End Of The Earth

Sun Unleashes X-class Flare

2014-01-08T21:50:00.001-08:00

A giant cloud of solar particles, called a coronal mass ejection, explodes off the sun on Jan. 7, 2014, as seen in the light halo to the lower right in this image captured by ESA/NASA's Solar and Heliospheric Observatory. The sun is obscured to better see the tenuous atmosphere around it.

The Jan. 7, 2014, X-class flare was also associated with a coronal mass ejection, or CME, another solar phenomenon that can send billions of tons of particles into space that can reach Earth one to three days later. These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.
The European Space Agency and NASA's Solar and Heliospheric Observatory, or SOHO, captured an image of the giant particle cloud as it burst away from the sun.
To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
Updates will be provided as needed.
The sun emitted a significant solar flare peaking at 1:32 p.m. EST on Jan.7, 2014. This is the first significant flare of 2014, and follows on the heels of mid-level flare earlier in the day. Each flare was centered over a different area of a large sunspot group currently situated at the center of the sun, about half way through its 14-day journey across the front of the disk along with the rotation of the sun.
Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.
To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
This flare is classified as an X1.2-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.
Updates will be provided as needed.

This labeled image taken by SDO's Helioseismic and Magnetic Imager shows the location of two active regions on the sun, labeled AR1944 and AR1943, which straddle a giant sunspot complex. A Jan. 17, 2014, X1.2-class flare emanated from an area closer to AR1943.

This pictures combines two images from NASA's Solar Dynamics Observatory captured on Jan. 7, 2013. Together, the images show the location of a giant sunspot group on the sun, and the position of an X-class flare that erupted at 1:32 p.m. EST.

New Results From Inside the Ozone Hole

2014-01-08T21:37:00.002-08:00

NASA scientists have revealed the inner workings of the ozone hole that forms annually over Antarctica and found that declining chlorine in the stratosphere has not yet caused a recovery of the ozone hole.
More than 20 years after the Montreal Protocol agreement limited human emissions of ozone-depleting substances, satellites have monitored the area of the annual ozone hole and watched it essentially stabilize, ceasing to grow substantially larger. However, two new studies show that signs of recovery are not yet present, and that temperature and winds are still driving any annual changes in ozone hole size.
"Ozone holes with smaller areas and a larger total amount of ozone are not necessarily evidence of recovery attributable to the expected chlorine decline," said Susan Strahan of NASA's Goddard Space Flight Center in Greenbelt, Md. "That assumption is like trying to understand what's wrong with your car's engine without lifting the hood."
To find out what's been happening under the ozone hole's hood, Strahan and Natalya Kramarova, also of NASA Goddard, used satellite data to peer inside the hole. The research was presented Wednesday at the annual meeting of the American Geophysical Union in San Francisco.
Kramarova tackled the 2012 ozone hole, the second-smallest hole since the mid 1980s. To find out what caused the hole's diminutive area, she turned to data from the NASA-NOAA Suomi National Polar-orbiting Partnership satellite, and gained the first look inside the hole with the satellite's Ozone Mapper and Profiler Suite's Limb Profiler. Next, data were converted into a map that shows how the amount of ozone differed with altitude throughout the stratosphere in the center of the hole during the 2012 season, from September through November.
The map revealed that the 2012 ozone hole was more complex than previously thought. Increases of ozone at upper altitudes in early October, carried there by winds, occurred above the ozone destruction in the lower stratosphere.
"Our work shows that the classic metrics based on the total ozone values have limitations – they don't tell us the whole story," Kramarova said.

(A look inside the 2012 ozone hole with the Ozone Mapper and Profiler Suite shows how the build-up of ozone (parts per million by volume) in the middle stratosphere masks the ozone loss in the lower stratosphere.)

The classic metrics create the impression that the ozone hole has improved as a result of the Montreal protocol. In reality, meteorology was responsible for the increased ozone and resulting smaller hole, as ozone-depleting substances that year were still elevated. The study has been submitted to the journal of Atmospheric Chemistry and Physics.
Separate research led by Strahan tackled the holes of 2006 and 2011 – two of the largest and deepest holes in the past decade. Despite their similar area, however, Strahan shows that they became that way for very different reasons.
Strahan used data from the NASA Aura satellite's Microwave Limb Sounder to track the amount of nitrous oxide, a tracer gas inversely related to the amount of ozone depleting chlorine. The researchers were surprised to find that the holes of 2006 and 2011 contained different amounts of ozone-depleting chlorine. Given that fact, how could the two holes be equally severe?
The researchers next used a model to simulate the chemistry and winds of the atmosphere. Then they re-ran the simulation with the ozone-destroying reactions turned off to understand the role that the winds played in bringing ozone to the Antarctic. Results showed that in 2011, there was less ozone destruction than in 2006 because the winds transported less ozone to the Antarctic – so there was less ozone to lose. This was a meteorological, not chemical effect. In contrast, wind blew more ozone to the Antarctic in 2006 and thus there was more ozone destruction. The research has been submitted to the journal Geophysical Research Letters.
This work shows that the severity of the ozone hole as measured by the classic total column measurements does not reveal the significant year-to-year variations in the two factors that control ozone: the winds that bring ozone to the Antarctic and the chemical loss due to chlorine.
Until chlorine levels in the lower stratosphere decline below the early 1990s level – expected sometime after 2015 but likely by 2030 – temperature and winds will continue to dictate the variable area of the hole in any given year. Not until after the mid 2030s will the decline stratospheric chlorine be the primary factor in the decline of ozone hole area.

"We are still in the period where small changes in chlorine do not affect the area of the ozone hole, which is why it's too soon to say the ozone hole is recovering," Strahan said. "We're going into a period of large variability and there will be bumps in the road before we can identify a clear recovery."

