Posted on by Nancy Atkinson

Wind Power From the Ocean (With Help from Space)

I drive regularly through Iowa and southern Minnesota in the US, and over the past few years wind farms have been popping up in that region up almost faster than corn grows. These massive wind turbines are awesome to see. But there may be an even better location for future wind farms than the breezy plains of the central United States: our oceans. Experts say ocean winds blow harder and with more reliable consistency than wind on land, which more than offsets the greater cost of building windmills offshore. Efforts to harness the energy potential of Earth’s ocean winds could soon gain an important new tool: global satellite maps from NASA. Scientists have been creating maps using nearly a decade of data from NASA’s QuikSCAT satellite that reveal ocean areas where winds could produce wind energy.

“Wind energy is environmentally friendly. After the initial energy investment to build and install wind turbines, you don’t burn fossil fuels that emit carbon,” said study lead author Tim Liu, a senior research scientist and QuikSCAT science team leader at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Like solar power, wind energy is green energy.”

The new maps created by QuickSCAT have many potential uses including planning the location of offshore wind farms to convert wind energy into electric energy. Ocean wind farms have less environmental impact than onshore wind farms, whose noise tends to disturb sensitive wildlife in their immediate area.

QuikSCAT, launched in 1999, tracks the speed, direction and power of winds near the ocean surface. Data from QuikSCAT, collected continuously by a specialized microwave radar instrument named SeaWinds, also are used to predict storms and enhance the accuracy of weather forecasts.

Wind energy has the potential to provide 10 to 15 percent of future world energy requirements, according to Paul Dimotakis, chief technologist at JPL. If ocean areas with high winds were tapped for wind energy, they could potentially generate 500 to 800 watts of energy per square meter, according to Liu’s research. Dimotakis notes that while this is slightly less than solar energy (which generates about one kilowatt of energy per square meter), wind power can be converted to electricity more efficiently than solar energy and at a lower cost per watt of electricity produced.

The new QuikSCAT maps, which add to previous generations of QuikSCAT wind atlases, also will be beneficial to the shipping industry by highlighting areas of the ocean where high winds could be hazardous to ships, allowing them to steer clear of these areas.

Scientists use the QuikSCAT data to examine how ocean winds affect weather and climate, by driving ocean currents, mixing ocean waters, and affecting the carbon, heat and water interaction between the ocean and the atmosphere.

News Source: NASA

Posted on by Nancy Atkinson

Sun-like Stars May Have Low Probability of Forming Planets

This protoplanetary disk in the Orion Nebula has a mass more than one hundredth that of the sun, the minimum needed to form a Jupiter-sized planet. Image credit: Bally et al 2000/Hubble Space Telescope & Eisner et al 2008/CARMA, SMA)

The Orion Nebula shines brilliantly, as it is packed with over 1,000 young stars in a region just a few light-years wide. With all those stars, there’s probably the potential for thousands of planets to one day form from the dust and gas surrounding these stars, right? Actually, according to a new study, fewer than 10 percent of stars in the Orion Nebula have enough surrounding dust to make a planet the size of Jupiter. And that doesn’t bode well for the planet-forming abilities of most stars, at least in forming planets the size of Jupiter or larger. “We think that most stars in the galaxy are formed in dense, Orion-like regions, so this implies that systems like ours may be the exception rather than the rule,” said Joshua Eisner lead author of the study from the University of California Berkeley. This finding is also consistent with the results of current planet searches, which are finding that only about 6 percent of stars surveyed have planets the size of Jupiter or larger.

In the observations of Orion’s central region of more than 250 known stars, the findings showed that only about 10 percent emit the wavelength radiation typically emitted by a warm disk of dust, (1.3-millimeter). Even fewer – less than 8 percent of stars surveyed – were found to have dust disks with masses greater than one-hundredth the mass of the sun, which is thought to be the lower mass limit for the formation of Jupiter-sized planets. The average mass of a protoplanetary disk in the region was only one-thousandth of a solar mass, the researchers calculated.

