ESA Planck Telescope: Sky Survey changes date on early stars

Planck has mapped the delicate polarisation of the CMB across the entire sky

Scientists working on ESA's Planck satellite say the first stars in the Universe lit up later than was previously thought.

The team has made the most precise map of the "oldest light" in the cosmos.

Earlier observations of this radiation had suggested that the first generation of stars burst into life about 420 million years after the Big Bang.

The new Planck data now indicates they fired up around 560 million years after the Universe got going.

"This difference of 140 million years might not seem that significant in the context of the 13.8-billion-year history of the cosmos, but proportionately it's actually a very big change in our understanding of how certain key events progressed at the earliest epochs," said Prof George Efstathiou, one of the leaders of the Planck Science Collaboration.

Subtle signal
The assessment is based on studies of the "afterglow" of the Big Bang, the ancient light called the Cosmic Microwave Background (CMB), which still washes over the Earth today.

The European Space Agency's (ESA) Planck satellite mapped this "fossil" between 2009 and 2013.

It contains a wealth of information about early conditions in the Universe, and can even be used to work out its age, shape and do an inventory of its contents.

Scientists can also probe it for very subtle "distortions" that tell them about any interactions the CMB has had on its way to us.

Forging elements
One of these would have been imprinted when the infant cosmos underwent a major environmental change known as re-ionisation.

It is when the cooling neutral hydrogen gas that dominated the Universe in the aftermath of the Big Bang was then re-energised by the ignition of the first stars.

These hot giants would have burnt brilliant but brief lives, producing the very first heavy elements. But they would also have "fried" the neutral gas around them - ripping electrons off the hydrogen protons.

And it is the passage of the CMB through this maze of electrons and protons that would have resulted in it picking up a subtle polarisation.

Impression: The first stars would have been unwieldy behemoths that burnt brief but brilliant lives

The Planck team has now analysed this polarisation in fine detail and determined it to have been generated at 560 million years after the Big Bang.

The American satellite WMAP, which operated in the 2000s, made the previous best estimate for re-ionisation at 420 million years.

The problem with that number was that it sat at odds with Hubble Space Telescope observations of the early Universe.

Hubble could not find stars and galaxies in sufficient numbers to deliver the scale of environmental change at the time when WMAP suggested it was occurring.

Planck's new timing "effectively solves the conflict," commented Prof Richard McMahon from Cambridge University, UK.

"We had two groups of astronomers who were basically working on different sides of the problem. The Planck people came at it from the Big Bang side, while those of us who work on galaxies came at it from the 'now side'.

"It's like a bridge being built over a river. The two sides do now join where previously we had a gap," he told reporters.

That gap had prompted scientists to invoke complicated scenarios for how re-ionisation could have occurred, including the ideas that there were an even earlier population of giant stars or energetic black holes. Such solutions are no longer needed.

The finding is also good news for the next generation of observatories like the James Webb Space Telescope, which will have the power to see right through the epoch of re-ionisation.

NASA Mars Opportunity Rover: Changes to non-Flash Memory usage

Persistent computer resets and "amnesia" events on NASA's Mars Exploration rover Opportunity that have occurred after reformatting the robot's flash memory have prompted a shift to a working mode that avoids use of the flash data-storage system.

The most recent reformatting of Opportunity's flash memory was last week.

Following that, performance of the flash memory remained intermittent, and difficulty in placing data into the memory led to computer resets during the weekend.

Flash memory retains information even when power is shut off during the rover's overnight power-conserving "sleep" time.

In the no-flash mode, the rover can continue normal operations of science observations and driving, though it cannot store data during the overnight sleep.

Data gathered each Martian day is stored in volatile memory, which on Opportunity is random-access memory (RAM). That data stored in volatile memory is relayed Earthward before sleep because it is lost when power goes off.

The team is developing a set of commands to restore usability of the flash memory through an overhaul more extensive than the reformatting that has been used so far.

The incidents of Opportunity's flash memory not accepting data for storage have occurred in only one of the seven banks of flash microchip circuitry on board. The team plans to send commands for the rover to avoid that entire bank.

"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, California.

