SpaceJibe

January 26, 2011

Astronomers Discover Oldest Ever Galaxy

Filed under: Big Bang, Black Holes, Cool, Cosmology, Space Exploration — bferrari @ 9:23 pm
This is the image of the sky in the region of the Hubble Ultra-Deep field taken with the new Wide Field Camera 3 Infra-red imager (WFC3/IR) and is the deepest image of the sky ever obtained in the near-infrared

This is the image of the sky in the region of the Hubble Ultra-Deep field taken with the new Wide Field Camera 3 Infra-red imager (WFC3/IR) and is the deepest image of the sky ever obtained in the near-infrared

Astronomers using the Hubble Space Telescope have peered further back in time than ever before, spotting a galaxy that formed less than 500 million years after the birth of our universe, making it the oldest and most distant ever seen.

The find, reported today (Jan. 26) in the journal Nature, should help astronomers better understand the early days of the universe, researchers said. In particular, the discovery should shed light on the evolution of early galaxies, which first formed just a few hundred million years after the Big Bang.

“In essence, the most important aspect of this is, it provides us with some sense of how fast galaxies are building up,” lead author Rychard Bouwens, of the University of California, Santa Cruz (UCSC) and Leiden University in The Netherlands, told SPACE.com. “It provides a sort of measuring stick.”

Peering backward through time

Bouwens and his colleagues analyzed observations made by NASA’s Hubble Space Telescope. They looked at infrared data gathered by Hubble’s Wide Field Camera 3, which was installed on the telescope in 2009. [Most Amazing Hubble Discoveries]

The researchers found evidence of a galaxy with a redshift of 10.3. “Redshift” is a measure of how much the expansion of space has stretched an object’s light to longer (or redder) wavelengths. Light from objects moving away from us shifts to the red end of the spectrum as its wavelengths are stretched. The shift, known as the Doppler phenomenon, is experienced on Earth when sound waves from an ambulance change pitch when the ambulance moves toward you versus away from you.

Astronomers use redshift measurements to determine an object’s distance, and by extension its age. The bigger the redshift, the greater the distance.

A redshift of 10.3 corresponds to a distance of about 13.2 billion light-years. That is, it’s taken 13.2 billion years for the light from the newly discovered galaxy — which has been named UDFj-39546284 — to reach us.

That makes UDFj-39546284 the most distant known galaxy in the universe, beating out the old record-holder by about 100 million light-years.

Since the universe is roughly 13.7 billion years old, UDFj-39546284 was around nearly at the beginning — just 480 million years after the Big Bang, or when the universe was just 4 percent of its current age.

Officially, UDFj-39546284 remains a “galaxy candidate,” requiring some more observations to confirm its existence and age with certainty. But after performing a number of tests, Bouwens and his team are confident that the galaxy is there, and that its redshift is around 10.3.

“Everything we found was completely consistent with it being a real source,” Bouwens said. “It looks really good right now.”

Understanding galaxy formation

In addition to studying UDFj-39546284, the researchers also looked at several galaxies that are slightly younger, dating to about 650 million years after the Big Bang. They saw dramatic differences between the older and younger galaxies, suggesting that the rate of star birth jumped by a factor of 10 in the intervening 170 million years.

“This is an astonishing increase in such a short period, just 1 percent of the current age of the universe,” co-author Garth Illingworth, of UCSC, said in a statement.

The team also found big differences in the number of galaxies observed in the two epochs. They discovered just the one galaxy dating to 480 million years after the Big Bang, while previous searches found nearly 50 galaxies just 170 million years later.

The new observations could help astronomers better understand how the universe’s first galaxies coalesced and grew, researchers said.

“We definitely see strong evidence for hierarchical buildup,” Bouwens said. “It’s quite striking.”

Reionizing the universe

The new study also bears on an age-old question in astronomy. At about 300,000 years after the Big Bang, the hydrogen in the universe was neutral, meaning it carried no charge. By 1 billion years later, however, something had thrown off enough radiation to ionize most of this hydrogen, splitting it into its constituent electrons and protons.

“The results from this study imply that the stars and galaxies that they can detect would only provide about 12 percent of the radiation that you would need,” Rachel Somerville of the Space Telescope Science Institute, who was not involved in the current study, told reporters today (Jan. 26). “So this is quite a mystery that needs to be solved.”

