5 feet (3.2 m) wide.
Bigelow Aerospace's founder and president is Robert Bigelow, a Las Vegas-based general contractor, real estate tycoon, hotel businessman and developer. Since 1999, his company has been focused on creating affordable inflatable space habitats for national space agencies and corporate clients.
In 2006 and 2007 the firm launched orbiting prototypes of its expandable habitat technology, Genesis 1 and Genesis 2. Work is ongoing within Bigelow Aerospace on BA 330 modules, structures that offer 12,000 cubic feet (330 cubic meters) of internal space.
Michael Gold, director of Washington, D.C., operations and business growth for Bigelow Aerospace LLC, based in Chevy Chase, Md., said: "With Genesis 1 and 2, Bigelow Aerospace showed the world that it can achieve escape velocity from high costs. We're going to do this again with the BEAM, bringing both innovation and a vital demonstration of affordability to the crown jewel of NASA's human spaceflight program, the International Space Station."
A technology test
At this time, NASA's planned use of the BEAM is for technology demonstration, to validate experimental expandable habitat technology and let the space agency become more familiar with it, Gold told.
"I'm told the BEAM will be acoustically the quietest location aboard the station, due to the non-metallic nature of the structure," he said.
NASA's interest in the module for the International Space Station was first by this reporter in January 2011 — so why the long glide path, some two years, for the project to become a reality?
In actuality, the program "moved forward with relative alacrity," Gold responded.
"The ISS is the pinnacle of the human spaceflight program. NASA went through a thorough amount of analysis prior to agreeing about BEAM … Analysis and study does take time," Gold said. "It demonstrates the attention and commitment to safety and quality that both NASA and Bigelow Aerospace have."
BEAM bonus in space
For Bigelow, there is another bonus from having BEAM  attached to the space station: the chance to generate more business.
"Many in the foreign community perceive NASA as the gold star. I can think of no stronger statement relative to NASA's confidence both in Bigelow Aerospace and expandable habitat technology than their desire to place BEAM aboard the ISS," Gold said. "That speaks volumes not just domestically, but possibly more importantly, overseas as well. I think that any sovereign client or potential clientele should be paying attention to this.”
Gold said the private entrepreneurial firm is pleased to be working with NASA to further validate the promise and benefits of expandable habitat technology – and not only in low-Earth orbit, but beyond.
Beyond BEAM, Bigelow Aerospace is "moving aggressively" on the larger BA 330 module, "dedicating a great deal of resources" to expeditiously push forward an expandable habitat of that size.
Beyond LEO habitats
According to the Bigelow Aerospace website, the BA 330 can function as an independent space station, and several BA 330 habitats can be connected together in a modular fashion to create an even larger and more capable orbital space complex.
Robert Bigelow and his team have extensively blueprinted concepts for their expandable habitats to be used at other destinations.
"Expandable habitats are an enabling technology that will make the dream of robust beyond-LEO human space exploration a reality," Gold said. "Regardless of the ultimate destination, be it L2 [Lagrange Point 2], the surface of the moon or even a historic mission to Mars, the large volumes provided by Bigelow Aerospace systems, combined with enhanced protection from radiation and physical debris, make habitats such as the BA 330 an essential part of any realistic beyond-LEO architecture."
Gold said he knows Capitol Hill wants to see a robust beyond-LEO human space exploration strategy, but that new funding will be hard to come by.
“The BA 330 and expandable habitats will not just offer enhanced protection from radiation and micrometeorites, but protect future astronauts from a much more dangerous threat …lack of funding," Gold concluded.

Source of Article : space.com

2013년 1월 15일 화요일

Inflatable Private Space Stations: Bigelow's Big Dream

NASA's decision to buy an inflatable new room for the International Space Station may push the module's builder —commercial spaceflight company Bigelow Aerospace — one step closer to establishing its own private stations in orbit.
Last week, NASA announced that it will pay $17.8 million for the Nevada-based company's Bigelow Expandable Activity Module (BEAM), which will be affixed to the huge orbiting lab as a technology demonstration.
NASA and Bigelow will discuss the deal during a media event Wednesday (Jan. 16) in North Las Vegas, where the company is headquartered. BEAM could help prove out the viability of inflatable crew habitats, potentially jump-starting Bigelow's ambitious plans in low-Earth orbit and, perhaps, on the surface of the moon.