"While we're operating Opportunity in that mode, we are also working on an approach to make the flash memory usable again."

"We will be sure to give this approach exhaustive reviews before implementing those changes on the rover."

Opportunity is examining outcrops on the western rim of Endeavour Crater while traversing southward toward "Marathon Valley," where clay minerals have been detected in observations by NASA's Mars Reconnaissance Orbiter.

Boeing 777 and 737 cockpit display change: WiFi threat to pilots' display

The affected Boeing control panel displays are susceptible to interference from Wi-Fi devices intended for routine use by many pilots during flights, according to the FAA document. 

Credit: Getty Images

New electronic display units are to be fitted in the cockpits of Boeing 737 and 777 airliners to address fears that Wi-Fi signals might cause them to go blank in flight.

In an airworthiness directive published Wednesday, the Federal Aviation Administration (FAA) said the switchover involves 1,149 late-model 737s and 177 777s in the United States alone.

The Federal Aviation Administration's safety directive, released Tuesday, aims to ensure that essential information such as airspeed, altitude and heading doesn't temporarily disappear from certain instrument displays manufactured by Honeywell International Inc.

Each installation is estimated to cost about $10,000, said the agency, which set a five-year deadline for the work to be completed.

"We are issuing this (directive) to prevent loss of flight-critical information displayed to the flight crew during a critical phase of flight, such as an approach or takeoff," it said.

Such an incident "could result in loss of airplane control at an altitude insufficient for recovery, or controlled flight into terrain," it added.

Display units are computer screens that give pilots vital in-flight information, such as altitude, airspeed, compass heading and the aircraft's attitude relative to the horizon.

The airworthiness directive—aviation's version of an automotive recall, was prompted by fears that Wi-Fi signals might interfere with a display unit, making it go blank.

Satellite Wi-Fi is being added to a growing number of commercial airliners, enabling passengers to log on to the Internet from 35,000 feet (10,000 meters).

In a statement, Honeywell International, which manufactures the display units, said that none of the devices have ever failed in flight due to Wi-Fi interference.

"The only know occurrence was during a developmental test conducted on the ground," it said, adding that, working with Boeing, it has already come up with new display hardware.

NASA Operation Icebridge: new light on changing Greenland ice

This is the calving front of Greenland's Jakobshavn Glacier seen during an IceBridge survey flight in 2012. 

Credit: NASA / Jefferson Beck

Research using NASA data is giving new insight into one of the processes causing Greenland's ice sheet to lose mass.

A team of scientists used satellite observations and ice thickness measurements gathered by NASA's Operation IceBridge to calculate the rate at which ice flows through Greenland's glaciers into the ocean.

The findings of this research give a clearer picture of how glacier flow affects the Greenland Ice Sheet and shows that this dynamic process is dominated by a small number of glaciers.

Over the past few years, Operation IceBridge measured the thickness of many of Greenland's glaciers, which allowed researchers to make a more accurate calculation of ice discharge rates.

In a new study published in the journal Geophysical Research Letters, researchers calculated ice discharge rates for 178 Greenland glaciers more than one kilometer (0.62 miles) wide.

Ice sheets grow when snow accumulates and is compacted into ice. They lose mass when ice and snow at the surface melts and runs off and when glaciers at the coast discharge ice into the ocean.

The difference between yearly snowfall on an ice sheet and the sum of melting and discharge is called a mass budget.

When these factors are equal, the mass budget is balanced, but for years the Greenland Ice Sheet has had a negative mass budget, meaning the ice sheet is losing mass overall.

For years the processes of surface melt and glacier discharge were roughly equal in size, but around 2006 surface melt increased and now exceeds iceberg production.

In recent years, computer model projections have shown an increasing dominance of surface melt, but a limited amount of glacier thickness data made pinpointing a figure for ice discharge difficult.

Ice discharge is controlled by three major factors: ice thickness, glacier valley shape and ice velocity.

MCoRDS

Researchers used data from IceBridge's ice-penetrating radar – the Multichannel Coherent Radar Depth Sounder, (MCoRDS), which is operated by the Center for Remote Sensing of Ice Sheets at the University of Kansas, Lawrence, Kan. – to determine ice thickness and sub-glacial terrain, and images from satellite sources such as Landsat and Terra to calculate velocity.