Two Solar Flares Say Goodbye 2013 and Welcome 2014

2014-01-04T04:31:00.004-08:00

Two Solar Flares Say Goodbye 2013 and Welcome 2014

Several wavelengths of light are combined in this New Year's Day solar flare image, categorized as an M9.9 and peaking at 1:52 p.m. EST on Jan. 1, 2014. Each wavelength represents material at a different temperatures, helping scientists understand how it is moved and heated through these events

The sun ushered out 2013 and welcomed 2014 with two mid-level flares on Dec. 31, 2013 and Jan. 1, 2014. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.
To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
The first flare (below) was categorized as an M6.4 and it peaked at 4:58 p.m EST on Dec. 31. The second (above) was categorized as an M9.9 and peaked at 1:52 p.m. EST on Jan. 1. Both flares emerged from the same active region on the sun, AR1936.
Imagery of the flares was captured by NASA's Solar Dynamics Observatory, which keeps a constant watch on the sun, collecting new data every 12 seconds.

An M6.4 class solar flare erupts from the sun in this image from NASA's Solar Dynamics Observatory, which was captured on Dec. 31, at 4:59 p.m. EST. The image shows light in the 304 Angstrom wavelength, which is typically colorized in red.

Communications Tests Go the Distance for MAVEN

2013-09-21T07:17:00.001-07:00

Communications Tests Go the Distance for MAVEN

Engineers work on the MAVEN spacecraft, which is dominated by the high-gain antenna that is crucial to communications with NASA's Deep Space Network.

By Steven Siceloff,
Kennedy Space Center
It's not easy to simulate millions of miles electronically, but that's what engineers did recently as they tested the all-important communications system the MAVEN spacecraft will use to relay its study results from Mars orbit to Earth-bound researchers.

One of the antennas at the Canberra, Australia, station of NASA's Deep Space Network used to communicate with spacecraft operating far from Earth.

Working from their consoles at NASA's Kennedy Space Center, a team of test engineers from the Jet Propulsion Laboratory in California, better known as JPL, conducted more than a week of evaluations on the antennas and circuitry aboard the spacecraft.
They beamed signals to the low-gain and high-gain antennas on MAVEN and basically treated the machine as though it really were flying on a 10-month journey from Earth to Mars and then studying the upper atmosphere of the Red Planet.
Such work is critical, mission managers said, because there is no way to fix a spacecraft's communications system once it leaves Earth.
"It doesn't matter what we do out there if we can't get the data back to Earth," said Jeff Coyne, Lockheed Martin's Assembly Test and Launch Operations manager for the project.
MAVEN is short for Mars Atmosphere and Volatile Evolution. It is scheduled to launch in November aboard a United Launch Alliance Atlas V.
"I say this is one of the most important things, because if we can't talk to it . . . ," said Sheryl Bergstrom, manager of JPL's Cape Operations Office at Kennedy.
The testing was standard stuff for the engineers, but nonetheless mind-bending considering that the spacecraft will operate millions of miles from Earth and rely on commands from operators at Goddard Space Flight Center in Maryland.
To mimic the distances between the spacecraft and Earth, the electronic signals sent between the two during testing are run through a cabling system that quickly ramps down the power by going through various wiring networks.
"We'll try to squeeze the signal down to its lowest possible point," said Chris Green, an engineer with Exelis who supervised the testing. "It's a machine and we test its actual flight performance -- every scenario of flight configuration it would be in is what we go through in testing."
"We allow the project to get online and do what they would do on a normal day so they can perform all the tasks through us just as if MAVEN was actually in space," said Lorenzo Morgan, one of the engineers operating and evaluating the procedures.
Although every spacecraft goes through intense communications testing, the work is not considered routine because every spacecraft has unique requirements.
"Every mission is different, every mission has its own peculiarities," said Albert Ibarra, also a test engineer for the communications system. "You have to know the details on every spacecraft design and so you become familiar with it as soon as they start putting the spacecraft together."
NASA has an intricate system of antennas in California, Spain and Australia to pick up and transmit signals to its fleet of spacecraft that now reaches out beyond the solar system in the form of Voyager 1.
Called the Deep Space Network and referred to by its acronym, DSN, the system uses antennas almost as big as a football field to communicate with the spacecraft that are using their own much smaller antennas and more limited power sources.
It's the system NASA uses to communicate with all of its interplanetary probes and some of the spacecraft studying Earth, as well. In addition to Voyager 1, whose signal is incredibly weak because of the vast distance it is from Earth, the network is picking up signals from newer spacecraft such as New Horizons, which is speeding toward Pluto. Cassini in orbit around Saturn, Juno on its way to Jupiter and the Curiosity rover operating on Mars all relay their data to Earth on the DSN and get their commands from ground operators through the same network.
Kennedy's portion of the DSN structure is a testing facility called MIL-71, a reference to the time when the space center was known as the Merritt Island Launch Annex. Every time a spacecraft comes to Kennedy for launch preparations, a team of engineers sets up racks of equipment and computer servers before beginning several days of 12-hour shifts to make sure the mission's communications system and interface with the Deep Space Network will work.
With the spacecraft checked out, the team takes its gear back to California and gets ready for launch day, knowing very well that it won't hear anything from the spacecraft until well after liftoff. In the case of MAVEN, the engineers and scientists won't find out if the testing really was successful until 54 minutes after launch from Cape Canaveral when MAVEN makes its initial contact with the DSN.
"When the signal is acquired," said Bergstrom, a veteran of long wait-times for good missions and bad, "that's when we get to breathe."

How Do We Know When Voyager Reaches Interstellar Space?

2013-09-15T20:55:00.000-07:00

Voyager Reaches Interstellar Space

You Are Here, Voyager: This artist's concept puts huge solar system distances in perspective. The scale bar is measured in astronomical units (AU), with each set distance beyond 1 AU representing 10 times the previous distance. Each AU is equal to the distance from the sun to the Earth. It took from 1977 to 2013 for Voyager 1 to reach the edge of interstellar space

Whether and when NASA's Voyager 1 spacecraft, humankind's most distant object, broke through to interstellar space, the space between stars, has been a thorny issue. For the last year, claims have surfaced every few months that Voyager 1 has "left our solar system." Why has the Voyager team held off from saying the craft reached interstellar space until now?