Expanding access to space
Bigelow Aerospace was founded in 1999 by Robert Bigelow, who made his fortune in real estate and finance. He also owns the Budget Suites of America hotel chain, for example.
Bigelow Aerospace specializes in expandable habitats, which launch in a compact form and then inflate upon reaching space. The company says expandable modules offer greater on-orbit volume and better protection against radiation and micrometeoroid strikes than traditional "tin can" designs can provide.
Inflatable modules were first pursued seriously by NASA, which developed a design called TransHab (short for "Transit Habitat") for possible use on the International Space Station. When Congress cancelled the TransHab program in 2000, Bigelow officials licensed the patents and began adapting the technology for the company's own purposes.
The company's goals are big: to establish private space stations that could be used by many different clients for a variety of purposes, from research to tourism.
"We are primarily focused on providing sovereign clients (individual or groups of nations) and companies with the opportunity to lease space and resources aboard our habitats for a broad array of activities, ranging from turn-key astronautics to conducting ground-breaking and lucrative biotech research," Bigelow Aerospace's website states.
"We offer a way for countries to bolster their human spaceflight programs while at the same time reducing their budgets, or for smaller countries that thought human spaceflight was beyond their financial reach to enjoy capabilities that until now only the wealthiest nations have been able to sponsor."

Making it happen
Bigelow has already put hardware into space, launching the prototype modules Genesis 1 and Genesis 2 to orbit in 2006 and 2007, respectively.
Both Genesis habitats are 14.4 feet long by 8.3 feet wide (4.4 by 2.5 meters), with about 406 cubic feet (11.5 cubic m) of pressurized volume. The BEAM module that will be attached to the International Space Station in two years or so will likely be of similar size.
But Bigelow is developing a much larger module, called the BA-330 because it offers 330 cubic meters of usable internal volume. The company envisions linking up two or more BA-330s in orbit to create its first space stations, which have already attracted attention from potential clients.
For example, Bigelow has signed memoranda of understanding with seven governments that wish to use the company's orbiting facilities — Australia, Singapore, the United Kingdom, the Netherlands, Japan, Sweden and Dubai, in the United Arab Emirates.
Bigelow will offer a variety of rental packages to its clients when the stations are up and running, perhaps starting with $28.75 million for an all-inclusive 30-day stay for one astronaut (the company has quoted this figure in the past).
Clients may have several different ways to reach Bigelow's habitats. The company has set up a partnership with the California-based firm SpaceX to use its Dragon spacecraft, and another with Boeing for use of its CST-100 capsule.
Bigelow's dreams don't stop in low-Earth orbit. Robert Bigelow has voiced an interest in setting up outposts on the moon, which would employ BA-330 habitats that are joined together in space, flown down to the lunar surface and then covered with moon dirt to protect against radiation, temperature extremes and micrometeorite impacts.
As such ambitious goals demonstrate, Bigelow seeks to fundamentally transform the way humanity uses space, opening up the final frontier to greater exploration and exploitation.
"Mr. Bigelow created Bigelow Aerospace with the express purpose of revolutionizing space commerce via the development of affordable, reliable and robust expandable space habitats," the company's website states.

Source of Article : space.com

'Garden Sprinkler' Star Fires Jet at Near Light Speed

A NASA space telescope has captured a movie of a collapsed star that's spinning more than 11 times each second and unleashing ultra-fast particles that move at 70 percent of the speed of light.
The new video of the spinning Vela pulsar was recorded by the Chandra X-ray Observatory shows a new look at the ultra-dense star, which is just 12 miles (19 kilometers) wide and located about 1,000 light-years from Earth. It spews out a jet of charged particles along its rotation axis as it spins.
"We think the Vela pulsar is like a rotating garden sprinkler — except with the water blasting out at over half the speed of light," researcher Martin Durant, of the University of Toronto in Canada, said in a statement.
Pulsars get their name because they appear to pulse on and off as beams of light sweep across Earth and then away. The Vela pulsar is a compact neutron star, a star that has collapsed so much that it is composed only of neutrons.
The Vela pulsar's jets look strikingly like a rotating helix and appear similar to those produced by accreting supermassive black holes in other galaxies. But since the pulsar's jet is smaller, more quickly changing and closer to Earth by comparison, it can be studied in much great detail than jets from black holes.
The pulsar's jets are also long, stretching out across about 0.7 light-years. One light-year is the distance light travels in a single year, about 6 trillion miles (10 trillion km).