The team used several years of observations to ensure accuracy.

"Glacier discharge may vary considerably between years," said Ellyn Enderlin, glaciologist at the University of Maine, Orono, Maine and the study's lead author.

"Annual changes in speed and thickness must be taken into account."

Sustainability: How Wolves Change Rivers - Video

Visit Sustainableman.org/ to explore the world of sustainability.

For more from George Monbiot, visit monbiot.com and for more on "rewilding" and/or check out George Monbiot's book Feral: rewilding the land, the sea and human life.

NOTE: The "deer" the narrator refers to are in fact "elk," one of the largest of the deer family. The scientific report that this video is based on refers to elk so we wanted to be accurate with the truth of the story.

"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." - John Muir (English naturalist)

When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable "trophic cascade" occurred.

What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains in this movie remix.

Narration from TED: "For more wonder, rewild the world" by George Monbiot.

NASA MODIS: Temperature Feedback magnifying climate warming in Arctic

Mosaic of images of the Arctic by MODIS. Credit: NASA

A team of researchers with the Max Planck Institute in Germany, has found that temperature feedback in the Arctic is causing more warming in that region than sea ice albedo feedback.

In their paper published in the journal Nature Geoscience, the team describes how plugging data into a computer simulation revealed a "layered cake" atmosphere that traps heat over the polar cap.

Scientists have known for several years that temperatures in the Arctic are rising faster (due to global warming) than for the rest of the planet—for the most part, most climatologists have attributed this to sea ice albedo—a feedback system where a small rise in temperature leads to melting of ice and snow.

Less ice and snow means less heat is reflected back into space, which means more warming occurs, and so on. In this new effort, the researchers suggest that while sea ice albedo is causing temperatures to rise, it's second to temperature feedback in overall impact.

To gain a better perspective on why Arctic temperatures are increasing so much, the researchers turned to highly sophisticated and data intensive climate computer models.

Their model showed a cap of cold layered air hovering over the Arctic, holding in the heat. The researchers believe their simulation accurately portrays what actually exists in the real Arctic.

Normally, they explain, changing weather patterns (such as thunderstorms) in other parts of the world keep atmospheric air churning, which in turn allows heat closer to the ground to be moved higher, allowing some of it to escape into space.

Things are very different in the Arctic—there is very little churning, which means that warm air close to ground (just one to two kilometers thick) remains where it is, trapped by a heavy layered atmosphere.

The simulation also helps to explain why Arctic warming is more pronounced in the winter than during other seasons—even less mixing of the air in the atmosphere occurs because the air is so cold.

The team reports that their simulations show that the temperature feedback that occurs in the Arctic is causing more average temperature increase than sea ice albedo, the second most critical factor in causing warming.

They have not used their findings to try to predict what sort of overall impact increasing Arctic temperatures might have on the rest of the planet, however, if the polar cap will melt completely, or if it does, when it might occur.

More information: Arctic amplification dominated by temperature feedbacks in contemporary climate models, Nature Geoscience (2014) DOI: 10.1038/ngeo2071

ESA ERS-2 satellite: Arctic lakes show climate on thin ice

Floating ice (light blue) and grounded ice (dark blue) in lakes of Alaska’s North Slope near Barrow, as seen by ESA’s ERS-2 satellite in 2011. 

Credit: Planetary Visions / University of Waterloo, Canada / ESA

Ice in northern Alaska's lakes during winter months is on the decline.

Twenty years of satellite radar imagery show how changes in our climate are affecting high-latitude environments.

Changes in air temperature and winter precipitation over the last five decades have affected the timing, duration and thickness of the ice cover on lakes in the Arctic.

In this region, warmer climate conditions result in thinner ice cover on shallow lakes and, consequently, a smaller fraction of lakes freezing all the way through during winter months.

The Alaskan Arctic coastal plain is covered in a great swathe of shallow lakes 

Credit: NASA USGS

These changes in ice cover affect the local and regional climate, the dynamics of the underlying permafrost and the availability of water for residential and industrial use throughout the winter.

