Scientists Discover Universe’s Largest Known Structure

Posted January 14th, 2013 at 7:27 pm (UTC+0)

Artist’s impression of a very distant quasar powered by a black hole with a mass two billion times that of the Sun. (Image: ESO/M. Kornmesser via Wikimedia Commons)

Artist’s impression of a very distant quasar powered by a black hole with a mass two billion times that of the Sun. (Image: ESO/M. Kornmesser via Wikimedia Commons)

Scientists have found the largest known structure in the universe, a cluster of galactic cores so vast it would take four billion years for a spacecraft traveling at the speed of light to cross it.

The sighting challenges a theory from Einstein which suggests such a massive object shouldn’t exist in the universe.

A quasar is the compacted center of a galaxy surrounding a massive black hole from the early days of the universe.  Quasars  go through periods of extreme brightness which can last anywhere from 10 to 100 million years. They tend to band together in enormous clusters, or structures, forming large quasar groups (LQGs).

The international group of scientists led by Roger Clowes from the University of Central Lancashire’s Jeremiah Horrocks Institute, used data from the Sloan Digital Sky Survey (SDSS), a major surveying project that uses 2.5-m wide-angle optical telescope located at New Mexico’s Apache Point Observatory, to make their findings.

Clowes and his colleagues are astounded by the size of this structure, which defies the Cosmological Principal, based on Albert Einstein’s theory of General Relativity that assumes when you look at the universe from a sufficiently large scale; it looks the same no matter where you are observing it from.  The Cosmological Principle, according to the research team, is assumed but has never been demonstrated observationally ‘beyond reasonable doubt.’

LQG - Large quasar group as imaaged by the Big Throughput Camera at the Cerro Tololo Inter-American Observatory in Chile (Photo: Chris Haines)

Large quasar group (LQG) as imaged by the Big Throughput Camera at the Cerro Tololo Inter-American Observatory in Chile (Photo: Chris Haines)

“While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe,” said Clowes. “This is hugely exciting, not least because it runs counter to our current understanding of the universe. The universe doesn’t seem to be as uniform as we thought.”

Clusters of galaxies can be anywhere from six to 10 million light-years across, but the LQGs can be 650 million light-years or more across. Making calculations based on the Cosmological Principle, along with the modern theory of cosmology, astrophysicists shouldn’t be able to find a structure in the universe larger than 1.2 billion light-years, much less four billion light-years across as this newly sighted structure is.

To get some additional perspective of what the astronomers found, let’s step back and give it a sense of scale.  Our own galaxy, the Milky Way, is separated from its nearest neighbor, the Andromeda Galaxy, by a distance of 2.5 million light-years.

Clowes points out that his team’s discovery does have a typical dimension of 1.6 billion light-years. But, because it is elongated, its longest dimension is four billion light-years, making it about 1,650 times larger than the distance from the Milky Way to Andromeda.

Apple’s iPhone Turns 6

Posted January 11th, 2013 at 7:53 pm (UTC+0)
1 comment

The first Apple iPhone was introduced on January 9, 2007 and went on sale in June 2007. Here's the original iPhone sitting in it's charging dock.  (Photo: Andrew via Wikimedia Commons)

The first Apple iPhone was introduced on January 9, 2007 and went on sale in June 2007. Here’s the original iPhone sitting in it’s charging dock. (Photo: Andrew via Wikimedia Commons)

On Wednesday, January 9, the iPhone turned 6 years old. On that day in 2007 Apple’s late visionary leader Steve Jobs took the stage at the Macworld Expo in San Francisco to address the Apple faithful about a new and highly anticipated product the company was unveiling.

Describing it as a “leap frog product that is way smarter than any mobile device that has ever been and super easy to use,” Jobs introduced the first iPhone to the world.

It wasn’t the very first smartphone – some in the communications industry credit IBM’s Simon Personal Communicator released in 1994 as the first – nor was it the only smartphone on the market at the time – in 2007, Blackberry and Palm devices were all the rage. But the release of Apple’s iPhone really caught the public’s attention and took the smartphone further into the mainstream with its advanced technology and multi-function abilities.

Apple boasted about the capabilities of its new device saying at the time that the iPhone combined three products into one—a new type of mobile phone, a widescreen iPod with touch controls, and an innovative Internet communications device that provided desktop-like email, web browsing, searching and maps.

People waited in line at an Apple Store for the release of the Apple iphone 5 on Sept. 21, 2012, at the Apple Store in Salt Lake City. People waited in line through the early morning to be among the first to get their hands on the highly anticipated phone. (Photo: AP)

People wait in line at an Apple Store, in Salt Lake City Utah, to be among the first to get their hands on the new iPhone 5 on Sept. 21, 2012. (Photo: AP)

Between its introduction in January and its release in June 2007, excitement took hold with the iPhone quickly becoming the “must have” device weeks before it even was put on sale.  The iPhone became an instant hit with consumers selling over a million devices within its first 74 days on the market, according to Apple.