"We have been cautious because we're dealing with one of the most important milestones in the history of exploration,” said Voyager Project Scientist Ed Stone of the California Institute of Technology in Pasadena. “Only now do we have the data -- and the analysis -- we needed."
Basically, the team needed more data on plasma, which is ionized gas, the densest and slowest moving of charged particles in space. (The glow of neon in a storefront sign is an example of plasma.) Plasma is the most importantmarker that distinguishes whether Voyager 1 is inside the solar bubble, known as the heliosphere, which is inflated by plasma that streams outward from our sun, or in interstellar space and surrounded by material ejected by the explosion of nearby giant stars millions of years ago. Adding to the challenge: they didn't know how they'd be able to detect it. "We looked for the signs predicted by the models that use the best available data, but until now we had no measurements of the plasma from Voyager 1," said Stone.
Scientific debates can take years, even decades to settle, especially when more data are needed. It took decades, for instance, for scientists to understand the idea of plate tectonics, the theory that explains the shape of Earth's continents and the structure of its sea floors. First introduced in the 1910s, continental drift and related ideas were controversial for years. A mature theory of plate tectonics didn't emerge until the 1950s and 1960s. Only after scientists gathered data showing that sea floors slowly spread out from mid-ocean ridges did they finally start accepting the theory. Most active geophysicists accepted plate tectonics by the late 1960s, though some never did.
Voyager 1 is exploring an even more unfamiliar place than our Earth's sea floors -- a place more than 11 billion miles (17 billion kilometers) away from our sun. It has been sending back so much unexpected data that the science team has been grappling with the question of how to explain all the information. None of the handful of models the Voyager team uses as blueprints have accounted for the observations about the transition between our heliosphere and the interstellar medium in detail. The team has known it might take months, or longer, to understand the data fully and draw their conclusions.
"No one has been to interstellar space before, and it's like traveling with guidebooks that are incomplete," said Stone. "Still, uncertainty is part of exploration. We wouldn't go exploring if we knew exactly what we'd find."
The two Voyager spacecraft were launched in 1977 and, between them, had visited Jupiter, Saturn, Uranus and Neptune by 1989. Voyager 1's plasma instrument, which measures the density, temperature and speed of plasma, stopped working in 1980, right after its last planetary flyby. When Voyager 1 detected the pressure of interstellar space on our heliosphere in 2004, the science team didn't have the instrument that would provide the most direct measurements of plasma. Instead, they focused on the direction of the magnetic field as a proxy for source of the plasma. Since solar plasma carries the magnetic field lines emanating from the sun and interstellar plasma carries interstellar magnetic field lines, the directions of the solar and interstellar magnetic fields were expected to differ.
Most models told the Voyager science team to expect an abrupt change in the magnetic field direction as Voyager switched from the solar magnetic field lines inside our solar bubble to those in interstellar space. The models also said to expect the levels of charged particles originating from inside the heliosphere to drop and the levels of galactic cosmic rays, which originate outside the heliosphere, to jump.
In May 2012, the number of galactic cosmic rays made its first significant jump, while some of the inside particles made their first significant dip. The pace of change quickened dramatically on July 28, 2012. After five days, the intensities returned to what they had been. This was the first taste of a new region, and at the time Voyager scientists thought the spacecraft might have briefly touched the edge of interstellar space.
By Aug. 25, when, as we now know, Voyager 1 entered this new region for good, all the lower-energy particles from inside zipped away. Some inside particles dropped by more than a factor of 1,000 compared to 2004. The levels of galactic cosmic rays jumped to the highest of the entire mission. These would be the expected changes if Voyager 1 had crossed the heliopause, which is the boundary between the heliosphere and interstellar space. However, subsequent analysis of the magnetic field data revealed that even though the magnetic field strength jumped by 60 percent at the boundary, the direction changed less than 2 degrees. This suggested that Voyager 1 had not left the solar magnetic field and had only entered a new region, still inside our solar bubble, that had been depleted of inside particles.
Then, in April 2013, scientists got another piece of the puzzle by chance. For the first eight years of exploring the heliosheath, which is the outer layer of the heliosphere, Voyager's plasma wave instrument had heard nothing. But the plasma wave science team, led by Don Gurnett and Bill Kurth at the University of Iowa, Iowa City, had observed bursts of radio waves in 1983 to 1984 and again in 1992 to 1993. They deduced these bursts were produced by the interstellar plasma when a large outburst of solar material would plow into it and cause it to oscillate. It took about 400 days for such solar outbursts to reach interstellar space, leading to an estimated distance of 117 to 177 AU (117 to 177 times the distance from the sun to the Earth) to the heliopause. They knew, though, that they would be able to observe plasma oscillations directly once Voyager 1 was surrounded by interstellar plasma.
Then on April 9, 2013, it happened: Voyager 1's plasma wave instrument picked up local plasma oscillations. Scientists think they probably stemmed from a burst of solar activity from a year before, a burst that has become known as the St. Patrick's Day Solar Storms. The oscillations increased in pitch through May 22 and indicated that Voyager was moving into an increasingly dense region of plasma. This plasma had the signatures of interstellar plasma, with a density more than 40 times that observed by Voyager 2 in the heliosheath.
Gurnett and Kurth began going through the recent data and found a fainter, lower-frequency set of oscillations from Oct. 23 to Nov. 27, 2012. When they extrapolated back, they deduced that Voyager had first encountered this dense interstellar plasma in August 2012, consistent with the sharp boundaries in the charged particle and magnetic field data on August 25.
Stone called three meetings of the Voyager team. They had to decide how to define the boundary between our solar bubble and interstellar space and how to interpret all the data Voyager 1 had been sending back. There was general agreement Voyager 1 was seeing interstellar plasma, based on the results from Gurnett and Kurth, but the sun still had influence. One persisting sign of solar influence, for example, was the detection of outside particles hitting Voyager from some directions more than others. In interstellar space, these particles would be expected to hit Voyager uniformly from all directions.
"Now that we had actual measurements of the plasma environment – by way of an unexpected outburst from the sun – we had to reconsider why there was still solar influence on the magnetic field and plasma in interstellar space," Stone said.
"The path to interstellar space has been a lot more complicated than we imagined."
Stone discussed with the Voyager science group whether they thought Voyager 1 had crossed the heliopause. What should they call the region were Voyager 1 is?
"In the end, there was general agreement that Voyager 1 was indeed outside in interstellar space," Stone said. "But that location comes with some disclaimers – we're in a mixed, transitional region of interstellar space. We don't know when we'll reach interstellar space free from the influence of our solar bubble."
So, would the team say Voyager 1 has left the solar system? Not exactly – and that's part of the confusion. Since the 1960s, most scientists have defined our solar system as going out to the Oort Cloud, where the comets that swing by our sun on long timescales originate. That area is where the gravity of other stars begins to dominate that of the sun. It will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Informally, of course, "solar system" typically means the planetary neighborhood around our sun. Because of this ambiguity, the Voyager team has lately favored talking about interstellar space, which is specifically the space between each star's realm of plasma influence.
"What we can say is Voyager 1 is bathed in matter from other stars," Stone said. "What we can't say is what exact discoveries await Voyager's continued journey. No one was able to predict all of the details that Voyager 1 has seen. So we expect more surprises."
Voyager 1, which is working with a finite power supply, has enough electrical power to keep operating the fields and particles science instruments through at least 2020, which will mark 43 years of continual operation. At that point, mission managers will have to start turning off these instruments one by one to conserve power, with the last one turning off around 2025.
Voyager 1 will continue sending engineering data for a few more years after the last science instrument is turned off, but after that it will be sailing on as a silent ambassador. In about 40,000 years, it will be closer to the star AC +79 3888 than our own sun. (AC +79 3888 is traveling toward us faster than we are traveling towards it, so while Alpha Centauri is the next closest star now, it won't be in 40,000 years.) And for the rest of time, Voyager 1 will continue orbiting around the heart of the Milky Way galaxy, with our sun but a tiny point of light among many.
The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.
For more information about Voyager, visit: http://voyager.jpl.nasa.gov