The new results hint that early galaxies such as UDFj-39546284 may have played a role in this reionization of the universe. But their contributions alone were perhaps not great enough to do the job, suggesting that some mystery source is also partly responsible, researchers said.

The team’s observations in this regard are not definitive. To get to the bottom of the reionization mystery, astronomers will need to gather more data, according to Bouwens.

“At redshift 10, we made a relatively conservative assumption about how many of these faint galaxies there were,” Bouwens said. “If there actually turn out to be more, they could be more important.”

Looking to the future

While the new study takes an unprecedented look into the past, new instruments will likely be required to go back even farther, to the first epochs of galaxy formation, researchers said.

One of the most promising future instruments is NASA’s James Webb Space Telescope (JWST), Bouwens said. The powerful successor to Hubble, JWST has long been hampered by cost overruns and delays.

Previously slated for launch in June 2014, JWST will be able to lift off no earlier than September 2015, according to an independent review panel convened last year to assess the telescope’s problems.

Whenever it’s finally cleared to take to the skies, JWST will have a huge impact, according to Bouwens.

“We’re now just able to scratch the surface of what will be possible,” he said. “We should be able to push out to redshift 12 or 13, and maybe further. It’s unclear what we’ll be able to do.”

*   Countdown: The Most Amazing Hubble Discoveries
*   The Big Bang: Solid Theory, But Mysteries Remain
*   Image Gallery: The Hubble Space Telescope: 20 Years of Cosmic Awe

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January 20, 2011

Breakthrough Raygun Could Revolutionize Navy’s Weaponry

Filed under: Cool, Gadgets, Government Policies, Military — bferrari @ 4:07 pm

The battleships of the future will be equipped with mega-watt free electron lasers

The battleships of the future will be equipped with mega-watt free electron lasers

The Navy has passed a major milestone in its quest to build an incredibly powerful new anti-air raygun.

Scientists with the Navy’s Office of Naval Research have demonstrated a prototype system capable of producing from thin air the electrons needed to generate ultrapowerful, “megawatt-class” laser beams for the agency’s next-generation system.

“The injector performed as we predicted all along,” said Dinh Nguyen, senior project leader for the Free Electron Laser (FEL) program at the Los Alamos National Lab, N.M. “But until now, we didn’t have the evidence to support our models. We were so happy to see our design, fabrication and testing efforts finally come to fruition.”

He said the group is hoping to set a world record with the futuristic new weapon — which could be the Holy Grail of military lasers.

FEL technology generates powerful laser beams by passing a stream of electrons — those tiny, charged particles of matter — through magnetic fields. Using electrons means avoiding the hassle of chemical fuels that are required for ordinary gas lasers, and bypassing the heating issue of electronic lasers.

FEL lasers can also be calibrated more specifically for anti-aircraft purposes, the Navy said, to adjust for precipitation, cloud cover, or humidity.

Quentin Saulter, FEL program manager for the Navy’s research arm, said the implications of the FEL’s progress are monumental. “This is a major leap forward for the program and for FEL technology throughout the Navy,” Saulter said. “The fact that the team is nine months ahead of schedule provides us plenty of time to reach our goals by the end of 2011.”

The research team hopes to have a full-power prototype by 2018, which would have the ability to instantly blast targets in the sky.

Navy ships have become vulnerable in modern times to supersonic missiles because of their slower defense systems, the agency worries. “The FEL is expected to provide future U.S. Naval forces with a near-instantaneous laser ship defense in any maritime environment throughout the world,” Saulter said.

Moreover, because future ships may very well use a form of electronic propulsion, there would be a readily available supply of electrons to power the raygun.

Originally invented by John Madey in 1976 at Stanford University, the project was picked up and pursued by the ONR in the 1980s — and may finally become a reality

Source

New Reactor Harnesses Sun’s Energy Like Plants

Filed under: Gadgets, Global Warming — bferrari @ 3:53 pm
In the reactor, sunlight heats a ceria cylinder which breaks down water or carbon dioxide, just like plants do (CALTECH)

In the reactor, sunlight heats a ceria cylinder which breaks down water or carbon dioxide, just like plants do (CALTECH)

Researchers have unveiled a prototype reactor which mimics plant life, turning the Sun’s energy to make hydrocarbon fuel.