In the years since, Apple has released newer versions of the iPhone that gave its users even more functionality. One of the most popular new features included the 2011 introduction of “Siri” in its iPhone 4S. Apple described Siri as “an intelligent assistant that helps you get things done just by asking.”  Siri interacts and communicates with the user through normal speech: a user just asks Siri a question and “she” answers back via a synthesized voice.

The first smartphone powered by the Android system was the HTC Dream that first went on sale in October 2008 (Photo: Marcus Sümnick via Wikimedia Commons)

The first smartphone powered by the Android system was the HTC Dream that first went on sale in October 2008 (Photo: Marcus Sümnick via Wikimedia Commons)

While Apple has sold millions of iPhones over the years, the popular smartphone has not been without its critics. For example, when it was first released in the US, Apple had an exclusive agreement with AT & T wireless, meaning the much coveted iPhone could only work on the AT & T wireless system. This arrangement didn’t sit too well with a lot of US consumers, saying it severely limited their choice of wireless carriers to just one. Other complaints about the iPhone since its initial release have included various difficulties that users had in operating the device or about a number of glitches or problems with issues such as software updates or the phones themselves.

As with any successful product, it didn’t take long until Apple competitors like Samsung, HTC, LG and others quickly sprang into action to develop and release their own advanced mobile devices they hoped would dethrone the iPhone as the most popular smartphone.

Despite the release of several imitators, Apple’s iPhone continued its reign as the top smartphone. But dark clouds were forming in the horizon for Apple as word of a new mobile phone operating system began to spread. The web-search engine giant Google had been talking about getting into the mobile telecommunications market since its 2005 acquisition of Android, Inc.; the company that designed and developed the new mobile device operating system. The buzz on the street at the time indicated that the new Android operating system just might be more advanced and superior to what Apple was running on its iPhone.

The popular Android powered Samsung Galaxy S III smartphone.  (Photo: Superzen via Wikimedia Commons)

The popular Android powered Samsung Galaxy S III smartphone. (Photo: Superzen via Wikimedia Commons)

The Android operating system was unveiled in November 2007; just five months after the first iPhones went on sale. The first mobile phone powered by the Android system, the HTC Dream, was released in October 2008.

Google offered the Android system with an open source code and a somewhat lenient licensing arrangement, making it much easier for software that would run on the Android system to be written, modified and distributed.

So far, according to recent research statistics, about 700,000 software applications or “apps” have been developed for mobile devices running on the Android system.   But, Apple continues to lead Android with a reported 1,000,000 apps developed for the iPhone.

The Android powered Samsung Galaxy S III and Apple’s iPhone 4S are two of the most popular smartphones being sold today.

The fight for market domination among smartphone manufacturers continues to fuel research and development of even much more advanced and sophisticated mobile devices.

Milky Way Contains Billions of Earth-sized Planets, Studies Find

Posted January 9th, 2013 at 6:29 pm (UTC+0)

The Milky Way - Looking up at the stars in our galaxy imagine that 1 out of 6 of them have an Earth-like planet orbiting it, according to two recently released studies (Photo: Steve Jurvetson via Wikimedia Commons)

One out of every six stars in our Milky Way galaxy has an Earth-like planet orbiting it, according to two new studies. (Photo: Steve Jurvetson via Wikimedia Commons)

There are at least 17 billion Earth-sized worlds in our Milky Way galaxy, according to two new studies.

Both groups of scientists used data from NASA’s Kepler mission to reach their conclusions, which were presented to the American Astronomical Society in Long Beach, California.

The scientists found that the closer the planets are to their stars, the easier they are to find because they transit more frequently, giving scientists more opportunities to observe them.

One group, led by Francois Fressin of the Harvard-Smithsonian Center for Astrophysics (CfA), said its studies show 50 percent of stars in our galaxy have a planet the size of Earth or larger closely orbiting them.

Add in larger planets, which have been found to be in wider orbits around its star, and the percentage of stars with planets goes up to 70 percent, according to the researchers.

Based on current ongoing observations from the Kepler mission, along with others using different detection techniques, it looks like practically all Sun-like stars have planets, according to the Harvard-Smithsonian team.

A second group of researchers, from the University of California, Berkeley and the University of Hawaii at Manoa, found smaller exoplanets to be much more plentiful than larger ones in the star systems it observed. The analysis also confirmed that the frequency of planets increased as its size decreased, which team member Andrew Howard and the Kepler team reported last year.

Perhaps one percent of stars have planets the size of Jupiter, while 10 percent have planets the size of Neptune, according to the Berkeley/ Hawaii team. The group’s research also shows the exoplanets they observed, which were two or three times the diameter of Earth, are typically more like our solar system’s Uranus and Neptune, each of which has a rocky core  surrounded by helium and hydrogen gases and, perhaps, water.