They also alter the physical, thermal and chemical properties of the water, affecting the ecology dependent on them.

But the magnitude of these changes had not yet been comprehensively documented until now.

In a recent study of Alaska's North Slope, published in The Cryosphere, the ice regimes of shallow lakes were documented using radar images from ESA's ERS-1 and -2 satellites.

The study reveals a 22% decrease of 'grounded ice' – or ice frozen through to the lakebed – from 1991 to 2011. This is equivalent to an overall thinning of ice by 21–38 cm.

Cristina Surdu

"Prior to starting our analysis, we were expecting to find a decline in ice thickness and grounded ice based on our examination of temperature and precipitation records of the past five decades from the Barrow meteorological station," said Cristina Surdu, lead author of the study.

"At the end of the analysis, when looking at trend analysis results, we were stunned to observe such a dramatic ice decline during a period of only 20 years."

The greatest change was observed during late winter (April–May) over the 20-year period, which gradually decreased from 1991 to 2005.

The ice experienced a more abrupt decline during the final six years of the analysis, reaching its lowest in 2011.

ERS-2 was launched in 1995, four years after ERS-1, the first European Remote Sensing satellite. 

At the time, these two satellites were the most sophisticated European Earth observation spacecraft ever developed, delivering new information to study Earth's land, oceans, atmosphere and polar ice, as well as being called upon to monitor natural disasters such as earthquakes and floods. 

Credit: EADS Astrium

ISS Crew Change: Soyuz reaches International Space Station in under six hours

A Russian Soyuz spacecraft carrying three new Expedition 37 crew members is seen approaching the International Space Station on Sept. 25, 2013. 

The Soyuz ferried American astronaut Mike Hopkins and Russian cosmonauts Oleg Kotov and Sergey Ryazanskiy to the space station.

A Soyuz spacecraft carrying an American astronaut and two Russian cosmonauts linked up with the International Space Station late Wednesday (Sept. 25), doubling the orbiting lab's crew size after an express trip to orbit.

A Soyuz capsule carrying two Russian cosmonauts and a NASA astronaut arrived at the station at 10:45 p.m. EDT (0245 GMT Thursday), less than six hours after launching into space from Baikonur Cosmodrome in the Central Asian nation of Kazakhstan.

The two spacecraft were sailing 261 miles (420 kilometers) over the southern Pacific Ocean, just off the coast of Peru, during their rendezvous.

The hatches between the two spacecraft are slated to open at 12:25 a.m. (0425 GMT) Thursday, at which point cosmonauts Oleg Kotov and Sergey Ryazanskiy and NASA's Michael Hopkins can join the three crew members of the current Expedition 37 already aboard the $100 billion orbiting lab.

Geoscientists predict new compounds change our view of what planets are made of

Structures of the newly predicted magnesium oxides: On the left, MgO2; on the right, Mg3O2. Green – Mg atoms, red – O atoms. Isosurfaces show regions of high electron localization.

A team of researchers led by Artem R. Oganov, a professor of theoretical crystallography in the Department of Geosciences, Stony Brook University, has made a startling prediction that challenges existing chemical models and current understanding of planetary interiors—magnesium oxide, a major material in the formation of planets, can exist in several different compositions.

Artem R. Oganov

The team's findings, "Novel stable compounds in the Mg-O system under high pressure," are published in the online edition of Physical Chemistry Chemical Physics.

The existence of these compounds—which are radically different from traditionally known or expected materials—could have important implications.

"For decades it was believed that MgO is the only thermo-dynamically stable magnesium oxide, and it was widely believed to be one of the main materials of the interiors of the Earth and other planets," said Qiang Zhu, the lead author of this paper and a postdoctoral student in the Oganov laboratory.

"We have predicted that two new compounds, MgO2 and Mg3O2, become stable at pressures above one and five million atmospheres, respectively. This not only overturns standard chemical intuition but also implies that planets may be made of totally unexpected materials. We have predicted conditions (pressure, temperature, oxygen fugacity) necessary for stability of these new materials, and some planets, though probably not the Earth, may offer such conditions," added Oganov.