Developed by a team of scientists from the United States and Switzerland, The solar device uses the Sun’s rays and the metal ceria, or cerium oxide, to break down water or carbon dioxide into energy which can be stored and transported.

Harnessing the power of the sun has been but a pipe dream as conventional solar panels must use the power they generate in situ. With the ceria fueled reactor, this issue is solved.

The scientists, which include Caltech professor Sossina M. Haile and Swiss Institute of Energy Technology professor Aldo Steinfeld, wanted to figure out a way to harness the sun efficiently, without incredibly rare materials. They decided on ceria, a relatively abundant “rare-earth” metal with very special properties.

The reactor takes advantage of ceria’s ability to “exhale” oxygen from its crystalline framework at very high temperatures and then “inhale” oxygen back in at lower temperatures.

“What is special about the material is that it doesn’t release all of the oxygen. That helps to leave the framework of the material intact as oxygen leaves,” Haile explains. “When we cool it back down, the material’s thermodynamically preferred state is to pull oxygen back into the structure.”

Conceptually, the device has boundless potential with its ability to break down water into hydrogen fuel and oxygen or carbon dioxide into carbon monoxide and oxygen, key ingredients for the fuel cell component methanol. Because they are broken down thermochemically, the resulting fuel is easy to transport.

But the prototype is still in its infant stages and extremely inefficient, harnessing only 0.7% to 0.8% of the solar energy it absorbs with most lost through heat or re-radiation. The researchers are confident they can reach levels of around 20% which would make the device commercially viable.

Source

January 17, 2011

NASA Shows Off Planes of the Future

Filed under: Cool, Gadgets, Government Policies, Military, Space Exploration, Space Ships — bferrari @ 3:53 pm

NASA is looking into advanced aircraft that could enter service within the next 25 years — designs that range from the familiar to the very far out.

Other revolutionary technologies help achieve range, payload and environmental goals

Other revolutionary technologies help achieve range, payload and environmental goals

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January 12, 2011

Thunderstorms Proven to Create Antimatter, NASA Finds

Filed under: Cool, Earth, Inner Solar System — bferrari @ 9:18 am
NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms (NASA)

NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms (NASA)

Thunderstorms create far more than just rain. NASA has accidentally discovered that they spit out antimatter, too.

Scientists using the space agency’s Fermi Gamma-ray Space Telescope have detected beams of antimatter produced above thunderstorms on Earth, a phenomenon never seen before. They believe the antimatter particles were formed during “terrestrial gamma-ray flashes,” sharp bursts produced daily inside thunderstorms that are still poorly understood.

Thunderstorms are known to create supercharged electric fields, of course, as evidenced by lightning. But the creation of antimatter is something else.

“These signals are the first direct evidence that thunderstorms make antimatter particle beams,” said Michael Briggs, a member of Fermi’s Gamma-ray Burst Monitor team at the University of Alabama in Huntsville.

Scientists long have suspected that these terrestrial gamma-ray flashes (TGFs) arise from the strong electric fields near the tops of thunderstorms. Under the right conditions, they say, the field becomes strong enough that it drives an upward avalanche of electrons. Reaching speeds nearly as fast as light, the high-energy electrons give off gamma rays when they’re deflected by air molecules.

Normally, these gamma rays are detected as a TGF. But the cascading electrons produce so many gamma rays that they blast electrons and positrons clear out of the atmosphere. This happens when the gamma-ray energy transforms into a pair of particles: an electron and a positron. It’s these particles that reach Fermi’s orbit in space.

Fermi is designed to monitor gamma rays, the highest energy form of light. When antimatter striking Fermi collides with a particle of normal matter, both particles immediately are annihilated and transformed into gamma rays. Now Fermi has detected gamma rays with energies of over half a million electron volts, a signal indicating an electron has met its antimatter counterpart, a positron.

“In orbit for less than three years, the Fermi mission has proven to be an amazing tool to probe the universe. Now we learn that it can discover mysteries much, much closer to home,” said Ilana Harrus, Fermi program scientist at NASA headquarters in Washington.

“The Fermi results put us a step closer to understanding how TGFs work,” said Steven Cummer at Duke University. “We still have to figure out what is special about these storms and the precise role lightning plays in the process.”