Artist's illustration represents the variety of planets being detected by NASA's Kepler spacecraft. A new analysis has determined the frequencies of planets of all sizes, from Earths up to gas giants. (Image: C. Pulliam & D. Aguilar (CfA))

Artist’s conception of the wide variety of planets detected by NASA’s Kepler spacecraft. (C. Pulliam & D. Aguilar/CfA)

They suggest planets orbiting close to their stars may even be water worlds, with oceans hundreds of kilometers deep, surrounding a rocky core.

Although the planets between one to two times larger than Earth may not necessarily be habitable,  the Berkeley/Hawaii team  said those planets might be rocky and, if they’re located within what they call the “Goldilocks zone” –not too hot, not too cold, just right for liquid water– could support life.

The Harvard-Smithsonian researchers found that, except for the gas giants, the type of star didn’t really have much effect on the size of its planets, contradicting previous findings. Neptune-type planets, they said, can be found just as frequently orbiting around relatively cool stars, called red dwarfs, as they are around sun-like stars. The same is true for smaller worlds.

“Earths and super-Earths aren’t picky,” said Guillermo Torres of the Harvard-Smithsonian team. “We’re finding them in all kinds of neighborhoods.”

As more data is gathered, more planets in larger orbits will be revealed, according to the Harvard-Smithsonian researchers. They say when Kepler’s mission is extended, astronomers should be able to spot Earth-sized planets at greater distances, including those with Earth-like orbits within the habitable zone.

Mars Meteorite Sparks New Questions About Red Planet

Posted January 7th, 2013 at 7:47 pm (UTC+0)

Designated Northwest Africa (NWA) 7034, and nicknamed "Black Beauty," the Martian meteorite weighs approximately 320 grams. (Photo: NASA)

The Martian meteorite known as “Black Beauty” weighs approximately 320 grams. (Carl Agee/University of New Mexico)

Scientists have determined a meteorite discovered in the Sahara Desert in 2011 is about 2.1 billion years old and could be the first meteorite to come from the surface of Mars.

The meteorite, designated NWA (North West Africa) 7034 and nicknamed “Black Beauty,” weighs about 320 grams and is loaded with Martian water. It is so uniquely different from other Martian meteorites that scientists say it is in a class of its own.

They believe Black Beauty, which contains 10 times more water than other Martian meteorites from unknown origins, formed during the beginning of the most recent geologic period on Mars, known as the Amazonian.

“The age of NWA 7034 is important because it is significantly older than most other Martian meteorites,” said Mitch Schulte, program scientist for the Mars Exploration Program at NASA headquarters in Washington. “We now have insight into a piece of Mars’ history at a critical time in its evolution.”

The NASA-funded team of scientists from various universities and institutions analyzed the mineral and chemical composition, age, and water content of the meteorite.

Black Beauty’s chemical composition includes organic carbon, which is similar to other Martian meteorites, known as SNC meteorites. However, other aspects of Black Beauty’s composition are very different.

“The texture of the NWA meteorite is not like any of the SNC meteorites,” said Andrew Steele, who led the carbon analysis at the Carnegie Institution’s Geophysical Laboratory. “This is an exciting measurement in Mars and planetary science. We now have more context than ever before to understanding where they may come from.”

Black Beauty, according to the research team, is made of cemented fragments of basalt, rock  formed from rapidly-cooled lava. The fragments are primarily feldspar and pyroxene, most likely from volcanic activity.

NASA Funded scientists have found that the NWA 7034 meteorite came from the surface or crust of Mars - photo taken by the Mars rover, Spirit (Photo: NASA)

Scientists say the Black Beauty meteorite came from the surface, or crust, of Mars (NASA)

“This Martian meteorite has everything in its composition that you’d want in order to further our understanding of the Red Planet,” said Carl Agee, leader of the analysis team and director and curator at the University of New Mexico’s Institute of Meteoritics in Albuquerque. “This unique meteorite tells us what volcanism was like on Mars two billion years ago. It also gives us a glimpse of ancient surface and environmental conditions on Mars that no other meteorite has ever offered.”

Up until now,  SNC meteorites have been the only meteorite samples from the Red Planet  scientists have been able to study, however, their exact point of origin on Mars isn’t  known.  Scientists say recent data from NASA Mars lander and orbiter missions indicate the SNC meteorites are actually a mismatch with the Martian crust.

But Black Beauty does match up with surface rocks and outcrops studied by NASA’s Mars rovers, such as Curiosity, Opportunity and Spirit, as well as its orbiting satellites, like the Mars Odyssey Orbiter.

“The contents of this meteorite may challenge many long-held notions about Martian geology,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “These findings also present an important reference frame for the Curiosity rover as it searches for reduced organics in the minerals exposed in the bedrock of Gale Crater.”