In addition to their general chemical interest, MgO2 and Mg3O2 might be important planet-forming minerals in deep interiors of some planets. Planets with these compounds would most likely be the size of Earth or larger.

Qiang Zhu

The team explained how its paper predicted the structures in detail by analysing the electronic structure and chemical bonding for these compounds. For example, Mg3O2 is forbidden within "textbook chemistry," where the Mg ions can only have charges "+2," O ions are "-2, and the only allowed compound is MgO.

In the "oxygen-deficient" semiconductor Mg3O2, there are strong electronic concentrations in the "empty space" of the structure that play the role of negatively charged ions and stabilize this material.

Curiously, magnesium becomes a d-element (i.e. a transition metal) under pressure, and this almost alchemical transformation is responsible for the existence of the "forbidden" compound Mg3O2.

The findings were made using unique methods of structure prediction, developed in the Oganov laboratory.

"These methods have led to the discovery of many new phenomena and are used by a number of companies for systematically discovering novel materials on the computer—a much cheaper route, compared to traditional experimental methods," said Zhu.

"It is known that MgO makes up about 10 percent of the volume of our planet, and on other planets this fraction can be larger. The road is now open for a systematic discovery of new unexpected planet-forming materials," concluded Oganov.

More information: 
Zhu Q., Oganov A.R., Lyakhov A.O. (2013). Novel stable compounds in the Mg-O system under high pressure. Phys. Chem. Chem. Phys., in press. pubs.rsc.org/en/content/articlelanding/2013/cp/c3cp50678a

Kilauea: Tiny Gravity Changes Show Magma's Underground Movements

Kilauea's current eruption is still going strong after 29 years.

CREDIT: USGS/HVO.

The secret movements of magma deep inside a volcano can be detected by tracking the subtle changes in gravity they cause.

Surprising readings from a Hawaiian volcano have researchers hoping to better understand volcanic activity through gravity monitoring.

Continuous gravity measurements of active volcanoes are relatively rare, with most results coming from Mount Etna in Italy.

"One problem is the expense," researcher Michael Poland, a geophysicist at the U.S. Geological Survey's Hawaiian Volcano Observatory, explained.

"Gravity measurements have always been a really expensive endeavor. The big users are oil and mining companies."

Now scientists have monitored the gravity at Kīlauea, a popular tourist destination on Hawaii's Big Island, and discovered a regular cycle of fluctuations that suggest magma is churning a kilometer (0.6 miles) below the surface.

The way magma churns in underground chambers below volcanic vents is key to understanding how persistent volcanoes are, and whether or not they might catastrophically erupt in the future.

However, what goes on deep under the Earth's surface is difficult to monitor.

One way to peer underground is by looking at Earth's gravity, the researchers said. Anything that has mass has a gravity field that pulls objects toward it.

The strength of this field depends on the amount of mass. Since the Earth's mass is not spread out evenly, this means the strength of the planet's gravitational pull is stronger in some places and weaker in others.

As such, the flow of magma from one place to another can be detected from above.

Most active volcano

"Kīlauea is the world's most active volcano," Poland said. "It's erupted almost continuously since 1983. It's a natural 'lab volcano' ―a great place to try and study something like gravity measurements."

The researchers installed two continuous gravity meters at the summit of the volcano in 2010. One was about 1.2 miles (2 kilometers) northwest of the eruptive vent at the summit and recorded measurements every10 seconds, while the other was placed about 500 feet (150 meters) east and recorded data every second.

They detected gravity fluctuations that came in a cycle about 150 seconds long.

"There was no expectation for that kind of result," Poland reported. "That gravity oscillation came out of nowhere. It points to the idea that there's probably a lot of things going on in volcanoes, glaciers, wherever you look, but we haven't developed the tools to detect these sorts of things."

NASA CNES Jason 1 Satellite: Returning to Service May 4 in Lower Orbit

The U.S.-French Jason-1 ocean-altimetry satellite, which was put into a safe-hold mode on March 3 after an on-board failure, is expected to return to service May 4 from a lower orbit, program managers said April 26.