The study was done using the Combined Array for Research in Millimeter Astronomy (CARMA) in California, and the Submillimeter Array (SMA) atop Mauna Kea in Hawaii. Both facilities observe at millimeter wavelengths, which is ideal for piercing the clouds of dust and gas surrounding young stars to see their dense, dusty disks.

Four billion years ago our own sun may have been in a dense, open cluster like Orion. Because open clusters like Orion eventually become gravitationally unbound, they disperse over the course of billions of years, and as a result, the sun’s birth neighbors are long gone.

Eisner said studying star clusters like the Orion Nebula Cluster “helps our understanding of the typical mode of star and planet formation.”

However, another survey of the Taurus cluster, which is a lower-density star-forming region showed that more than 20 percent of its stars have enough mass to form planets. The difference is probably related to the tightly packed, hot stars of the Orion cluster, said John Carpenter, colleague of Eisner’s in the study.

“Somehow, the Orion cluster environment is not conducive to forming high mass disks or having them survive long, presumably due to the ionization field from the hot, massive OB stars , which you might expect would photoevaporate dust and lead to small disk masses,” he said.

News Source: UC Berkley

Posted on by Nancy Atkinson

The Yin and Yang of the NeXT Spacecraft

Hard and soft. Dark and bright. High and low. Wide and thin. JAXA and NASA. And that’s just one spacecraft. Japan’s space agency, JAXA and NASA are teaming up to create a new spacecraft to study the extreme environments of the universe. NeXT, which stands for New exploration X-Ray Telescope is a next generation x-ray astronomy satellite currently under development, with launch scheduled in 2013. While Japan will provide the main spacecraft and several instruments, NASA, and in particular the Goddard Space Flight Center just announced they will be adding a new instrument to the spacecraft, the High-Resolution Soft X-Ray Spectrometer (SXS). While the spacecraft’s main instrument will be its Hard X-ray Telescope (HXTs) the addition of SXS is just one of several complementary instruments that provide a “yin and yang” aspect to NeXT’s explorations, which hope to reveal new facets of the universe.

The concept of yin and yang involves two opposing, but at the same time, complementary aspects of any one phenomenon, or comparison of any two phenomena. NeXT will employ both those aspects. With the addition of NASA’s SXS, NeXT will be observing both so-called “hard” and “soft” x-rays. Hard x-rays are the highest energy x-rays, typically having energies greater than 10,000 electron volts (or 10 keV) while the lower energy x-rays are referred to as soft x-rays, which have less energy and longer wavelengths. Different types of instruments are needed to detect each kind.

Conventional X-ray mirrors usually can just concentrate on only soft X-rays up to 10 keV. NeXT’s HXTs will use a “super mirror” which has a multi-layer coating on the reflecting surface in order to observe hard X-rays. The mission designers plan to utilize this technique to extend the energy band of the X-ray mirrors by nearly an order of magnitude. Observation of hard X-rays will enable the study of the various acceleration phenomena in the universe, such as dark energy, cosmic rays and supernova remnants, which astronomers say can never be completely understood through the observations of the thermal phenomena below 10 keV.

We have known for some time that cosmic X-rays are accelerated by supernova remnants. But some cosmic X-rays have energy levels so high that they cannot possibly come from a supernova remnant. These high-energy or hard cosmic X-rays may have been created when galaxy clusters evolved. According to this theory, when the galaxy clusters, which were small at first, were colliding and merging into large ones, shock waves were created, which greatly accelerated the particles. NeXT, may confirm or refute this theory.

NeXT will have both a soft x-ray telescope and soft x-ray spectrometer. With these instruments, the spacecraft can investigate the nature of dark matter on large scales in the universe, and can also explore how bright galaxies and clusters of galaxies form and evolve.

“We are thrilled to have the opportunity to create a powerful new x-ray spectrometer that will open up a whole new realm in high energy astrophysics in collaboration with our partners in Japan,” said Richard L. Kelley, the Principal Investigator for the SXS mission at Goddard. We have a great team in place that is anxiously waiting to start work.”