The new observations from the Chandra observatory (which were obtained between June and September 2010) suggest the Vela pulsar may be slowly wobbling as it whirls around, Chandra scientists said. It is possible that the neutron star is no longer a perfect sphere, causing the wobble, they added. Such wobbling by a star is known as its precession, and researchers said it could be caused when the Vela pulsar's fast spin is compounded by intermittent boosts of increased speed.
"The deviation from a perfect sphere may only be equivalent to about one part in 100 million," said George Washington University researcher Oleg Kargaltsev. " Neutron stars are so dense that even a tiny distortion like this would have a big effect."
If the distorted shape theory is confirmed, the Vela pulsar would be the first neutron star ever seen with such a feature, researchers said. Another idea suggests that the magnetic field of the Vela pulsar, not its shape, may be the true culprit behind the strange shape of the super-fast jets.
The research was presented last week at the American Astronomical Society meeting in Long Beach, Calif., and detailed in The Astrophysical Journal.
The new Vela pulsar study marked the second time astronomers have created a movie of the object's strange jets using the Chandra observatory. A similar movie was recorded in 2003, but was based on shorter observations that did not reveal the pulsar's odd precession motion, researchers said.

Source of Article : space.com

Hubble Telescope to Snap 6 New 'Deep Field' Views of Universe

The Hubble Space Telescope's iconic "Deep Field" photo wowed the world in 1996 by revealing a huge collection of galaxies hiding inside a patch of the sky that looked like nothing more than blank space. Now NASA plans to image six more "empty" bits of sky for a whole new set of deep fields that could revolutionize astronomy once again.
Hubble captured the Deep Field by staring at the same point over many hours, letting particles of light from extremely distant objects slowly pile up to reveal celestial bodies that would otherwise be too faint to see.
Since the original photo's release, Hubble looked even longer at the same spot to create the "Ultra Deep Field" in 2004 and then the "eXtreme Deep Field" in 2012. But the new effort, called Hubble Frontier Fields, will be the first to try a similar technique on some new areas of the heavens. These photos won't go quite as deep as the Ultra Deep Field, but will represent some of the deepest images of the universe ever taken.
"As iconic as the Ultra Deep Field is, now we'll have six that are almost as nice," said Hubble scientist Dan Coe of the Space Telescope Science Institute in Baltimore, Md., which manages the telescope.
The Hubble Frontier Fields will collect light for about 45 hours each, spread over a period of three years, imaging objects that existed in the first 500 million years after the Big Bang.
Plus, in a new twist, astronomers will image each of the six blank patches of sky in combination with nearby galaxy clusters, whose gravity can act as a cosmic magnifying lens to zoom in on small, distant objects behind them.

Researchers will "observe six galaxy clusters and blank fields in parallel," Coe told. "While they're observing a cluster, the other camera is just far enough away where it's not really looking at the cluster anymore. It'll be essentially blank. To really go deep in both of these at the same time, that's never been done before."
The added magnification boost of the clusters' gravity should make these pictures the deepest glimpses of the universe yet. The shots could capture galaxies that are older and farther away than anything ever seen before.
"Some of them will be among the most distant galaxies yet found," said Coe, who led the study of one of the current contenders for farthest galaxy ever seen, MACS0647-JD, which lies about 13.3 billion light-years away.
The original Deep Field photo revealed about 3,000 previously unknown galaxies in a patch of sky only 2.5 arc-minutes across, or about one 24-millionth of the whole sky.
The new fields will determine whether that huge haul was a fluke, or if almost any patch of blank sky contains a similar wealth of treasures."You don't know, it might be a special part of the sky you're looking at," Coe said.
Hubble will begin observing the first of the new fields later this year.
The nearly23-year-old telescope is still going strong after five upgrades from visiting space shuttle crews. NASA hopes to keep the observatory running until at least 2018, when its successor, the James Webb Space Telescope, is due to launch.

