Unseen Is Free

Unseen Is Free
Try It Now

Google Translate

No censorship at seen.life

Wednesday, May 25, 2016

Other Worldly Philately: New Stamps Honoring NASA Planetary Discoveries Debut May 31

With this pane of 16 Forever stamps, the Postal Service showcases some of the more visually compelling historic, full-disk images of the planets obtained during the last half-century of NASA space exploration. Eight new colorful Forever stamps – each shown twice – feature Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.


Credits: USPS/Antonio Alcalá © 2016 USPS

Coming next week to a post office near you: new “Views of Our Planets” Forever stamps featuring iconic images of the planets in our solar system, including the well-known “Blue Marble” photo of Earth. New “Pluto Explored” Forever stamps commemorating the July 2015 flyby of Pluto by NASA’s New Horizons spacecraft also are being issued for online purchase.

The May 31 first-day-of-issue dedication ceremony for the Pluto and planetary stamps will be in New York City at World Stamp Show-NY 2016. This international gathering of stamp collectors occurs only once each decade in the United States, and – with more than 250,000 visitors expected to attend – is the largest stamp show in the world.

“The unveiling of these breathtaking new images of Pluto and our planets will be an exciting day for NASA and for all who love space exploration, said Jim Green, director of planetary science at NASA Headquarters in Washington. “With the 2015 Pluto flyby, we’ve completed the initial reconnaissance of the solar system, and we’re grateful to the U.S. Postal Service for commemorating this historic achievement.”

Green will be among featured speakers and honored guests at an 11 a.m. EDT ceremony at the Jacob Javits Convention Center in New York. Among other VIPs scheduled to attend are: Dave Williams, chief operating officer and executive vice president of the U.S. Postal Service; NASA Chief Scientist Ellen Stofan; John Grunsfeld, astronaut and former associate administrator for NASA’s Science Mission Directorate; New Horizons Principal Investigator Alan Stern, Southwest Research Institute; New Horizons Mission Operations Manager Alice Bowman, Johns Hopkins University Applied Physics Laboratory (APL); and Norman Kuring, oceanographer at NASA’s Goddard Space Flight Center.

The souvenir sheet of four New Horizons stamps features two new stamps appearing twice. The first stamp is an artist’s rendering of NASA’s New Horizons spacecraft based on artwork created by APL’s Steve Gribben, while the second stamp shows an enhanced color image of Pluto taken by New Horizons near its closest approach to Pluto.

Credits: USPS/Antonio Alcalá © 2016 USPS

The Pluto stamps are of special significance to NASA and the New Horizons team, which placed a 29-cent 1991 “Pluto: Not Yet Explored” stamp on board the APL-built spacecraft. On July 14, 2015, New Horizons carried the stamp on its history-making journey to Pluto and beyond, as jubilant members of the mission team celebrated with a large print, striking the words “not yet.”

Pluto Explored. (left to right): New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, Colorado; New Horizons’ Deputy Project Scientist Leslie Young, SwRI; APL Director Ralph Semmel; Annette Tombaugh, daughter of Clyde Tombaugh, who discovered Pluto in 1930; and New Horizons Co-Investigator Will Grundy, Lowell Observatory, Flagstaff, Arizona, hold a print of the 1991 Pluto stamp – with their suggested update – on July 14, 2015 at APL in Laurel, Maryland.

Credits: NASA/Bill Ingalls


“The 1991 stamp that showed Pluto 'not yet explored’ highlighted some important, unfinished business for NASA’s first exploration of the planets of our solar system,” said Stern. “I’m thrilled that 25 years later, these new stamps recognize that Pluto has, indeed, been explored by the New Horizons spacecraft and has been revealed to be a complex and fascinating world.”

The new “Views of our Planets” stamps will be widely available across the U.S. at post offices and for online purchase beginning May 31. The Pluto—Explored! Forever stamps will only be sold online or by calling 800-782-6724.


Contacts and sources:
Tricia Talbert
NASA

Fires Seen from Space: Alberta Oilsands More than 2000 Square Miles Blazing

NASA has published a satellite view of the Alberta oilsands fire showing no growth on May 24.

Firefighters in Alberta are grateful for and welcomed in the same weather than the North Atlantic residents of the United States have been dealing with and dreading for weeks. Cool, damp weather finally moved in across Alberta during the Victoria Day long-weekend ushering in improved conditions which have allowed some re-entry to oilsands facilities.

On Sunday, the blaze was estimated to be 522,894 hectares (2019 sq. miles) on the Alberta side, and 2,496 hectares (9.6 sq. miles) across the border into Saskatchewan. There was no change to the size of the fire which is welcome news in that the fire has not grown.
Fort McMurray fires and smoke
NASA image courtesy Jeff Schmaltz LANCE/EOSDIS MODIS Rapid Response Team, GSFC.

The mandatory evacuation of Fort McMurray and Anzac remains in place. Officials have stated that residents are expected to be able to start returning home on June 1 on a voluntary, phased basis.