To compliment the x-ray telescopes there will also be Wide-band X-ray Imagers (WXI) to cover a wide energy range. Because it is difficult to cover such a wide energy range with a single detector, NeXT will use a hybrid detector, which consists of an upper-stage, soft X-ray detector and a lower-stage, hard X-ray detector. It will use thinned X-ray CCDs (charged coupled devices) for the upper stage, which stop only the soft X-rays and and a CdTe (cadmium telluride) pixel detector for the lower stage.

Also in the suite of instruments is a Soft Gamma-ray detector (SGD), which is still under development. It will include an ultra-low background, high-sensitivity detector in soft gamma-ray band by combining an active shield and an pixel detector.

Charles Gay, deputy associate administrator for NASA’s Science Mission Directorate in Washington said missions like SXS and NeXT “expand NASA’s science through partnerships with international and commercial organizations,” – just another complimentary aspect of a mission full of yin and yang.

Original News Source: NASA,

Posted on by Nancy Atkinson

Phoenix Brings New Sample to Wet Chemistry Lab

The Phoenix Mars Lander used its robotic arm to deliver a second sample of soil for analysis by the spacecraft’s wet chemistry laboratory. Data received from Phoenix on Sunday night confirmed the soil was in the lab’s cell number 1. This image taken by the the lander’s Surface Stereo Imager shows the Robotic Arm scoop positioned over the Wet Chemistry Lab Cell 1 delivery funnel on Sol 41, or July 6. Test results will be compared in coming days to the results from the first Martian soil analyzed by the wet chemistry laboratory two weeks ago. That laboratory is part of Phoenix’s Microscopy, Electrochemistry and Conductivity Analyzer.



On Monday, Phoenix also tested a method for scraping up a sample of icy material and getting it into the scoop at the end of the robotic arm. Photography before, during and after the process will allow evaluation of this method. If the test goes well, the science team plans to use this method for gathering the next sample to be delivered to Phoenix’s bake-and-sniff instrument, the Thermal and Evolved-Gas Analyzer (TEGA). The science team wants to be as precise and quick as possible in delivering the next sample to TEGA, as it possibly could be the last time the ovens can be used because of a short circuit that may occur the next time the oven is activated.

News Source: U of Arizona

Posted on by Nancy Atkinson

Exploding Asteroid Theory Gains Evidence

About 13,000 years ago, woolly mammoths roamed the North American continent and the first known human society in that region, known as the Clovis civilization, lived there as well. But geologic and archeological evidence shows they both suddenly disappeared, and scientists have long debated the mystery of the mass extinction of both animals and humans about 12,900 years ago. At that time, climatic history suggests the Ice Age should have been drawing to a close, but instead rapid climate change initiated an additional 1,300 years of glacial conditions. But scientists couldn’t agree on the cause of the sudden change in climate. However, about two years ago geophysicist Allen West proposed that an asteroid or comet exploded just above the earth’s surface at that time over modern-day Canada, sparking a massive shock wave and heat-generating event that set large parts of the northern hemisphere ablaze, setting the stage for the extinctions. Another scientist set out to prove West wrong, but ended up finding evidence to support the exploding asteroid/comet theory.

Ken Tankersley, Anthropology professor at the University of Cincinnati studied sites in Ohio and Indiana that offers the strongest support yet for the exploding comet/asteroid theory. Samples of diamonds, gold and silver found in the region have been conclusively sourced through X-ray diffractometry to have come from the diamond fields region of Canada.

Tankersley and West both believe the best scenario to explain the presence of these materials this far south is the kind of cataclysmic explosive event described by West’s theory. “We believe this is the strongest evidence yet indicating a comet impact in that time period,” says Tankersley.

Previously, geologists believed the deposits of the gems and precious metals were brought south from the Great Lakes region by glaciers. But they are found at a soil depth consistent with the time frame of the comet/asteroid event.