Alan Alda’s Challenge to Scientists

Posted January 4th, 2013 at 11:47 pm (UTC+0)

Professor Alan Alda (Photo: Center for Communicating Science, Stony Brook University)

Professor Alan Alda (Photo: Center for Communicating Science, Stony Brook University)

Alan Alda, the internationally famous TV/movie actor, director and writer, is looking for answers to a question we’ve all pondered at some point in our lives – what is time?  So he recently issued a challenge to the world’s scientists to come up with a good explanation.

While the question alone might stump even the brightest of scientists, Alda’s challenge also has a catch.  The explanation must be made so that an 11-year-old can easily understand it.

Science World recently spoke with Alan Alda to learn more about his challenge.  He told us that when he was just 11 years old, he found himself becoming quite fascinated with the flame burning at the end of a candle.

Curious about what a flame was, Alda decided to ask his teacher – “what’s a flame?”  He was hoping for a clear and concise answer to his question, but the teacher instead came back at him with just a one word answer – oxidation.

Needless to say, young Alan was quite dissatisfied with his teacher’s answer and was frustrated that he still didn’t know what a flame was.

In spite of the teacher’s terse answer to his query, Alda continued to have a lifelong interest in science.

While he’s best known for playing the wisecracking surgeon Dr. Benjamin “Hawkeye” Pierce, M.D. on the classic TV show M*A*S*H, Alda also hosted the TV series “Scientific American Frontiers” that aired on the U.S. public television network PBS.

Throughout the course of hosting that TV show, Alda said that he had the chance to interview hundreds of scientists.  In doing so, he discovered that many of the scientists he spoke with had wonderful stories to tell, but some needed help in telling them.

Alda also concludes that the scientists themselves are recognizing that they need to become better communicators, and that there are three big groups of people that need to be communicated with better.

What is time??? (Image: The Flame Challenge/Center for Communicating Science, Stony Brook University)

What is time??? (Image: The Flame Challenge/Center for Communicating Science, Stony Brook University)

The first group is the general public. Alda says the public needs to have a clear understanding of science because they’re using it every day. And because they may not quite understand it, he says people aren’t asking the right questions and sometimes that creates barriers to better science.

The second group of people, according to Alda, includes legislators and policy makers.  “They routinely don’t understand what the scientists are asking funding for; they don’t understand it at a deep enough level anyway,” he said.

The third group that Alda said can really benefit from better science communication is that of fellow scientists — those who sometimes aren’t familiar with scientific disciplines other than their own. “So that’s holding back collaboration, I would think, holding back new inroads that can be made because an awful lot of things happening now, that are breaking ground, require the collaboration of a lot of people from a lot of different fields,” Alda said.

So to help scientists and health professionals develop the skills needed to become effective communicators, Alda helped create the Center for Communicating Science at Stony Brook University in New York, where he is also a visiting professor.

His passion for communicating science to others also came through while writing a guest editorial for the journal Science.

“I realized that I had a personal story to tell about communicating science and it was that story about my teacher not really explaining the flame very well.  And then I realized by the end of the article that I had a contest and I challenged scientists to come up with an explanation an 11-year-old could understand.”

1972 photo of Alan Alda as the wisecracking but loveable Dr. Benjamin "Hawkeye" Pierce" on the TV series M*A*S*H.  (Photo: CBS Television [Public domain], via Wikimedia Commons)

1972 photo of Alan Alda as the wisecracking but loveable Dr. Benjamin “Hawkeye” Pierce on the TV series M*A*S*H. (Photo: CBS Television [Public domain], via Wikimedia Commons)

That challenge wound up being the first in what Alda and his colleagues at the Stony Brook University have called “The Flame Challenge.”

From over 800 entries submitted, 31-year-old Ben Ames, an American studying for his Ph.D in Austria, won the first “Flame Challenge” last year with his animated video explanation of “What is a flame?”

A couple of weeks ago, Alda issued his second “Flame Challenge.”  The question this time came from actual 11 year-old students.  Like the first “Flame Challenge” question, this one also is very basic – but it’s also quite perplexing and one that might be difficult for scientists to explain to the young students. The question: “What is time?”

According to the “Flame Challenge” website, entries can either be written, or in video or graphic forms.

Scientists competing in the “Flame Challenge” have till 0459 UTC March 2, 2013, to get their entries in. The judging will be done by thousands of 11-year-olds.

Alda says that judging the contest has been a big hit with the young scientists of the future.  “They really love the chance to take a serious position in deciding what’s a good explanation and they are very serious about it,” he said.

While the “Flame Challenge” question alone could be difficult to answer, why does the explanation have to be understood by 11-year-olds in particular?

“It just happened that way, because I was 11 when I asked that question,” explained Alda.  “It turns out that, as we look at 11-year-olds who are judging it, it seems they have a kind of special ability, they’re in a special place in their lives where they still have the curiosity, a sort of unbridled curiosity of a kid, but they’re beginning to take on the critical thinking of an adult, so they’re in a good position to both asked the question and judge the answer,” he said.