Source

January 10, 2011

NASA Discovers Smallest Alien Planet Yet

Filed under: Cool, Exoplanets, Extraterrestrial Life, Space Exploration — bferrari @ 11:44 pm
Artist's concept of Kepler-10b. NASA

Artist's concept of Kepler-10b. NASA

SEATTLE – NASA has discovered the smallest planet ever seen beyond our solar system – a rocky world just 1.4 times larger than Earth – using its planet-hunting Kepler observatory.

The planet, called Kepler-10b, is also the first rocky alien planet to be confirmed by NASA’s Kepler mission using data collected between May 2009 and early January 2010. But, while Kepler-10b is a rocky world, it is not located in the so-called habitable zone – a region in a planetary system where liquid water can potentially exist on the planet’s surface.

“Kepler-10b is the smallest exoplanet discovered to date, and the first unquestionably rocky planet orbiting a star outside our solar system,” said Natalie Batalha, Kepler’s deputy science team leader at NASA’s Ames Research Center in Moffett Field, Calif., at a press conference here at the 217th American Astronomy Society meeting.

“It’s an important milestone for our team, and I think it’s an important milestone for humanity,” said Batalha, who also led the study that discovered the newfound world. The research will appear in an upcoming issue of The Astrophysical Journal.

Kepler-10b is the latest in the growing legion of extrasolar planets scientists are discovering around alien stars. To date, more than 500 exoplanets have been confirmed.

Small, rocky world

Kepler-10b orbits its parent star once every 0.84 days, which means it is more than 20 times closer to its star than Mercury is to our sun, which places it outside the parameters of the habitable zone.

Kepler-10 is located about 560 light-years away and is approximately the same size as our sun. The star’s age is estimated to be 8 billion years old.

The exoplanet’s star, Kepler-10, was the first one identified as capable of harboring a small transiting planet, placing the star at the top of the list for ground-based observations using the W.M. Keck Observatory 10-meter telescope in Hawaii.

Scientists waiting for a signal to confirm Kepler-10b as a planet were not disappointed. Keck was able to measure tiny changes in the star’s spectrum, called Doppler shifts, caused by the telltale tug exerted by the orbiting planet.

“The discovery of Kepler-10b is a significant milestone in the search for planets similar to our own,” said Douglas Hudgins, Kepler program scientist at NASA headquarters in Washington, D.C. “Although this planet is not in the habitable zone, the exciting find showcases the kinds of discoveries made possible by the mission and the promise of many more to come.”

Understanding the planet Kepler-10b

Knowledge of the planet is only as good as the knowledge of the star it orbits.

Since Kepler-10 is one of the brighter stars being targeted by Kepler, scientists were able to detect high-frequency variations in the star’s brightness generated by stellar oscillations, or starquakes. This analysis allowed scientists to pin down Kepler-10b’s properties.

The researchers picked up on a clear signal in the data arising from light waves that travel within the interior of the star. Kepler Asteroseismic Science Consortium scientists use the information to better understand the star, just as earthquakes are used to learn about Earth’s interior structure. As a result of this analysis, Kepler-10 is one of the most well-characterized planet-hosting stars in the universe.

And this is good news for the team studying Kepler-10b. Accurate stellar properties yield accurate planet properties. In the case of Kepler-10b, the picture that emerges is of a rocky planet 1.4 times the size of Earth, with a mass that is 4.6 times that of Earth, and an average density about as dense as an iron dumbbell.

“It looks to be overdense, in the same way Mercury is overdense,” Batalha said.

The surface gravity of Kepler-10b is also thought to be more than twice that of Earth, Batalha said. So, it is unlikely that the exoplanet has big mountains. Instead, there may be canyons carved by molten rock.

The Kepler observatory stares at more than 156,000 stars in a star field located in the constellations Cygnus and Lyra. Kepler is the first NASA mission capable of detecting Earth-size planets in or near the habitable zone. The spacecraft’s ultra-precise photometer measures the tiny decrease in a star’s brightness that occurs when a planet crosses in front of it.

The size of the planet can then be derived from these periodic dips in brightness. The distance between the planet and the star can also be calculated by measuring the time between successive dips as the planet orbits the star.

“This planet, Kepler-10b, will go into every textbook in astronomy, worldwide,” said Geoff Marcy, a professor of astronomy at the University of California, Berkeley. “I think it is clearly a historic discovery.”

Follow SPACE.com Senior Writer Mike Wall @michaeldwall for the latest from the 217th AAS American Astronomy Society meeting. SPACE.com Staff Writer Denise Chow contributed to this report from New York City.