Source of Article : space.com

Warp Speed: What Hyperspace Would Really Look Like

The science fiction vision of stars flashing by as streaks when spaceships travel faster than light isn't what the scene would actually look like, a team of physics students says.
Instead, the view out the windows of a vehicle traveling through hyperspace would be more like a centralized bright glow, calculations show.
The finding contradicts the familiar images of stretched out starlight streaking past the windows of the Millennium Falcon in "Star Wars" and the Starship Enterprise in "Star Trek." In those films and television series, as spaceships engage warp drive or hyperdrive and approach the speed of light, stars morph from points of light to long streaks that stretch out past the ship.
But passengers on the Millennium Falcon or the Enterprise actually wouldn't be able to see stars at all when traveling that fast, found a group of physics Masters students at England's University of Leicester. Rather, a phenomenon called the Doppler Effect, which affects the wavelength of radiation from moving sources, would cause stars' light to shift out of the visible spectrum and into the X-ray range, where human eyes wouldn't be able to see it, the students found.
"The resultant effects we worked out were based on Einstein's theory of Special Relativity, so while we may not be used to them in our daily lives, Han Solo and his crew should certainly understand its implications," Leicester student Joshua Argyle said in a statement.
The Doppler Effect is the reason why an ambulance's siren sounds higher pitched when it's coming at you compared to when it's moving away — the sound's frequency becomes higher, making its wavelength shorter, and changing its pitch.
The same thing would happen to the light of stars when a spaceship began to move toward them at significant speed. And other light, such as the pervasive glow of the universe called the cosmic microwave background radiation, which is left over from the Big Bang, would be shifted out of the microwave range and into the visible spectrum, the students found.
"If the Millennium Falcon existed and really could travel that fast, sunglasses would certainly be advisable," said research team member Riley Connors. "On top of this, the ship would need something to protect the crew from harmful X-ray radiation."

The increased X-ray radiation from shifted starlight would even push back on a spaceship traveling in hyperdrive, the team found, slowing down the vehicle with a pressure similar to the force felt at the bottom of the Pacific Ocean. In fact, such a spacecraft would need to carry extra energy reserves to counter this pressure and press ahead.
Whether the scientific reality of these effects will be taken into consideration on future Star Wars films is still an open question.
"Perhaps Disney should take the physical implications of such high speed travel into account in their forthcoming films," said team member Katie Dexter.
Connors, Dexter, Argyle, and fourth team member Cameron Scoular published their findings in this year's issue of the University of Leicester's Journal of Physics Special Topics.

Source of Article : space.com

Curiosity Rover to Drill Mars Rock Once Soaked by Water

NASA's Mars rover Curiosity is preparing to drill into a Red Planet rock for the first time and delve deeper into a site that was exposed to liquid water long ago, scientists announced today (Jan. 15).
Over the next two weeks, the 1-ton Curiosity rover will drill a rock in an outcrop that scientists have christened "John Klein." Evidence is strong that water flowed and percolated through the area in the distant past, researchers said.
"Basically, these rocks were saturated with water," Curiosity chief scientist John Grotzinger, of Caltech in Pasadena, told reporters during a teleconference.

Breaking out the drill
Curiosity landed inside Mars' huge Gale Crater on Aug. 5, kicking off a surface mission to determine if the area has ever been capable of supporting microbial life.
The $2.5 billion rover has spent much of its first five months on the Red Planet testing out its 10 science instruments and other gear, making sure everything is in good working order. The drill — which will allow Curiosity to bore 1 inch (2.5 centimeters) into Martian rock, deeper than any robot has gone before — is the last major tool to check out.
The mission team wanted to find a suitably intriguing site for the first drilling operation, and they say John Klein fits the bill. The outcrop, which was named after a former Curiosity deputy project manager who died in 2011, is part of a geologically diverse site with many water-related features.
For example, the area is shot through with light-colored mineral veins similar to the one spotted by Curiosity's smaller cousin Opportunity a year or so ago in another part of the Red Planet.
"On Earth, forming veins like these requires water circulating in fractures," Nicolas Mangold of the University of Nantes in France, a team member for Curiosity's ChemCam instrument, said in a statement.
Further, a nearby outcrop called Shaler harbors evidence of sediment transport. Some of Shaler's grains are too big to have been moved by wind, suggesting that liquid water pushed them along, researchers said. That's not terribly surprising, as Curiosity has already rolled through a streambed that once flowed with ankle-deep water in the ancient past.
The geological diversity of the John Klein area, and its potential to shed light on Mars' wetter and warmer past, have mission scientists excited.
"This is, I would guess, at least as complex a history for the involvement of water that we've seen anywhere on Mars so far," Grotzinger said. "The main goal of this [drilling operation] is to try to assess this material in a very general way that will give us an appraisal of the habitability of this environment."