Professor Alda helps Scientists to communicate more effectively. (Photo: Center for Communicating Science, Stony Brook University)

Professor Alda helps scientists communicate more effectively. (Photo: Center for Communicating Science, Stony Brook University)

Videos of the youngsters reviewing answers that were submitted for last year’s challenge revealed just how serious they were about their judging duties.  “They say things like, ‘this is too short, it doesn’t have enough information,’” Alda said.  “And one kid was great, he said that ‘we like them if they’re entertaining, but this is silly.’  He said that ‘We’re 11, not seven,’ and I loved that very grown up approach to this old question.”

Schools around the world can also take part in the “Flame Challenge” by getting their 11-year-old students involved with judging.

For details on how scientists can take on the challenge, and how 11-year-olds can become judges, just visit the “Flame Challenge” website.

Alan Alda joins us this weekend on the radio edition of Science World.  He talks about the “Flame Challenge” and why it’s important for scientists to be good communicators.   For broadcast times please check the right column.

You can listen below to hear the full Science World interview with Alan Alda.

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Mars Mission Could Accelerate Alzheimer’s in Astronauts

Posted January 2nd, 2013 at 8:23 pm (UTC+0)

Artist's rendition of astronauts on Mars. (Image: NASA).

Artist’s rendition of astronauts on Mars. (NASA)

Traveling into deep space could accelerate the onset of Alzheimer’s disease, an incurable form of dementia, according to a new report.

The NASA-funded study assessed how cosmic radiation would impact the astronauts throughout their trip in deep space. The effect of cosmic radiation on the human body has been a  concern for the US space agency as it plans manned missions into deep space, such as one to a distant asteroid in 2021, and another to Mars in 2035.

Earth’s magnetic field usually keeps us, and those in low Earth orbit, safe from the perils of cosmic radiation. However, beyond Earth’s protective magnetic fields, space travelers are exposed to a constant barrage of radiation.

With adequate warning, such as in the case of solar flares, steps can be taken to protect astronauts from dangerous forms of radiation. However, other forms of cosmic radiation, which occur without warning, cannot be blocked as effectively.

“Galactic cosmic radiation poses a significant threat to future astronauts,” said M. Kerry O’Banion,  a professor in the University of Rochester Medical Center (URMC) and senior author of the study. “The possibility that radiation exposure in space may give rise to health problems such as cancer has long been recognized. However, this study shows for the first time that exposure to radiation levels equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer’s disease.”

Artist's illustration of the shape and function of the Earth's magnetic field that protects us from harmful cosmic radiation (Image: NASA)

Artist’s illustration of the shape and function of the Earth’s magnetic field that protects us from harmful cosmic radiation (NASA)

In the past,  scientists studied the impact of cosmic radiation on a living being’s cardiovascular and musculoskeletal systems, as well as potential risks of contracting various forms of cancer.But the new study,  published in  PLOS ONE, examined the possible effects of space radiation on neurodegeneration, a gradual loss of brain structure or function.

For this study, researchers wanted to find out what role, if any, cosmic radiation plays in accelerating the biological and cognitive indicators of Alzheimer’s disease, especially in those  predisposed to developing the illness.

They specifically wanted to learn more about the impact of radiation from high-mass, high-charged (HZE) particles, which come in many forms and travel through space with the force of exploding stars.

Instead of examining hydrogen protons, which are produced by solar flares, the researchers decided to study iron particles. They say HZE particles, such as iron, when combined with their high rate of speed, are able to go through solid objects, like a spacecraft’s walls and protective shielding.

“Because iron particles pack a bigger wallop, it is extremely difficult, from an engineering perspective, to effectively shield against them,” said O’Banion. “One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.”

Brain affected by Alzheimer's Disease (left) vs Normal Brain (right) - (Image: US Dept of Veterans Affairs)

Brain affected by Alzheimer’s Disease (left) vs normal brain (right) – (US Dept of Veterans Affairs)

The researchers exposed mice to various doses of radiation, including levels that would be similar to what astronauts would experience during deep space voyages.To evaluate the cognitive and biological impact of the radiation exposure, the mice were then put through a series of experiments in which they had to recall objects or specific locations. Researchers observed that the radiation- exposed mice were much more likely to fail these tests, suggesting neurological impairment, earlier than the symptoms would typically appear.

Along with symptoms of neurological damage, the researchers found that the mice’s brains also showed signs of vascular changes and had a greater than usual buildup of beta amyloid, the protein “plaque” that gathers in the brain and is one of the characteristics of Alzheimer’s Disease.

“These findings clearly suggest that exposure to radiation in space has the potential to accelerate the development of Alzheimer’s disease,” said O’Banion. “This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions.”

Satellite’s Space Trip Ends After 30 Years

Posted December 28th, 2012 at 7:45 pm (UTC+0)
1 comment

Artist drawing of Landsat-5 in space (Image: USGS)

Artist drawing of Landsat-5 in space (Image: USGS)

The longest operating Earth-observing satellite is about to be decommissioned by the US Geological Survey.