The new orbit of 1,323.4 kilometers in altitude — some 12.6 kilometers lower than the former position — will permit ground controllers to operate Jason-1 until it fails completely, as this altitude is considered low enough to serve as a graveyard orbit, officials said.

The lower position means Jason-1 will not clutter the more-useful operational orbit in the event it fails without warning. It also reduces the number of years it will take before atmospheric drag pulls it into a destructive re-entry once it is retired.

Jason-1 was launched in December 2001 on what was supposed to be a three-year mission to succeed the larger U.S.-French Topex-Poseidon satellite.

Ocean altimetry’s popularity with civil and military customers has only grown since then.

Jason-2 was launched in August 2008, and has been operated in tandem with Jason-1 to increase the frequency of altimetry data returned to users. Jason-3 is scheduled for launch in 2014 and a successor satellite to that is being designed by the 19-nation European Space Agency.

The U.S.-French Jason operating team said Jason-1, whose payload instruments were switched on starting April 24 after a seven-week outage, should be able to perform partial service for at least another year.

“The move from the altimetry reference orbit has been a difficult decision to take, but it also signals the start of an exciting new chapter in the extraordinary mission of Jason-1,” the Jason-1 team from the NASA Jet Propulsion Laboratory and the French space agency, CNES, said in an April 23 message to users.

Venice: Curly Pasta shaped Radiowaves to solve congestion

A group of Italian and Swedish researchers appears to have solved the problem of radio congestion by cleverly twisting radio waves into the shape of fusilli pasta, allowing a potentially infinite number of channels to be broadcast and received.

the researchers have demonstrated this in real-life conditions by beaming two twisted radio waves across the waters of Venice.

Their results have been reported today, Friday 2 March, in the Institute of Physics and German Physical Society's New Journal of Physics and are accompanied by a video abstract that gives an excellent insight into the authors' work.

As the world continues to adapt in the digital age, the introduction of new mobile smartphones, wireless internet and digital TVs means the number of radio frequency bands available to broadcast information gets smaller and smaller.

"You just have to try sending a text message at midnight on New Year's Eve to realise how congested the bands are," said lead author Dr Fabrizio Tamburini.

The researchers, from the University of Padova, Italy, and the Angstrom Laboratory, Sweden, devised a solution to this by manipulating waves so that they can hold more than one channel of information.

In addition to increasing the quantity of information being passed around our planet, this new discovery could also help lend an insight into objects far out in our galaxy. Black holes, for example, are constantly rotating and as waves pass them, they are forced to twist in line with the black hole.

According to Tamburini, analysing the incoming waves from the supermassive black hole at the centre of the Milky Way, Sagittarius A, could help astronomers obtain crucial information about the rotation of this "million-solar mass monster."

More information: "Encoding many channels on the same frequency through radio vorticity: first experimental test" Tamburini F et al 2012 New J. Phys. 14 033001 - http://iopscience. … 3001/article

Minority rules: Scientists discover tipping point for ideas

In this visualisation, we see the tipping point where minority opinion (shown in red) quickly becomes majority opinion. Over time, the minority opinion grows.

Once the minority opinion reached 10 percent of the population, the network quickly changes as the minority opinion takes over the original majority opinion (shown in green).

Credit: SCNARC/Rensselaer Polytechnic Institute

NASA MARS Recon Orbiter: Big Changes in Mars' Atmosphere

NASA's Mars Reconnaissance Orbiter has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet's axis varies.

This process can affect the stability of liquid water, if it exists on the Martian surface, and increase the frequency and severity of Martian dust storms.

Researchers using the orbiter's ground-penetrating radar identified a large, buried deposit of frozen carbon dioxide, or dry ice, at the Red Planet's south pole.

The scientists suspect that much of this carbon dioxide enters the planet's atmosphere and swells the atmosphere's mass when Mars' tilt increases. The findings are published in this week's issue of the journal Science.

The newly found deposit has a volume similar to Lake Superior's nearly 3,000 cubic miles (about 12,000 cubic kilometers). The deposit holds up to 80 percent as much carbon dioxide as today's Martian atmosphere.