Small Earthquakes May Cause Surprisingly Big Tsunamis

2012-05-18T19:52:00.001-07:00

Mysterious small tremors in the most earthquake-prone areas on Earth may be the cause of surprisingly large tsunamis, researchers say.

These findings might also shed light on the huge tsunami generated by the disastrous magnitude 9.0 quake that hit Japan in 2011.

Nearly all of the 10 largest recorded earthquakes on Earth happened along subduction zones, where one of the tectonic plates making up the planet's surface is diving beneath another. The shallow regions of these zones are often not seismically active by themselves, but occasionally strange tremors are recorded from these locales that are rich in very-low-frequency seismic waves.
These shallow areas also seem to be home to so-called tsunami earthquakes, which generate tsunamis far stronger than one would expect for the amount of seismic energy they release. The Keicho quake of 1605 that caused disastrous tsunamis in Japan and killed thousands might have been one such earthquake.
To see if there were any links between the very-low-frequency events and tsunami earthquakes seen in the shallows of subduction zones, scientists in Japan used three ocean-bottom seismometers to analyze a swarm of very-low-frequency events in 2009. These occurred in the shallowest parts of the Nankai Trough, a part of a subduction zone near southwestern Japan that is rocked by giant earthquakes every century or so — most recently in 1946, when a magnitude 8.2 event killed an estimated 1,300 people.

The researchers discovered that the very-low-frequency quakes — ranging from magnitudes of 3.8 to 4.9 — can last 30 to 100 seconds. This is unusually long when compared with the 1-to-2 second duration of ordinary earthquakes with comparable magnitudes.
Although these very-low-frequency quakes get their name from seismic waves detected on land, the researchers discovered these events are actually rich in high-frequency waves as well. High-frequency waves tend to weaken with distance as they go through matter, which is why land seismometers did not detect these waves but ocean seismometers closer to the quakes did. The long duration of the quakes and the high-frequency waves now seen from them suggest these events may be caused by fluid seeping into fractures in the rock, making it easier for parts of the earth to slip past each other and generate tsunami earthquakes.
These findings suggest that authorities should keep a closer eye on the shallow areas of subduction zones. For instance, the huge tsunamis generated by the magnitude 9.0 quake that struck Japan in 2011 might be due in significant part to a slip in the shallow parts of the Japan Trench lying east of the country's main island.

"It is very important for us to monitor continuously seismic activities close to the trench," researcher Hiroko Sugioka, a seismologist at the Japan Agency for Marine-Earth Science and Technology at Yokosuka, told OurAmazingPlanet. "It is mitigation against unexpectedly large tsunami disasters."

White Dwarfs Are Eating 'Earth-like' Planets for Dinner

2012-05-08T04:57:00.000-07:00

There is one doomsday scenario that will, without a doubt, come true.
In 4-5 billion years time, when the sun runs out of fuel, it will become a bloated red giant star. During this violent phase, it will blowtorch the Earth before shedding huge quantities of mass and disintegrating into a planetary nebula. A tiny white dwarf star will remain -- the remnant of our sun's core -- with the dust cloud of pulverized inner solar system planets raining down onto it.
Now, using data from the Hubble Space Telescope, astronomers from the University of Warwick have discovered four white dwarf stars containing dust in their atmospheres, giving us a rare glimpse into the future death of our own solar system.
Although dusty white dwarfs are a well-known astronomical phenomenon -- the extreme tidal shear and dynamical instability produced by a white dwarf will pulverize planetary bodies in orbit through a demolition derby of epic proportions -- these four new examples may be what our solar system will look like in a few billion years time.