The USGS has begun the task of lowering Landsat-5 from its operational orbit.  The first series of maneuvers in that effort is likely to take place within the next month.

Landsat-5 was the fifth of seven satellites launched as part of the Landsat program, which has been acquiring satellite imagery of Earth since 1972.

Launched from California on March 1, 1984, Landsat-5 has circled Earth more than 150,000 times.

According to the USGS, which helps manage the mission, the satellite has been an extraordinary success, providing valuable contributions to the global record of land change.

Its original mission was only supposed to last three years, but Landsat-5 continued to deliver imagery and data for more than 25 more years beyond that.

The satellite experienced a number of problems over the years, but scientists and technicians managed to bring it back from the brink of failure.

This image of the abandoned city of Pripyat, home to the Chernobyl Nuclear Power Plant was taken by Landsat-5 three days after the April 26, 1986, nuclear accident. (Image: NASA GSFC Landsat/LDCM EPO Team)

This image of the abandoned city of Pripyat, home to the Chernobyl Nuclear Power Plant was taken by Landsat-5 three days after the April 26, 1986, nuclear accident. (NASA)

However, the recent failure of one of its gyroscopes proved to be one problem too many, finally bringing Landsat-5′s decades-long mission to an end.

“This is the end of an era for a remarkable satellite, and the fact that it flew for almost three decades is a testament to the NASA engineers and the USGS team who launched it and kept it flying well beyond its expected lifetime,” said Anne Castle, Department of the Interior assistant secretary for Water and Science. “The Landsat program is the gold standard of satellite observation, providing an invaluable public record of our planet that helps us tackle critical land, water, and environmental issues.”

Over more than a quarter of a century, Landsat-5  observed and sent back Earth imagery and data  reflecting the many changes which have taken place on our planet, not only from natural hazards and a changing climate, but also due to land use practices.

It observed the eruption of Mount Saint Helens, the 1991 Kuwaiti oil fires set by a fleeing Iraqi military, the 1986 Chernobyl nuclear disaster, as well as rainforest depletion, wildfires, floods, global crop production, and the expansion and retreat of the Earth’s ice shelves.

Image taken by Landsat-5 in 1991 shows inky-black smoke pouring into the atmosphere from burning oil wells as defeated Iraqi military forces set fire to oil wells as they retreated from Kuwait. (Image: NASA GSFC Landsat/LDCM EPO Team)

Image taken by Landsat-5 in 1991 shows inky-black smoke pouring from burning oil wells which were set afire by defeated Iraqi military forces as they retreated from Kuwait. (NASA)

“Any major event since 1984 that left a mark on this Earth larger than a football field was likely recorded by Landsat-5, whether it was a hurricane, a tsunami, a wildfire, deforestation, or an oil spill,” said USGS Director Marcia McNutt. “We look forward to a long and productive continuation of the Landsat program, but it is unlikely there will ever be another satellite that matches the outstanding longevity of Landsat-5.”

Landsat-5 observations have helped increase our understanding and awareness of the impact humans have on the land, according to the USGS.

With Landsat-5 out of commission, a number of Earth-observing satellites put into space by other governments and private companies, continue to operate.

Landsat-7, which launched in 1999, and the upcoming  Landsat-8 (LDCM), which launches in 2013, will take up where Landsat-5 left off, continuing to keep watch over an ever-changing planet.

Science Images of the Week

Posted December 26th, 2012 at 3:59 pm (UTC+0)
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NASA's Cassini spacecraft recently delivered a spectacular view of Saturn, taken while the spacecraft was in Saturn's shadow. The cameras were turned toward Saturn and the sun so that the planet and rings are backlit. (Image: NASA/JPL-Caltech/Space Science Institute)

NASA’s Cassini spacecraft recently snapped this spectacular view of Saturn, taken while the spacecraft was in Saturn’s shadow. The cameras were turned toward Saturn and the Sun so that the planet and rings are backlit. (NASA)

A sabal causiarum, commonly known as the Puerto Rican hat palm was planted in 1932 at the Montgomery Botanical Center in Coral Gables Florida.  (Photo: P. Barry Tomlinson, National Tropical Botanical Garden, Miami/American Journal of Botany)

This sabal causiarum, commonly known as the Puerto Rican hat palm, was planted in 1932 at the Montgomery Botanical Center in Coral Gables Florida. (P. Barry Tomlinson, National Tropical Botanical Garden, Miami/American Journal of Botany)

This is an instrument setup for an astrophysics experiment at the SLAC National Accelerator Laboratory's Linac Coherent Light Source (LCLS), a linear accelerator that produces X-ray pulses that can capture images of atoms and molecules in motion. (Photo: Jose R. Crespo Lopez-Urrutia/Max Planck Institute for Nuclear Physics)

This linear accelerator produces x-ray pulses that capture images of atoms and molecules in motion and is for an astrophysics experiment at the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS),. (Jose R. Crespo Lopez-Urrutia/Max Planck Institute for Nuclear Physics)