Collapse pits caused by dry ice sublimation and other clues suggest the deposit is in a dissipating phase, adding gas to the atmosphere each year. Mars' atmosphere is about 95 percent carbon dioxide, in contrast to Earth's much thicker atmosphere, which is less than .04 percent carbon dioxide.

"We already knew there is a small perennial cap of carbon-dioxide ice on top of the water ice there, but this buried deposit has about 30 times more dry ice than previously estimated," said Roger Phillips of Southwest Research Institute in Boulder, Colo. Phillips is deputy team leader for the Mars Reconnaissance Orbiter's Shallow Radar instrument and lead author of the report.

"We identified the deposit as dry ice by determining the radar signature fit the radio-wave transmission characteristics of frozen carbon dioxide far better than the characteristics of frozen water," said Roberto Seu of Sapienza University of Rome, team leader for the Shallow Radar and a co-author of the new report. Additional evidence came from correlating the deposit to visible sublimation features typical of dry ice.

"When you include this buried deposit, Martian carbon dioxide right now is roughly half frozen and half in the atmosphere, but at other times it can be nearly all frozen or nearly all in the atmosphere," Phillips said.

An occasional increase in the atmosphere would strengthen winds, lofting more dust and leading to more frequent and more intense dust storms. Another result is an expanded area on the planet's surface where liquid water could persist without boiling. Modeling based on known variation in the tilt of Mars' axis suggests several-fold changes in the total mass of the planet's atmosphere can happen on time frames of 100,000 years or less.

The changes in atmospheric density caused by the carbon-dioxide increase also would amplify some effects of the changes caused by the tilt.

Researchers plugged the mass of the buried carbon-dioxide deposit into climate models for the period when Mars' tilt and orbital properties maximize the amount of summer sunshine hitting the south pole. They found at such times, global, year-round average air pressure is approximately 75 percent greater than the current level.

"A tilted Mars with a thicker carbon-dioxide atmosphere causes a greenhouse effect that tries to warm the Martian surface, while thicker and longer-lived polar ice caps try to cool it," said co-author Robert Haberle, a planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "Our simulations show the polar caps cool more than the greenhouse warms.

Earth's Seasonal Change: Not-So-Equal Equinox

The seasons on Earth will officially change Wednesday, heralding their shifting nature with an astronomical feat: the autumnal equinox.


On Sept. 22, at 11:09 p.m. EDT (8:09 p.m. PDT), the fall season will begin in the Northern Hemisphere while the Earth's Southern Hemisphere residents ring in their spring. This date – one of two each year – is called an equinox, from the Latin for "equal night," alluding to the fact that day and night are then of equal length worldwide but this is not necessarily so.

The not-so-equal equinox


The definition of the equinox as being a time of equal day and night is a convenient oversimplification.


For one thing, it treats night as simply the time the sun is beneath the horizon, and completely ignores twilight. If the sun were nothing more than a point of light in the sky and if Earth lacked an atmosphere, then at the time of an equinox the sun would indeed spend one half of its path above the horizon and one half below.


But in reality, atmospheric refraction raises the sun's disk by more than its own apparent diameter while it is rising or setting. Thus, when we see the sun as a reddish-orange ball just sitting on the horizon, we're looking at an optical illusion. [Top 10 Extreme Planet Facts]


It is actually completely below the horizon. So from our point of view, the day on an equinox appears longer than it actually is. This illusion means that the appearance of equal day and night, from a skywatcher's view, will come several days later.


In addition to refraction hastening sunrise and delaying sunset, there is another factor that makes daylight longer than night at an equinox: Sunrise and sunset are defined as the times when the first or last speck of the sun's upper limb is visible above the horizon – not the center of the disk.


This is why, when you check your newspaper's almanac or weather page on Wednesday of this week to look up the times of local sunrise and sunset, you'll notice that the duration of daylight from sunrise to sunset still lasts a bit more than 12 hours – not exactly 12 as the term "equinox" suggests.