“My smoking gun to disprove (West) was going to be the gold, silver and diamonds,” Tankersley says. “But what I didn’t know at that point was a conclusion he had reached that he had not yet made public – that the likely point of impact for the comet wasn’t just anywhere over Canada, but located over Canada’s diamond-bearing fields. Instead of becoming the basis for rejecting his hypothesis, these items became the very best evidence to support it.”

Additional work is being done at the sites looking for iridium, micro-meteorites and nano-diamonds that bear the markers of the diamond-field region, which also should have been blasted by the impact into this region.

As Tankersley, West and additional scientists compile more data, they’ll be looking for more clues to help explain the history of our planet and its climate.

“The kind of evidence we are finding does suggest that climate change at the end of the last Ice Age was the result of a catastrophic event,” Tankersley says. “The ultimate importance of this kind of work is showing that we can’t control everything,” he says. “Our planet has been hit by asteroids many times throughout its history, and when that happens, it does produce climate change.”

Original Source: Science Daily

Posted on by Nancy Atkinson

Satellites Keep an Eye on Wildfires Around the World

Wildfire season is underway in the northern hemisphere, and with hot and dry conditions in many areas this summer, fires have been plentiful. Regions affected include central Canada, California in the US, Southeastern Russia and Norway. While wildfires are a natural part of Earth’s environment when sparked by lightning strikes, these fires consume a million or more square kilometers per year. Wildfires can also be started from volcano eruptions, but humans also start many fires -sometimes accidentally, but mostly deliberately. Both NASA and ESA have Earth-watching satellites that have been keeping an eye on wildfires around the world. Above, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of wildfires in Central Canada, in the Saskatchewan and Manitoba Provinces on June 30, 2008. Places where the sensor detected actively burning fires are marked in red; a strong wind was blowing east-southeast and spreading thick plumes of gray-brown smoke.


Thunderstorms in California brought lightning but little rain, starting several wildfires. This natural-color image was captured by MODIS on July 2, 2008, and it shows the location of actively burning fires marked in red. The highest concentration of fires is in Northern California, where reportedly 68 uncontained large fires were burning as of July 3. Meanwhile, Southern California was battling the state’s two largest blazes, shown in the lower half of this image.

These false-color images of the Santa Lucia Range Mountains near Big Sur, California, was captured by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite on June 29, 2008. Vegetation is red, naturally bare ground is tan, burned ground is charcoal colored, and smoke is light blue. Clouds over the Pacific Ocean to the southwest are bright bluish white. Over 120,000 acres have been burned by the two large wildfires in this area.


With extremely hot weather conditions in Europe, Norway experienced its biggest forest fire in the last half century in June. ESA’s Envisat satellite images were used in the fire’s aftermath to get an overview of the damaged area for authorities and insurance companies. The Envisat Advanced Synthetic Aperture Radar (ASAR) image shows the burned area as a red cluster in the image center.

The fires (red dots) visible along the shoreline of Russia’s Khabarovsk Province at the upper left of this image are only a few of the forest fires responsible for the river of smoke spreading eastward over the Sea of Okhotsk and the Kamchatka Peninsula on July 2, 2008. This natural-color image of the area was captured by MODIS on NASA’s Aqua satellite. Like this image, many images area developed daily from orbiting satellites to to provide up-to-date satellite images of the Earth’s landmasses in near real time. The MODIS Rapid Response Team provides these images, many times with a few hours of being collected. This system is valuable resource for the international fire monitoring community, who use the images to track fires.

News sources: NASA’s Earth Observatory Natural Hazards site, ESA’s Observing the Earth site

Posted on by Nancy Atkinson

“Starlight Zone” Interview Now Online

The interview that I (Nancy) did with the “Starlight Zone” radio show from station 2NUR FM in Newcastle, Australia back on June 19 is now online (or just listen below). It’s only five minutes long, so if you need a short diversion to your day…. We talked about the concept of a one-way trip to Mars and the Phoenix mission.

Col Maybury, who does the show was a very fun guy to talk with. Check out all the past interviews he’s done with various “spacey” people on 2NUR’s “Starlight Zone” website.