This photo, taken recently at a slow shutter speed shows lava flowing down central Ecuador's Tungurahua volcano.(AP Photo/Dolores Ochoa)

Lava flows down central Ecuador’s Tungurahua volcano in this photo taken at a slow shutter speed. (AP)

This is a map of the moon's gravity field as measured by NASA's Gravity Recovery and Interior Laboratory (GRAIL). The two spacecraft that carried out the GRAIL mission was recently crashed into the surface of the Moon by the US space agency. (Image: NASA/JPL-Caltech/MIT/GSFC)

A map of the moon’s gravity field, as measured by NASA’s Gravity Recovery and Interior Laboratory (GRAIL). Areas colored in red have a high degree of local gravity, the blue blotches show lower local gravity, and other colors indicate varying degrees of local gravity in between red and blue. (NASA)

This is a diamond anvil cell (DAC). This device has been used in experiments by scientists to recreate the pressure that exists deep inside planets. (Photo by Roy Kaltschmidt, Berkeley Lab)

Scientists use this device, a diamond anvil cell (DAC), in experiments to recreate the pressure that exists deep inside planets. (Roy Kaltschmidt, Berkeley Lab)

Looking like a brightly colored holiday ribbon, here's a striking image of the planetary nebula, NGC-5198 taken recently by the Hubble Space Telescope.  (Image: NASA, ESA and the Hubble Heritage Team (STScI/AURA))

This striking image of the planetary nebula NGC-5198, was taken by the Hubble Space Telescope. (NASA)

The six huge fans shown here provide the wind for the wind tunnel at NASA's National Full-scale Aerodynamics Complex in California (Photo: NASA Ames/Tom Trower)

These six huge fans provide wind for the wind tunnel at NASA’s National Full-scale Aerodynamics Complex in California. (NASA)

This is a hawksbill sea turtle. It's an endangered animal and is one of seven species of the world's sea turtles. It's shell is made up of overlapping plates that are thicker than those of other sea turtles. This heavy duty shell protects them from being battered. (Photo: Caroline S. Rogers/NOAA)

This endangered hawksbill is one of seven species of the world’s sea turtle. Its shell is made up of overlapping plates which are thicker than those of other sea turtles. This heavy-duty shell protects them from being battered. (NOAA)

Here's another interesting volcano photo that was taken from the International Space Station.  The huge plume of smoke is from the erupting volcano Ulawan located on the island of New Britain, Papua New Guinea. (Photo: NASA)

In a photo captured from the International Space Station, a mammoth plume of smoke emanates from the erupting Ulawan volcano, located on the island of New Britain, Papua New Guinea. (NASA)

Scientists Strike ‘Scientific Gold’ in California

Posted December 21st, 2012 at 6:58 pm (UTC+0)

Fragments of the Sutter’s Mill meteorite fall collected by astronomer Dr. Peter Jennisken. (Photo:  NASA/Eric James)

Fragments of the Sutter’s Mill meteorite fall collected by astronomer Dr. Peter Jennisken. (NASA)

Researchers have struck scientific gold at Sutter’s Mill, site of the famed California Gold Rush where the precious metal was first discovered in 1848.

In April of this year, the scientists recovered a rare meteorite which contains clues to the early history of the solar system.

Using Doppler radar, the same technology used by weather forecasters, the scientists detected a shower of meteors raining down over the communities of Coloma and Lotus, just after the asteroid broke up in the atmosphere.

That allowed scientists to, for the first time,  quickly find, recover and study a primitive meteorite that had little exposure to the elements.

It’s the most pristine look at the surface of ancient asteroids scientists have been able to study so far. Because of the rapid recovery of materials, scientists were able to detect compounds that quickly disappear once a meteorite hits Earth.

Reporting in Science, the researchers say their rare find was classified as a Carbonaceous-Mighei or CM-type carbonaceous chondrite meteorite, which is known to contain water and complex organic compounds, such as amino acids, molecules that help form life.

But, according to NASA’s Danny Glavin, he and the other scientists weren’t able to detect many of the amino acids in their find because it appeared the samples had been heated in space before arriving on Earth.

“The small three meter-sized asteroid that impacted over California’s Sierra Nevada came in at twice the speed of typical meteorite falls,” said lead author Peter Jenniskens, of the SETI Institute and NASA’s Ames Research Center, both located in California. “Clocked at 64,000 miles per hour, it was the biggest impact over land since the impact of the four meter-sized asteroid 2008 TC3, four years ago over Sudan.”

The scientists also say that, for the first time, they were able to identify the region of space where these types of meteorites come from.

After studying photographs and video of the asteroid, Jenniskens figured that it came in on an unusually low-angled orbit, more like a comet‘s orbit, passing closer to the sun than what has been learned from past recorded meteorite falls.

Scientists found the asteroid, as it was in orbit, was influenced by the gravity of both the Sun and Jupiter at times.