Taking it slowly
Curiosity is just a few meters away from the John Klein outcrop at the moment. In the coming days, the rover team will select a particular section of the outcrop for drilling, and the first hole should be bored within two weeks or so, researchers said.
"It's really the most difficult aspect of the surface mission," said Curiosity project manager Richard Cook, of NASA's Jet Propulsion Laboratory in Pasadena. "We're undoubtedly going to learn a lot about how to drill things on Mars, as it's the first time we've ever done that. And so we will probably go slowly."
Mission scientists have waited more than five months to try out the rover's drill on Mars, and they're eager to see what the tool can do.
"We're thrilled, and we can't wait to get drilling on this stuff," Grotzinger said.

    Source of Article : space.com

    2013년 1월 14일 월요일

    NASA's Donated Spy Telescopes May Aid Dark Energy Search

    Astronomers are excited by the possibility of using one of two cast-off spy satellite telescopes gifted to NASA to probe for dark energy.
    They have already come up with a design that would incorporate the spy telescope into the proposed Wide Field Infrared Survey Telescope (WFIRST), a high-priority NASA mission that would hunt for dark energy, exoplanets and supernovae.
    Though a final review and economic analysis won't be released until April, the new design based on the donated scopes would boost WFIRST's abilities significantly, some researchers say. But the concept could also require more power and a bigger launch vehicle, potentially raising the project's roughly $1.5 billion price tag.

    More powerful probe
    In June, the U.S. National Reconnaissance Office donated to NASA two 2.4-meter telescopes that were part of a failed spy satellite program. The telescopes have roughly twice the collecting surface as earlier designs of WFIRST, which allows for better resolving power. They also have a better field of view than existing telescopes (though smaller than some initial design proposals).
    "The magic of this telescope compared to existing telescopes like the James Webb Telescope or the Hubble Telescope is it has a huge field of view," NASA astrophysicist Neil Gehrels said during a presentation of the new designs here at the 221st meeting of the American Astronomical Society on Jan. 8.
    The new proposed design also includes a coronagraph, which can block out starlight to resolve exoplanets and other objects.
    Complementary telescope
    Another advantage of using the spy telescope is that it may complement existing projects.
    For instance, the Euclid project headed by the European Space Agency will scan for dark energy — the mysterious force thought to be accelerating the expansion of the universe — but using a wider, shallower survey. The proposed WFIRST design could then go in and probe in more detail, researchers said.
    In addition, because the new telescope would have a field of view 100 times wider than that of the Hubble Space Telescope, it could provide accurate counts of galaxy clusters, which is important for dark energy studies, said David Spergel, an astrophysicist at Princeton University who is part of the new proposed design review team.
    The new design would also provide a better ability to search for the bending of light by gravity, improving the ability to find and characterize exoplanets. The proposed coronagraph could help the instrument find small, rocky worlds, researchers said.
    And the new telescope could detect thousands of new supernovae, or exploded stars.
     "For supernova science, it really represents a major step forward," Spergel said.
    Better, faster, cheaper?
    Though the cost analysis won't be completed until April, several factors could make a souped-up WFIRST as pricey as building the original designs from scratch — or perhaps even more expensive,
    Because the gifted scope has a larger mirror, it will run hotter — currently, at 59 degrees Fahrenheit (15 degrees Celsius). To improve its ability to operate deeper into the infrared spectrum, the design team is hoping to cool it to minus 10 degrees Fahrenheit (minus 23 degrees Celsius).
    The big telescope might also require a bigger launch vehicle — possibly one that doesn’t yet exist.
    "It may not be cheaper; it may well be more expensive," Spergel said.
    While several astronomers argued the new design would probably be cheaper, simply because the major element — the telescope — is already in place, others were not convinced.
    Ned Wright, an astrophysicist at UCLA who spoke during the meeting, expressed extreme skepticism about the NRO's cast-off spy telescopes, saying the new design was likely to be plagued by cost overruns.
    "Would anybody like to wager a case of Jameson on the question of whether this could be built by 2024 for less than $1.5 billion?" he asked.