G’day!

Posted on by Nancy Atkinson

Theory of Relativity Passes Another Test

Einstein’s theory of General Relativity has been around for 93 years, and it just keeps hanging in there. With advances in technology has come the ability to put the theory under some scrutiny. Recently, taking advantage of a unique cosmic coincidence, as well as a pretty darn good telescope, astronomers looked at the strong gravity from a pair of superdense neutron stars and measured an effect predicted by General Relativity. The theory came through with flying colors.

Einstein’s 1915 theory predicted that in a close system of two very massive objects, such as neutron stars, one object’s gravitational tug, along with an effect of its spinning around its axis, should cause the spin axis of the other to wobble, or precess. Studies of other pulsars in binary systems had indicated that such wobbling occurred, but could not produce precise measurements of the amount of wobbling.

“Measuring the amount of wobbling is what tests the details of Einstein’s theory and gives a benchmark that any alternative gravitational theories must meet,” said Scott Ransom of the National Radio Astronomy Observatory.

The astronomers used the National Science Foundation’s Robert C. Byrd Green Bank Telescope (GBT) to make a four-year study of a double-star system unlike any other known in the Universe. The system is a pair of neutron stars, both of which are seen as pulsars that emit lighthouse-like beams of radio waves.

“Of about 1700 known pulsars, this is the only case where two pulsars are in orbit around each other,” said Rene Breton, a graduate student at McGill University in Montreal, Canada. In addition, the stars’ orbital plane is aligned nearly perfectly with their line of sight to the Earth, so that one passes behind a doughnut-shaped region of ionized gas surrounding the other, eclipsing the signal from the pulsar in back.

Animation of double pulsar system

The eclipses allowed the astronomers to pin down the geometry of the double-pulsar system and track changes in the orientation of the spin axis of one of them. As one pulsar’s spin axis slowly moved, the pattern of signal blockages as the other passed behind it also changed. The signal from the pulsar in back is absorbed by the ionized gas in the other’s magnetosphere.

The pair of pulsars studied with the GBT is about 1700 light-years from Earth. The average distance between the two is only about twice the distance from the Earth to the Moon. The two orbit each other in just under two and a half hours.

“A system like this, with two very massive objects very close to each other, is precisely the kind of extreme ‘cosmic laboratory’ needed to test Einstein’s prediction,” said Victoria Kaspi, leader of McGill University’s Pulsar Group.

Theories of gravity don’t differ significantly in “ordinary” regions of space such as our own Solar System. In regions of extremely strong gravity fields, such as near a pair of close, massive objects, however, differences are expected to show up. In the binary-pulsar study, General Relativity “passed the test” provided by such an extreme environment, the scientists said.

“It’s not quite right to say that we have now ‘proven’ General Relativity,” Breton said. “However, so far, Einstein’s theory has passed all the tests that have been conducted, including ours.”

Original News Source: Jodrell Bank Observatory

Posted on by Nancy Atkinson

MESSENGER Provides New Insights on Mercury

mercury_plains..Credit: NASA/JHUAP/Arizona State University

Data from the MESSENGER spacecraft’s first flyby of Mercury in January of 2008 are now turning into science results. Several scientists discussed their findings at a press conference today highlighting the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission, the first spacecraft to visit Mercury since NASA’s Mariner 10 made three flyby passes in 1974 and 1975. Among the findings, scientists discovered volcanism has played a more extensive role in shaping the surface of Mercury than previously thought. MESSENGER data has also identified and mapped surface rock units that
correspond to lava flows, volcanos, and other geological features, showing an apparent planet-wide iron deficiency in Mercury’s surface rocks. Additionally, other instruments made the first observations about the surface and atmospheric composition of the closest world to the sun.

“We have now imaged half of the part of Mercury that was never seen by Mariner 10,” says Mark S. Robinson of Arizona State University, lead author of s study on composition variations in Mercury’s surface rocks using their multispectral colors. “The picture is still incomplete, but we’ll get the other half on October 6th.”