In each case, the researchers have detected oxygen, magnesium, iron and silicon hanging in their stellar atmospheres. The presence of these elements are a telltale sign that rocky worlds used to exist in orbit. Interestingly, these four elements make up the composition of approximately 93 percent of the Earth.
In addition to these key elements is the detection of small quantities of carbon in proportions that closely match the proportion of carbon found inside the solar system's rocky planets. This is the first time such a proportion of carbon has been detected in the dusty debris surrounding white dwarfs.

Although the term "Earth-like" is often misrepresented in the field of exoplanetary studies, the Warwick astronomers are acutely aware of the implications of spotting these elements around distant stars. "What we are seeing today in these white dwarfs several hundred light-years away could well be a snapshot of the very distant future of the Earth," said lead researcher Boris Gänsicke.
Although we have little clue about the physical characteristics of the exoplanets before they were pulverized, all the components that make up the terrestrial planets -- Mercury, Venus, Earth, Mars and the asteroids -- are present in the white dwarfs' dust. The proportions of these elements are about as "Earth-like" as it gets.
There is one white dwarf, called PG0843+516, that stands out from the other three; it has an overabundance of iron, nickel and sulfur in its atmosphere. These particular elements are found in the cores of rocky planets. During planetary evolution, gravity pulls these elements into the core -- a process known as "differentiation." Differentiation will occur in large rocky worlds like Earth, forming a core, mantle, crust and, probably, tectonic activity.

Also, as the white dwarfs' gravity should consume these elements very quickly, the fact that they have been spotted in the star's atmosphere indicates a rocky planetary body is being ripped to shreds right now.
In all four white dwarfs, the researchers estimate 1 million kilograms of planetary material must be raining down into the stars every second. This is significant as they are witnessing the final stages of these star systems' death throes.
One can't help but wonder, if true "Earth-like" worlds are being pulverized and eaten by white dwarf stars, are the remnants of ancient extraterrestrial civilizations also being consumed?
This research has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.
Source: University of Warwick

Yellowstone Supervolcano's Size Exceeds Expectations

2012-04-27T04:32:00.001-07:00

Beneath Yellowstone National Park lurks a partially molten plume rising from the Earth's mantle, fueling the park's famous geysers and hot springs, and causing the crust above to bulge and recede in response to its forces.
Now researchers report that the source beneath the surface may be even more massive than previously thought. Using a new technique, they have created an image of the plume beneath Yellowstone showing the cyclone shape stretching at a 40-degree angle to the west at a depth of 200 miles for 400 miles east to west, as far as the new technique can reach.
This study does not make any predictions about future eruptions, which the USGS Yellowstone Volcano Observatory notes are of very low probability in any given millennium, since they have been separated in the past by 800,000 and 660,000 years.
When the Yellowstone supervolcano last erupted cataclysmically 640,000 years ago, it formed the Yellowstone Caldera, a 30 by 50 mile crater. Smaller, non-explosive eruptions have happened since, the most recent about 70,000 years ago.
Previous estimates of the plume have used seismic images, which measure the reflection of seismic waves from earthquakes off of different types of materials below the surface. They reached even deeper than the new images -- to more than 400 miles down.
The new method detects differences in electrical conductivity generated by the different types of rocks and minerals below Yellowstone National Park, which provides clues to what they are made of.
Using supercomputers, the research team, led by Michael Zhdanov of the University of Utah in Salt Lake City, created images of the plume based on the electromagnetic measurements from 115 stations in Idaho, Montana and Wyoming.
"We see that there is a partially melted, conductive plume at great depths starting in the mantle, and going up," Zhdanov said.
"It's a completely different technique, completely different data," he added. "It confirms that the plume is there, but it provides another view of the plume."
The plume's high conductivity suggests it contains high levels of silicate rocks and perhaps briny water, he said. The observation that the high conductivity plume is larger and angled differently than the one found with seismic imaging suggests that the plume of molten and partially molten rock may be surrounded by additional liquid including briny water, Zhdanov said.
"I think it's an important finding to have a new technique to corroborate the way that this hotspot is rising through the mantle," said Jake Lowenstern, USGS scientist in charge of the Yellowstone Volcano Observatory.
He noted that the finding does not indicate that the plume of molten material is necessarily bigger than earlier seismic images indicated, but that the plume's sphere of influence extends further than could be seen by the other technique. "You're looking at the effects of that plume but not necessarily the plume itself," he said.
"It doesn't have great effect on the actual risk from the much more shallow volcanic system," he added. While this plume provides the heat that ultimately reaches the surface, he said, with these new images, "you're looking at something that's way below the actual magma chamber that's responsible for the eruptions."

8.6 Magnitude Earthquake Strikes North Sumatra

2012-04-11T06:36:00.003-07:00

UPDATE (7:33 a.m. ET): An aftershock of magnitude 8.2 has struck at 16.4 km (10 miles) deep - at 617 km (383 miles) south southwest of the coast of Banda Aceh. We are continuing to monitor the situation. Follow sea level changes here.
A magnitude 8.6 earthquake struck North Sumatra, Indonesia, at 2:38 p.m. local time today. First estimated as a magnitude 8.7 by the U.S. Geological Survey, the earthquake originated 22.9 km (14.2 miles) below the Earth's crust and struck 434 kilometers (270 miles) southwest of the coast of Banda Aceh, the capital of Indonesia's Aceh province.