Arctic Expedition Investigates Climate Change and Alternative Fuels

Scientists from the Marine Biogeochemistry and Geology and Geophysics sections of the Naval Research Laboratory (NRL) organized and led a team of university and government scientists on an Arctic expedition to initiate methane hydrate exploration in the Beaufort Sea and determine the spatial variation of sediment contribution to Arctic climate change.

Utilising the U.S. Coast Guard Cutter Polar Sea as a research platform, three cross-shelf transects were surveyed and sampled off Alaska's North Slope at Hammerhead, Thetis Island and Halkett representing three regions of the Alaskan shelf.

The expedition integrated expertise in coastal geophysics, sediment geochemistry, dissolved and free methane fluxes through the water column and into the atmosphere, sediment and water column microbiology and biogeochemistry and detailed characterization of the sub-seafloor geology.

"The objective of the sampling is to help determine variations in the shallow sediment and water column methane sources, methane cycling and the subsequent flux to the atmosphere," said Richard Coffin, chief scientist, NRL Chemistry Division.

The content, location and distribution of methane in hydrate is variable and controlled by geothermal gradients and biological and thermal methane production. Large deposits of methane hydrates, frozen mixtures of hydrocarbon gas (mostly methane) and water, occur over large areas of the ocean floor. International research has begun with a primary goal of obtaining the methane in these hydrates as an energy source.

During the 12-day expedition, Methane In The Arctic Shelf and Slope (MITAS-1), the crew conducted 34 conductivity-temperature-depth (CTD) water column casts using a rosette of Niskin bottles and collected sediment samples from 14 piston cores, three vibrocores and 20 multicores.

Regions selected for this study were based on the review of Minerals Management Service and U.S. Geologic Survey (USGS) seismic data with specific sample locations decided onboard through review of the 3.5 Kilohertz (kHz) sub-bottom profiler data.

The MITAS-1 crew focused on six primary goals to include:

+ Acquire and integrate seismic, acoustic, temperature, geochemical, and lithostratigraphic data for evaluation of deep sediment hydrate distributions.

+ Estimate spatial variation and controls on the vertical methane flux as it relates to variations in lithostratigraphy, geologic structures, water column temperatures, heat flow, seismic and acoustic profiles, and water depth.

+ Develop and calibrate models to evaluate sediment hydrate loading, hydrate destabilization through warming, and the fate of methane after destabilization.

+ Determine and model the transport of methane from the sediment through the water column into the atmosphere.

+ Study the control of total methane emissions by microbial methane consumption in the sediment and in the water column.

+ Study the contribution of methane to the benthic and pelagic carbon cycling.

The expedition was supported by NRL, Office of Naval Research (ONR), Department of Energy (DoE), Royal Netherlands Institute for Sea Research (NIOZ), French Research Institute for Exploitation of the Sea (IFREMER) and the German Leibniz Institute of Marine Sciences (IFM-Geomar). Future expeditions will also include scientists from Scotland's Herriot-Watt University, Norway's University of Bergen and GNS Science of New Zealand.

"Our project is intended to initiate a long-term collaboration in future expeditions in the Beaufort Sea and other regions of the Arctic Ocean," said Coffin.

Humanity Must Save the Wild Tigers: An Obligation without Negotiation

There are only 3000 Tigers left in the wild. There are only 3000 Tigers left in the wild. Sorry, but it needs repeating. Wild Tigers have never been in a tighter spot and only humanity can help.

Only 1.7 per cent of historical tiger numbers are alive today. Indian tigers, such as the one seen here charging the camera, could be a new focus of conservation.

New research in PLoS Genetics suggests that the most effective way to save the wild tiger or at least a representative group, is to focus conservation efforts on the Indian variety, which has over half of the species's genetic diversity. By default, this also means turning our backs on 50% of Tiger genes that we deem as 'un-saveable' or beyond 'salvation'. It brings great shame on humanity to admit this and endorse it.

Indian tigers are equipped with such eclectic genes, that it could be better able to adapt to the future change, inflicted on it by humanity, than any other tiger on Earth.

Why are we continuing to stress this species to extinction. Is it purely economics and money or is it simply a selfish drive to become, not only the dominant species on the Earth but the only species.

Climate Change - Geoengineering