MESSENGER will make two more Mercury flybys (October 6, 2008 and September 29, 2009) before
going into orbit around the planet, March 18, 2011.

MESSENGER’s big-picture finding, says Robinson, is the widespread role played by volcanism. While impact craters are common, and at first glance Mercury still resembles the Moon, much of the planet has been resurfaced through volcanic activity.

“For example, according to our color data the Caloris impact basin is completely filled with smooth plains material that appears volcanic in origin,” Robinson explains. “In shape and form these deposits are very similar to the mare basalt flows on the Moon. But unlike the Moon, Mercury’s smooth plains are low in iron, and thus represent a relatively unusual rock type.”

Mercury’s surface also has a mysterious, widespread low-reflective material Robinson says, “It’s an important and widespread rock that occurs deep in the crust as well as at the surface, yet it has very little ferrous iron in its silicate minerals.”

Another experiment measured the charged particles in the planet Mercury’s magnetic field, which enabled the first observations about the surface and atmospheric composition of Mercury. “We now know more about what Mercury’s made of than ever before,” said Thomas Zurbuchen, a professor at the University of Michigan. “Holy cow, we found way more than we expected!”

Zurbuchen is project leader of the Fast Imaging Plasma Spectrometer (FIPS), a soda can-sized sensor on board the MESSENGER spacecraft.

FIPS detected silicon, sodium, sulfur and even water ions around Mercury. Ions are atoms or molecules that have lost electrons and therefore have an electric charge.

Because of the quantities of these molecules that scientists detected in Mercury’s space environment, they surmise that they were blasted from the surface or exosphere by the solar wind. The solar wind is a stream of charged particles emanating from the sun. It buffets Mercury, which is 2/3 closer to the sun than the Earth, and it causes particles from Mercury’s surface and atmosphere to sputter into space. FIPS measured these sputtered particles.

Mercury and MESSENGER form the subject of 11 papers in a special section devoted to the January flyby in the July 4, 2008, issue of the scientific journal Science.

News Sources: University of Arizona, MESSENGER site

Posted on by Nancy Atkinson

International Group Studies Mars Sample Return Mission

Until humans can actually set foot on the Red Planet, the next best thing would be a sample return mission, to bring Martian soil samples back to Earth. A sample return would exponentially increase our knowledge and understanding Mars and its environment. And in order to pull off a mission of this magnitude, international cooperation might be required, and in fact, may be preferred. The International Mars Exploration Working Group (IMEWG), organized an international committee to study an international architecture for a Mars Sample Return (MSR) mission concept. After several months of collective work by scientists and engineers from several countries worldwide, the “iMARS” group is ready to publish the outcome of its deliberations and the envisioned common architecture for a future international MSR mission, and they will discuss their findings at an international conference on July 9 and 10 in France.

The conference will be held at the Auditorium of the Bibliothèque Nationale de France in Paris, and will bring together members of the scientific and industrial communities as well as representatives of space agencies around the world to discuss the status and prospects for Mars exploration over the coming decades. Attendees will have the opportunity to hear the current international thinking on Mars Sample Return and to interact with key players in the global endeavor of exploring and understanding Mars.

A Mars Sample Return mission would use robotic systems and a Mars ascent rocket to collect and send samples of Martian rocks, soils, and atmosphere to Earth for detailed chemical and physical analysis. Researchers on Earth could measure chemical and physical characteristics much more precisely than they could by via remote control. On Earth, they would have the flexibility to make changes as needed for intricate sample preparation, instrumentation, and analysis if they encountered unexpected results. In addition, for decades to come, the collected Mars rocks could yield new discoveries as future generations of researchers apply new technologies in studying them.

Keynote speakers at the upcoming conferencewill are Steve Squyres of Cornell University, principal investigator under the MER mission, and Jean-Pierre Bibring of the Institut d’Astrophysique Spatiale, principal investigator for a key instrument on Mars Express.

Interested in attending? Check out their website

Original News Source: ESA