A tsunami watch and warning was put into effect for the Indian Ocean, immediately after the event. The power is out in Banda Aceh, where residents have moved to high ground, reported Sutopo Purwo Nugroho, a spokesman for the Indonesian National Disaster Management Agency.
The island of Simeulue, Prih Harjadi, and other coastal areas of Aceh are also on alert.
India has taken caution on Andaman and Nicobar Islands, where authorities have ordered people to move out of low-lying areas, CNN reported.
However the geophysics of today's quake do not indicate a repeat of Indonesia's 2004 earthquake is in progress. The magnitude 9.1 earthquake that struck in 2004 and triggered a tsunami that killed more than 200,000 people in 14 countries was a subduction megathrust earthquake closer to shore (250 kilometers south-southeast of Banda Aceh).
Today's temblor appears to have ripped along a transform fault, tearing the seafloor as opposed to popping it apart. Though local tsunami waves are a considerable risk, with calculations showing Simeulue could receive waves as high as 6 meters (20 feet) the widespread tsunami damage seen in 2004 is not anticipated.

IMAGES: Earthquake location map (USGS) Indian Ocean warning in effect (PTWC)

Monster Solar Tornadoes Discovered

2012-04-03T05:36:00.001-07:00

For the first time, huge solar tornadoes have been filmed swirling deep inside the solar corona -- the sun's superheated atmosphere. But if you're imagining the pedestrian tornadoes that we experience on Earth, think again.
These solar monsters, measuring the width of several Earths and swirling at speeds of up to 300,000 kilometers (190,000 miles) per hour, aren't only fascinating structures; they may also trigger violent magnetic eruptions that can have drastic effects on our planet.

In one example observed on Sept. 25, 2011, solar researchers from the UK used the high-definition cameras onboard NASA's Solar Dynamics Observatory (SDO) to track solar gases as hot as 2 million Kelvin (3.6 million degrees Fahrenheit) getting sucked from the bottom of a solar prominence and spiral high into the corona. The solar tornado then developed for three hours, gases traveling in spiral paths for around 200,000 kilometers (120,000 miles).
"Prominences are tangled magnetic fields trapping cold and dense plasma in the solar corona," Xing Li, solar physicist at Aberystwyth University, told Discovery News. "These often erupt spectacularly and fly out into space as coronal mass ejections (CMEs), and large CMEs will impact our space weather and space technology in a significant way when they are heading toward the Earth.
"What drives these eruptions is still not clear and is very important to gain an understanding of CME initiation (so that we can possibly predict such events)."

As mankind becomes more dependent on sensitive technology, it is critical that we develop new and more sophisticated ways to predict the sun's next "temper tantrum." As it turns out, these twisted tornadoes may hold the key to predicting when the next CME will be launched.
"This unique and spectacular tornado must play a role in triggering global solar storms," said co-discoverer Huw Morgan, also at Aberystwyth University.

"These tornadoes may help to produce favorable conditions for CMEs to occur," Li added, pointing out that the tornadoes his team studied coincided with CME eruptions as observed by other instruments monitoring the wider corona.
Also, the tornadoes observed so far by Li and Morgan often occur at the root of where CMEs are initiated. As the dynamic structures wind-up magnetic fields and drag powerful electric currents high into the corona, these tornadoes could generate the conditions ripe for CME eruptions, they theorize.

But to observe the tornadoes in the first place requires a bit of luck.
Firstly, as they are magnetic structures, if the tornado is empty of radiating plasma, they will remain invisible. Only when hot plasma is being dragged high into the corona can they be seen. Conversely, should the tornado be completely flooded with plasma, you wouldn't see the motion of the material as the radiating plasma would be completely washed out.

Li highlights the need for discrete objects inside the swirling mass so they can be tracked as they move around the tornado. He likens this to the dust and bits of debris that a terrestrial tornado would pick up. Without these objects, we couldn't "see" the spinning wind currents. The same goes for solar tornadoes; discrete "blobs" of plasma can be tracked as they are accelerated and carried high into the corona by the tornado's magnetic field.
"Also, we believe that the angle you view the tornado from is important," Li added. "For example, if you imagine the slinky structure mentioned above, if you view it from the side it may not appear so clearly as a tornado."
In the past, observers have spotted prominences that they described as "tornadoes," but in the days before the SDO was launched, the necessary definition and rapid image capturing techniques simply weren't available.

Fire and the Future of Yellowstone

2012-03-17T03:16:00.001-07:00

download large image (5 MB, JPEG, 3274x3274)

acquired August 2, 1989 download GeoTIFF file (24 MB, TIFF)

The high mountain forests of western North America need fire. Fire returns nutrients to the soil and replaces old stands and ground debris with young forest. Intense fires are a characteristic of the conifer forests, though they occur infrequently—once every 100 to 300 years.
The year 1988 brought one of those infrequent, severe fires to Yellowstone National Park. Drought and high temperatures combined to create extreme fire conditions. Fifty wildfires ignited, seven of which grew into major wildfires. By the end of the year, 793,000 acres had burned.
These images, taken by the Landsat satellites, contrast 1989 and 2011. Burned land is deep red in the 1989 image. By 2011, more than two decades later, the scar faded to tan-orange, but it was still present. Year-to-year images are available in the Earth Observatory’s World of Change article, Burn Recovery in Yellowstone.
Immediately after the fire, grass flourished in the ash-rich soil, followed by young trees. The slender saplings were still not dense enough to hide the burn scar. As these images indicate, it takes many decades for a conifer forest to recover to pre-fire conditions.
Western conifers burn when temperatures are high and plants and soil are dry. Such conditions will come together more frequently as the climate changes over the next century, and fires are already becoming more frequent. A 2011 study combined several climate models to estimate how fire could change in the Yellowstone ecosystem. Yellowstone is near a tipping point, the researchers assert, as warmer, dryer conditions will likely allow large fires to burn as frequently as every 30 years.
When fires occur infrequently, the forest has time to recover. More frequent fires, however, give the conifers little time to grow back. If this occurs, Yellowstone could lose its dense conifer forests and replace them with low montane woodland and grassland by 2050.

Is That The 'Death Star' Suckling on the Sun?