“It circled the sun three times during a single orbit of Jupiter, in resonance with that planet,” Jenniskens said.

A meteor flashes across the sky during the peak of the November 2009 Leonid Meteor Shower. (Photo: Ed Sweeney via Wikimedia Commons)

A meteor flashes across the sky during the peak of the November 2009 Leonid Meteor Shower. (Photo: Ed Sweeney via Wikimedia Commons)

The asteroid that spawned the meteorite was estimated to be around 45359 kg.  Of that, less than 1kg was actually recovered on the ground in the form of 77 tiny meteorites. The biggest of those meteorites was 205 grams.

While the scientists didn’t find much actual gold in the Sutter’s Mill meteorite, about 150 parts per billion, it was still “scientific gold,” according to co-author and cosmochemist Qing-zhu Yin of the University of California at Davis.

“With 78 other elements measured, Sutter’s Mill provides one of the most complete records of elemental compositions documented for such primitive meteorites,” he said.

Study: Human Hand Evolved So Fist Could Club Enemies

Posted December 19th, 2012 at 11:09 pm (UTC+0)

A clenched human fist ((Photo: Ralpharama via Wikimedia Commons)

A clenched human fist (Photo: Ralpharama via Wikimedia Commons)

The human hand is a sophisticated work of art and science. Refined through centuries of evolution, hands enable us to perform unique functions which help us to not only survive but also to thrive as a species.

New research suggests the evolution of the modern human hand may be due to a very basic need: for use as a weapon.

In a study published in The Journal of Experimental Biology,  University of Utah scientists theorize human hands evolved their unique square palms and long thumb in order to stabilize the fist, providing a built-in compact club early humans could use in combat.

An impassioned conversation with a colleague inspired David Carrier to pursue research on the matter.

In the course of their conversation, Frank Fish, an expert in biomechanics, formed a fist and said, “I can hit you in the face with this, but that is not what it evolved for.”

Fish’s proclamation made Carrier stop and think. While the human hand evolved to allow great dexterity, according to Carrier, a chimpanzee can also manipulate its hands in a way that would give it greater manual dexterity, but they still may not necessarily be able to form their hands like humans do.

Modern chimpanzees, according to Carrier, have long palms and fingers with a short thumb, while the human palm and fingers are much shorter and the thumb longer and stronger.

Three views of a clenched human fist show how we buttress the fist to reduce the chance of hand injury when punching. (Photo: Denise Morgan for the University of Utah)

Three views of a clenched human fist show how we buttress the fist to reduce the chance of hand injury when punching. (Photo: Denise Morgan for the University of Utah)

This difference brought on by evolution, allows us to clench our hand into a fist whenever we fold our thumb across the fingertips.  A chimpanzee’s fingers, on the other hand, forms the shape of what he describes as an open doughnut shape when curled.

Carrier said that he wondered if the tightly-packed human fist provides some internal support to our fingers in order to protect them from being damaged during an altercation and if it also provides humans with the ability to deliver a more powerful blow against their opponents, as compared to the slap of an open hand.

Carrier and Morgan decided to find out whether hands are more effective when balled into a fist or used as an open-handed slap.

“Fortunately, Michael had a lot of experience with martial arts and he knew people who were willing to serve as subjects,” said Carrier.

First, the test subjects were asked to smack a punching bag with their hands formed into a wide variety shapes; from the open-handed slap to the tightly-clenched fist, using various styles to deliver the blows, such as over the arm, sideways and head on. As each of the fighters walloped their punching bag foe, the researchers would measure the force of each impact.

But after looking at the results of that experiment, the researchers were surprised to see the punch did not deliver more force per blow.

“In terms of the peak forces or the impulse, it did not matter whether the subjects were hitting with a clenched fist or open palm,” said Carrier.

With fists only a human hand can form, a fighter delivers a devestating punch to her opponent. (Photo: Courtney "Coco" Mault/Wikipedia Commons via Flickr)

Fists formed only by a human hand can be used as a weapon without causing injury to the person delivering the punch. (Photo: Courtney “Coco” Mault/Wikipedia Commons via Flickr)

Morgan and Carrier then wanted to find out whether supporting the hand, by curling the fingers and thumb, stiffens the structure of the hand. Asking their test subjects to form their hands into various fist shapes, the researchers measured the rigidity of the first knuckle joint of their subject’s index finger, first with the support of the thumb over the finger and then without the support of the thumb. They found the knuckle joint was four times more rigid when supported by the thumb.

Next, the researchers measured the amount of force that the fighters could deliver through the fist surface of their index and middle fingers. Again, they found that by using the thumb in forming a fist, the test subjects doubled the delivered force by transmitting it to the wrist through the palm bones of the thumb and the index finger.

The results of their experiments led Carrier and Morgan to conclude  the square-shaped palms of today’s humans are perfectly proportioned to stiffen into a fist to be used as a weapon that delivers powerful punches without injuring ourselves.

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