    Source of Article : space.com

    Milky Way Galaxy May Be Less Massive Than Thought

    The Milky Way galaxy, home of Earth's solar system, may actually be only half as massive as currently thought, scientists say.
    Stars in the far outer reaches of the Milky Way, between 260,000 and 490,000 light-years from the galactic center, are cruising around surprisingly slowly, researchers found. Galactic mass and star velocities are linked, so the results could have big implications.
    "Because these velocities are so low, the mass of our galaxy may be much lower than we once thought," lead author Alis Deason, of the University of California, Santa Cruz, told reporters Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Socity in Long Beach, Calif.
    "If we infer the properties of the stars that we think are reasonable, then we find the mass of the Milky Way could be half as massive as we currently believe," added Deason, who performed the research while at the University of Cambridge in England.

    The Milky Way is composed of three main parts: a central bulge, a relatively flat disk and a roughly spherical surrounding halo.
    Deason and her team looked far out into the Milky Way's halo, which extends far beyond the 100,000-light-year-wide disk. They measured the radial velocities of a sample of distant halo stars using two different instruments: the European Southern Observatory's 8.2-meter telescope in Chile and the 4.2-meter William Herschel Observatory in Spain.
    They found that the dispersion, or spread, of halo-star velocities was about half that seen for stars closer to the galactic center.
    "This was quite a surprise when we found this," Deason said.
    Using this information, the team calculated that the total mass of the Milky Way out to such extreme distances may be between 500 billion and 1 trillion times that of our sun — substantially lower than the current leading estimate, Deason said.
    But the new study is not necessarily the final word on the Milky Way's mass, which is not well understood.
    "The problem is, we are really in unknown territory," Deason said. "We are assuming properties of these stars that are the same in the inner parts of the galaxy. And this is something that really needs to be verified, what we're assuming, in terms of their density profile and also what their orbits are like."
    Future work along these lines could help astronomers map the distribution of mass throughout the Milky Way, Deason said, potentially shedding light on the mysterious dark matter that is thought to make up more than 80 percent of all matter in the universe.
    "I think we will be able to use measurements like this to not only say what the total mass is, but also if the dark matter distribution is what we expect," she said. "At the moment, we just don't know."

    Source of Article : space.com

    NASA Unveils Last Moon Video by Doomed Spacecraft

    A NASA probe recorded a spectacular flyover video of the moon's far side shortly before intentionally slamming into a lunar mountain last month.
    NASA's Ebb spacecraft shot the stunning final moon video on Dec. 14, just three days before it and its twin Flow ended their gravity-mapping mission, known as Grail, with a dramatic crash near the moon's north pole.
    Ebb was just 6 miles (10 kilometers) above the lunar surface when it captured the images using its MoonKAM (Moon Knowledge Acquired by Middle school students) camera. The probe was skimming over the far side's northern hemisphere at the time, near an impact crater named Jackson.

    Grail scientists pieced together about 2,400 individual frames to make the nearly two-minute video, NASA officials said.
    The $496 million Grail mission — short for Gravity Recovery and Interior Laboratory — launched in September 2011, and Ebb and Flow arrived in lunar orbit about three months later. The washing-machine-size spacecraft spent a year zipping around the moon, detecting the tiny changes in the distance between them caused by lunar mountains, craters and subsurface mass concentrations.
    The Grail team used these super-precise measurements to construct an incredibly accurate map of the lunar gravity field — the best ever created for any celestial body, researchers said.
    But Ebb and Flow couldn't keep flying forever. They were running out of fuel by last month and would have crashed into the moon eventually, so the mission team decided to bring them down in a controlled fashion, far from the Apollo landing sites and other areas of historical importance.
    So on Dec. 17, the two probes slammed into a crater rim near the moon's north pole. Shortly after the impact, NASA announced that the crash site would be named after the late Sally Ride, America's first woman in space.
    Ride had led Grail's MoonKAM project, which allowed schoolkids around the world to pick out sites for Ebb and Flow to photograph. She died last July at the age of 61 after a battle with pancreatic cancer.

    Source of Article : space.com