2012-03-16T03:15:00.000-07:00

What was that planet-sized 'Death Star'-like structure seen floating near the surface of the sun on Monday? Although sightings of supposed UFOs in space images are nothing new, this particular orb appears to be refueling with solar plasma -- there's even a hose extending from the sun's surface!
Anyone familiar with solar images will immediately recognize the filament extending from the surface of the sun into the sun's atmosphere (or corona) -- it's a solar prominence.

Prominences are very well-known structures in the corona. Although their formation is still the subject of intense scientific scrutiny, we know that they are clouds of cool plasma encapsulated in long tubes of magnetism. But 'cool' is a relative term.
Typically, prominences have been measured to be of chromospheric temperatures. The chromosphere -- a 2,000-kilometer thick region of the lower solar atmosphere that is sandwiched between the solar "surface" (the photosphere) and the multi-million degree corona -- can reach temperatures of up to 24,000 Kelvin (or degrees Celsius), and prominences have a similar temperature characteristic.
So why are they so dark when viewed by solar observatories?
When solar telescopes like NASA's Solar Dynamics Observatory (SDO) observe the sun, they do so through filters. These filters are able to select a certain wavelength of electromagnetic radiation. Each wavelength corresponds to a certain temperature -- generally higher temperatures produce radiation of shorter wavelengths. Therefore, the most powerful, hottest, solar flares may generate X-ray radiation (hence "X-class" flares), whereas the "quiet sun" (areas of the cool photosphere with little magnetic activity) generate longer wavelength radiation that we can see with our own eyes -- a.k.a. visible light.

The tenuous gas in the sun's corona is very hot, so when the SDO studies the corona, it uses a filter that is able to "see" the multi-million degree plasma emitting radiation in a specific point of the extreme-ultraviolet (or EUV) part of the electromagnetic spectrum.
Therefore, should cooler plasma -- such as the plasma encased in a long prominence -- be observed inside the corona, it won't be emitting the same wavelength as the corona and will appear dark.
But what about the strange orb shape attached to the end of the prominence? That's actually a tunnel, or "coronal cavity," carved into the corona by the magnetic structure atop the prominence.
"When you look at it from the edge of the sun, what you actually see is a spherical object. You're actually looking down the tunnel. And this tunnel sits up top of the filament," NASA solar physicst C. Alex Young explained on his website The Sun Today.
As we view the sun with more sophisticated space telescopes, our eyes are being opened to the incredible dynamics that connect the sun's interior to its atmosphere. And as this video shows, erupting coronal cavities can trigger the formation of CMEs. CMEs are the target for much scrutiny by space weather experts as they can have a dramatic impact on modern technology in space and on Earth, so understanding these features is paramount to predicting the sun's temper tantrums.

Meteorite Punches Hole Through Oslo Shed

2012-03-16T03:08:00.000-07:00

A Norwegian family was flabbergasted to find that what appeared to be a piece of a meteorite had crashed through the roof of their allotment garden hut in the middle of Oslo, media reported Monday.

The rock weighing 585 grams (1lb 4oz), which split in two, probably detached from a meteorite observed over Norway on March 1, experts said, and had landed on the empty hut in the Thomassen family's allotment in a working-class neighbourhood of the Norwegian capital.

Astrophysicist Knut Joergen Roed Oedegaard and his wife Anne Mette Sannes, a meteorite enthusiast, identified the object as a breccia, or a rock composed of broken fragments of minerals or rock.
"It is a sensation in more than one way. On one hand because it is rare that a piece of meteorite goes through a roof and on the other hand because it is a breccia, which is even harder to find," Sannes told AFP.
She said the owners of the meteorite pieces wanted to keep them in Norway, maybe in a museum.

Meteorites speed through space and generally break up as they enter our atmosphere, but it is extremely rare for the debris to fall on inhabited areas, according to Serge Koutchmy, a researcher at the Paris Astrophysical Institute.

"This family is very lucky," Koutchmy told AFP.
"First off because the piece of meteorite did not cause much damage, but also because it is worth a small fortune," he said.
A meteorite from Mars, for instance, can fetch around 5,000 kroner ($876) per gram (0.002 pounds), according to geophysicist Hans Amundsen quoted on the website of the Verdens Gang daily, adding though that it remained unclear where the meteorite pieces that landed in Oslo came from and how rare they were.

Nuking Asteroids: It's a Megaton Of Fun!

2012-03-16T03:01:00.001-07:00

Asteroids: they're big, scary and can kill millions. Nuclear weapons: they're big, scary and can kill millions. Wouldn't it make sense to unite the two? Seems like a perfect match.
We've gone full circle more than once in the discussion about asteroid collision mitigation plans in recent years. The once sci-fi space rock disposal solution is becoming more sci-fact every time the ugly subject of errant space rocks is discussed. It's a "given" that if an incoming asteroid were to be spotted last-minute, we'd obviously need to launch our entire nuclear deterrent into space.

Unfortunately, there's a catch (actually, there's a few catches) with this plan:
1) What if we shot a nuke at an incoming asteroid and it was woefully weak compared to the structure of the asteroid? All we'd succeed in doing is turn the deadly asteroid into a radioactive deadly asteroid.
2) What if we shot a nuke at an incoming asteroid, the asteroid blew up, but there's enough time for the asteroid to reform under the mutual gravity of its debris? Well, that's not good either.
3) What if we shot a nuke at an incoming asteroid, the asteroid blew up, but now we have a thousand smaller chunks of the deadly asteroid racing toward us? Well, it would be like choosing between getting shot by a cosmic bullet, or cosmic buckshot. The former packs a bigger punch, while the latter blanket-bombs an entire hemisphere.
With all these "what if's" we'd be stupid to launch a nuclear weapon at an asteroid, right?