NASA's Aqua satellite collected this natural-color image of the Fort McMurray fire complex in Alberta, Canada with the Moderate Resolution Imaging Spectroradiometer, MODIS, instrument on May 23, 2016. Smoke still rises in huge columns above the fires and actively burning areas, detected by MODIS’s thermal bands, are outlined in red.

Central Africa's farm fires seen from Space

Each red dot represents an area of the earth that is hotter than the area surrounding it and is indicative of fire. Central Africa in this satellite image is teeming with red dots. That signals that agricultural season in this area is in full swing. The location, widespread nature, and number of fires suggest that these were deliberately set to manage land. Farmers often use fire as a means of returning nutrients to the soil and to clear the ground of unwanted plants. While fire helps enhance crops and grasses for pasture, the fires also produce smoke that degrades air quality.
Central Africa blanketed by agricultural fires
NASA's Suomi NPP satellite collected this natural-color image using the VIIRS (Visible Infrared Imaging Radiometer Suite) instrument on May 18, 2016. NASA image courtesy Jeff Schmaltz LANCE/EOSDIS MODIS Rapid Response Team, GSFC. Caption by Lynn Jenner


Contacts and sources:
Editor: Lynn Jenner

Tycho Supernova Explosion 15 Years Condensed into Seconds: Chandra Movie Captures Expanding Debris from a Star's Demise

An explosion too big for even Hollywood.  A spectacle hundreds of years in the making. 

When the star that created this supernova remnant exploded in 1572, it was so bright that it was visible during the day. And though he wasn’t the first or only person to observe this stellar spectacle, the Danish astronomer Tycho Brahe wrote a book about his extensive observations of the event, gaining the honor of it being named after him.

Animations of Chandra observations from 2000 through 2015 of the Tycho supernova remnant’s X-ray evolution over time.
Image credits: X-ray: NASA/CXC/GSFC/B. Williams et al; Optical: DSS; Radio: NSF/NRAO/VLA

In modern times, astronomers have observed the debris field from this explosion − what is now known as Tycho’s supernova remnant − using data from NASA’s Chandra X-ray Observatory, the NSF’s Karl G. Jansky Very Large Array (VLA) and many other telescopes. Today, they know that the Tycho remnant was created by the explosion of a white dwarf star, making it part of the so-called Type Ia class of supernovas used to track the expansion of the Universe.

Since much of the material being flung out from the shattered star has been heated by shock waves − similar to sonic booms from supersonic planes − passing through it, the remnant glows strongly in X-ray light. Astronomers have now used Chandra observations from 2000 through 2015 to create the longest movie of the Tycho remnant’s X-ray evolution over time, using five different images. This shows the expansion from the explosion is still continuing about 450 years later, as seen from Earth’s vantage point roughly 10,000 light years away.

By combining the X-ray data with some 30 years of observations in radio waves with the VLA, astronomers have also produced a movie, using three different images. Astronomers have used these X-ray and radio data to learn new things about this supernova and its remnant.

This image comes from a very deep Chandra observation of the Tycho supernova remnant, produced by the explosion of a white dwarf star in our Galaxy. Low-energy X-rays (red) in the image show expanding debris from the supernova explosion and high energy X-rays (blue) show the blast wave, a shell of extremely energetic electrons
Credits: X-ray: NASA/CXC/Rutgers/K.Eriksen et al.; Optical: DSS 2011

The researchers measured the speed of the blast wave at many different locations around the remnant. The large size of the remnant enables this motion to be measured with relatively high precision. Although the remnant is approximately circular, there are clear differences in the speed of the blast wave in different regions. The speed in the right and lower right directions is about twice as large as that in the left and the upper left directions. This difference was also seen in earlier observations.

This range in speed of the blast wave’s outward motion is caused by differences in the density of gas surrounding the supernova remnant. This causes an offset in position of the explosion site from the geometric center, determined by locating the center of the circular remnant. The astronomers found that the size of the offset is about 10% of the remnant’s current radius, towards the upper left of the geometric center. The team also found that the maximum speed of the blast wave is about 12 million miles per hour.

Offsets such as this between the explosion center and the geometric center could exist in other supernova remnants. Understanding the location of the explosion center for Type Ia supernovas is important because it narrows the search region for a surviving companion star. Any surviving companion star would help identify the trigger mechanism for the supernova, showing that the white dwarf pulled material from the companion star until it reached a critical mass and exploded. The lack of a companion star would favor the other main trigger mechanism, where two white dwarfs merge causing the critical mass to be exceeded, leaving no star behind.

Tycho's Supernova Remnant, 2009 
See Explanation.  Clicking on the picture will download
 the highest resolution version available.
Credit: X-ray: NASA/CXC/SAO; Infrared: NASA/JPL-Caltech; Optical: MPIA, Calar Alto, O. Krause et al.

The significant offset from the center of the explosion to the remnant’s geometric center is a relatively recent phenomenon. For the first few hundred years of the remnant, the explosion’s shock was so powerful that the density of gas it was running into did not affect its motion. The density discrepancy from the left side to the right has increased as the shock moved outwards, causing the offset in position between the explosion center and the geometric center to grow with time. So, if future X-ray astronomers, say 1,000 years from now, do the same observation, they should find a much larger offset.