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January 7, 2011

Life’s Building Blocks May Have Been Found on Mars

Filed under: Cool, Extraterrestrial Life, Inner Solar System, Life, Mars — bferrari @ 9:22 pm
NASA's Viking landers carried four instruments designed to search for signs of Martian life: a gas chromatograph/mass spectrometer, as well as experiments for gas exchange, labeled release and pyrolytic release. It may have been successful.

NASA's Viking landers carried four instruments designed to search for signs of Martian life: a gas chromatograph/mass spectrometer, as well as experiments for gas exchange, labeled release and pyrolytic release. It may have been successful.

NASA’s Viking landers may have detected the ingredients for life on Mars after all, according to a new study.

Back in the 1970s, the two Viking probes scooped up and heated Martian dirt, then looked for organic molecules — the carbon-based building blocks of life as we know it — in the samples. The landers found little, aside from two strange chlorine compounds that researchers at the time attributed to contamination from cleaning fluids.

But the new study suggests that the soil did indeed contain organics, which can have biological or nonbiological origins. They were just destroyed before Viking could detect them.

“This result is saying that there are organic molecules on Mars,” study co-author Chris McKay, of NASA’s Ames Research Center in Moffett Field, Calif., told SPACE.com. “It doesn’t say anything about life now, or life in the past. But it does open up the possibility of searching for organic molecules produced by life, and that’s very exciting.”

Accounting for perchlorate

A 2008 find by NASA’s Phoenix Mars lander helped motivate McKay and his colleagues, led by Rafael Navarro-Gonzalez of the National Autonomous University of Mexico, to take another look at the Viking results.

Phoenix detected a chlorine-containing chemical called perchlorate at its landing site, near the Martian north pole. The researchers suspected that perchlorate may have produced what Viking found, destroying original soil organics and leaving behind the two chlorinated compounds, chloromethane and dichloromethane.

So the scientists performed a lab experiment. They grabbed some dirt from Chile’s Atacama Desert — widely considered to be a Martian analog

environment — and spiked it with perchlorate. Then they heated the mixture up in the lab, just as the Viking landers did on Mars.

Just as with Viking, the researchers found chloromethane and dichloromethane.

“The simplest, most reasonable explanation of the Viking results is that there were organics in the soil, and they were consumed by the perchlorate,” McKay said. “I think it’s pretty convincing.”

Navarro-Gonzalez, McKay and their colleagues reported their findings last month in the Journal of Geophysical Research – Planets, though the results were first announced last September.

Not proof of life

The results don’t prove that life exists — or ever existed — on Mars. While organics are associated with life here on Earth, that’s not necessarily the case elsewhere in the solar system, McKay said.

Organic compounds seem to be common, for example, on asteroids, comets and the icy bodies orbiting the sun in the Kuiper Belt, beyond Neptune.

But the prospect of Martian life may be a bit more likely now, since Viking seemingly found life’s building blocks in the planet’s red dirt more than three decades ago.

“There’s a possibility that some of those organic molecules are in fact biomarkers,” or indications of the presence of life, McKay said. “That’s exciting.”

Following up with the next Mars rover

Scientists should soon get a chance to confirm the presence of organics in Mars’ soil. NASA’s Mars Science Laboratory (MSL) rover, also known as Curiosity, is slated to land on the Red Planet in August 2012. As part of its mission to determine Mars’ potential to host life — either today or in the past — the car-size rover will search for organic molecules.

MSL’s instruments will attempt to extract organics using heat, like Viking did. But the new rover will also use a liquid method, which should clear things up; perchlorate doesn’t destroy organic molecules if it’s not heated to high temperatures.

“My prediction is that MSL, when it does the heat mode, will see nothing,” McKay said. “But when it does the liquid extraction mode, it will see the organics.”

Should MSL indeed confirm organics on Mars, the next step would likely be to figure out if they have a biological or nonbiological origin. That may require another mission, according to McKay.

“If MSL finds an interesting diversity and complexity of organics, then we could do a follow-up mission that’s targeted to look for biologically formed organic molecules,” McKay said. “That would be very interesting.”

*   6 Facts About NASA’s Next Mars Rover
*   Top 10 Martian Landings of All Time
*   Building Blocks for Life on Mars Possibly Seen By Viking Probes, Study Suggests

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