Well, despite the flaws, it turns out that going nuclear is probably still the 'best' option if we spotted an "on-target Apophis" tomorrow, and a group of scientists have been busy simulating this event.
In a January video from Los Alamos National Laboratory, New Mexico, scientists using the awesome power of 32,000 processors inside the Cielo supercomputer have simulated the impact of a 1-megaton nuclear explosion on the surface of a 500-meter wide asteroid.
Their conclusion is fabulous: Yes, a big boom can solve a big problem.
"Ultimately this 1-megaton blast will disrupt all of the rocks in the rockpile of this asteroid, and if this were an Earth-crossing asteroid, would fully mitigate the hazard represented by the initial asteroid itself," said Los Alamos scientist Bob Weaver.
Basically, by detonating this nuclear warhead on the surface of an asteroid like the one visited by the Japanese Hayabusa asteroid sample return mission, a shock wave will propagate through the "rubble pile" (the nickname given to asteroids composed of loose material clumped together via a weak gravitational field), disrupting the asteroid enough so it can be pushed out of the way or ripped apart. It may not solve the problem of getting hit by lots of smaller pieces of asteroid, but if there's enough time, this debris may be pushed out of harm's way by the blast. Humans: 1, Asteroid: zero.

Most recently, the discovery of asteroid 2012 DA14 has prompted some concern that the next asteroid to hit Earth probably won't be of extinction-level proportions, but more of city- or country-sized proportions. The 150-meter wide DA14 definitely wont hit us in 2013, but it will pass under the orbit of geosynchronous satellites, a fact that seems a little too close for comfort.
And by only having a one-year warning, what could possibly be done to mitigate the impact risk if DA14 was on target?
It seems there are only two options. We either nuke it, as the Los Alamos research suggests, or let it hit us. (And yes, the latter is a viable option).

Solar Storm Paints Stunning Northern Lights: Big Pic

2012-03-16T02:49:00.000-07:00

March 9, 2012 -- Coronal mass ejections unleashed by Tuesday night's powerful X-class solar flares collided with Earth's magnetosphere yesterday morning, eventually sparking amazing displays of aurorae around the world.

PHOTOS: What is the Aurora Borealis?

This stunning photo comes courtesy of Jónína Óskarsdóttir in Faskrudsfjordur, Iceland, and shows the energy of the upper atmospheric activity.

"No words can describe the experience of the Northern Lights show tonight," said Óskarsdóttir on SpaceWeather.com. "This is just a 1s exposure!"

Although the initial impact of the CME was weaker than expected, the magnetic orientations have since aligned such as to deposit more energy into Earth's magnetosphere, intensifying the storm activity -- and the potential for more aurorae!

-- by Jason Major.

Solar Storm Warning Satellite on Last Legs

2012-03-14T03:22:00.000-07:00

Every time a giant solar storm -- like the one that blasted by Earth earlier this week -- rushes past NASA's Advanced Composition Explorer satellite, scientists at NOAA's space weather forecasting branch cringe.
The satellite, nicknamed ACE, provides the only advance notice of incoming high-energy particles from the sun which can wreak havoc on radio, GPS, satellite communications that are now embedded in modern life.

Launched in 1997, ACE gives forecasters advance notice if a storm is headed toward Earth. Its measurements of solar wind strength, magnetic fields and speed were key to forecasters' assessments Thursday that Earth would be spared a direct hit from a geomagnetic storm that left the sun on Tuesday.
But how much longer ACE will last is anyone's guess.

"It would be a very bad day for us if that spacecraft was not working," William Murtagh, program coordinator for NOAA's Space Weather Prediction Center in Boulder, Colo., told Discovery News.
"When an eruption occurs on the sun, there are still quite a few question marks as to if it's going to hit the Earth and when it's going to hit the Earth," Murtagh said.
Until the sun's free-flying and highly energetic outbursts, known as coronal mass ejections, hit the ACE spacecraft, forecasters don't know the orientation of their embedded magnetic fields. Depending on the polarity, or alignment, Earth's magnetic shield will either peel away, giving the highly charged particles more freedom to disturb electrically sensitive equipment and communications, or rebuff the particles, such as what happened during this week's outburst.

Stationed about 1 million miles from Earth, ACE provides early warning of what's headed toward Earth. NOAA says more than 22,000 utility operators, airlines, satellite owners, GPS users and others are signed up to receive space weather alerts and millions more get the information on NOAA's website.
"ACE is a single point of failure and it's old," Murtagh said. "Every time I have a space weather storm I cringe a little bit that our very own space weather satellite doesn't succumb to the storms I'm relying on it to help forecast."
Another satellite with space weather sensors was slated to be launched in 2003 by the ill-fated shuttle Columbia crew, but the spacecraft, known as Triana, was nixed by the Bush administration because of its backing by former vice president and Democratic presidential nominee Al Gore. (Informally, Triana was sometimes referred to as GoreSat.)
Gore championed the spacecraft for its ability to continuously relay live pictures of Earth from the vantage point of 1 million miles away in space, in hopes that the global view of the blue planet would rally environmental awareness.
"There were no technical reasons why it couldn't go. We were getting ready to send it the Cape (Kennedy Space Center) for launch and we got an order that the mission was not going to go," project scientist Adam Szabo, with NASA's Heliospheric Physics Laboratory at the Goddard Space Flight Center in Maryland, told Discovery News.
After its ride was canceled, Triana was put into storage at Goddard. It is now undergoing checkouts and refurbishments in preparation for rebirth as NOAA-operated space weather sentry. The U.S. Air Force is picking up launch costs and expects to issue a solicitation soon to get the satellite, now renamed the Deep Space Climate Observatory, or DSCOVR, a ride to space.
The camera championed by Gore is still part of the spacecraft, along with a trio of instruments to monitor space weather and sensors to measure reflected heat from Earth.
Launch is targeted for June 2014. The sun's 11-year solar cycle is expected to peak in May 2013. Heightened solar activity, which is ramping up this year, will continue for about the next six years.