A paper describing these results has been accepted for publication in The Astrophysical Journal Letters and is available online. The authors are Brian Williams (NASA's Goddard Space Flight Center and Universities Space Research Association), Laura Chomiuk (Michigan State University), John Hewitt (University of North Florida), John Blondin (North Carolina State University), Kazimierz Borkowski (NCSU), Parviz Ghavamian (Towson University), Robert Petre (GSFC), and Stephen Reynolds (NCSU).

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.



Contacts and sources:
NASA's Chandra X-ray Observatory

From “Black Hole Seeds" Monster Black Holes Are Born

Using data from NASA’s Great Observatories, astronomers have found the best evidence yet for cosmic seeds in the early universe that should grow into supermassive black holes.

Researchers combined data from NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope to identify these possible black hole seeds. They discuss their findings in a paper that will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.

This illustration represents the best evidence to date that the direct collapse of a gas cloud produced supermassive black holes in the early Universe. Researchers combined data from NASA’s Chandra, Hubble, and Spitzer telescopes to make this discovery.

Credits: NASA/CXC/STScI

“Our discovery, if confirmed, explains how these monster black holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa, Italy, who led the study. “We found evidence that supermassive black hole seeds can form directly from the collapse of a giant gas cloud, skipping any intermediate steps.”

Scientists believe a supermassive black hole lies in the center of nearly all large galaxies, including our own Milky Way. They have found that some of these supermassive black holes, which contain millions or even billions of times the mass of the sun, formed less than a billion years after the start of the universe in the Big Bang.

One theory suggests black hole seeds were built up by pulling in gas from their surroundings and by mergers of smaller black holes, a process that should take much longer than found for these quickly forming black holes.

These new findings suggest instead that some of the first black holes formed directly when a cloud of gas collapsed, bypassing any other intermediate phases, such as the formation and subsequent destruction of a massive star.

“There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are narrowing in on an answer, where the black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”

The researchers used computer models of black hole seeds combined with a new method to select candidates for these objects from long-exposure images from Chandra, Hubble, and Spitzer.

The team found two strong candidates for black hole seeds. Both of these matched the theoretical profile in the infrared data, including being very red objects, and also emit X-rays detected with Chandra. Estimates of their distance suggest they may have been formed when the universe was less than a billion years old


This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole’s event horizon, where no light can escape the massive object’s gravitational grip. The black hole’s powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.
Credits: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)

“Black hole seeds are extremely hard to find and confirming their detection is very difficult,” said Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy. “However, we think our research has uncovered the two best candidates to date.”

The team plans to obtain further observations in X-rays and the infrared to check whether these objects have more of the properties expected for black hole seeds. Upcoming observatories, such as NASA’s James Webb Space Telescope and the European Extremely Large Telescope will aid in future studies by detecting the light from more distant and smaller black holes. Scientists currently are building the theoretical framework needed to interpret the upcoming data, with the aim of finding the first black holes in the universe.

“As scientists, we cannot say at this point that our model is ‘the one’,” said Pacucci. “What we really believe is that our model is able to reproduce the observations without requiring unreasonable assumptions.”

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program while the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission, whose science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado.


Contacts and sources:
Felicia Chou / Sean Potter
NASA

Cosmic Mysteries: Possible Link Between Primordial Black Holes and Dark Matter

Dark matter is a mysterious substance composing most of the material universe, now widely thought to be some form of massive exotic particle. An intriguing alternative view is that dark matter is made of black holes formed during the first second of our universe's existence, known as primordial black holes. 

Dark matter is a hypothetical type of matter composing the approximately 27% of the mass and energy in the observable universe that is not accounted for by dark energy, baryonic matter, and neutrinos. The name refers to the fact that it does not emit or interact with electromagnetic radiation, such as light, and is thus invisible to the entire electromagnetic spectrum.  The most widely accepted hypothesis on the form for dark matter is that it is composed of weakly interacting massive particles (WIMPs) that interact only through gravity and the weak force.

Now a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, suggests that this interpretation aligns with our knowledge of cosmic infrared and X-ray background glows and may explain the unexpectedly high masses of merging black holes detected last year.

"This study is an effort to bring together a broad set of ideas and observations to test how well they fit, and the fit is surprisingly good," said Alexander Kashlinsky, an astrophysicist at NASA Goddard. "If this is correct, then all galaxies, including our own, are embedded within a vast sphere of black holes each about 30 times the sun's mass."

In 2005, Kashlinsky led a team of astronomers using NASA's Spitzer Space Telescope to explore the background glow of infrared light in one part of the sky. The researchers reported excessive patchiness in the glow and concluded it was likely caused by the aggregate light of the first sources to illuminate the universe more than 13 billion years ago. Follow-up studies confirmed that this cosmic infrared background (CIB) showed similar unexpected structure in other parts of the sky.

 This image from NASA's Spitzer Space Telescope shows an infrared view of a sky area in the constellation Ursa Major.  

After masking out all known stars, galaxies and artifacts and enhancing what's left, an irregular background glow appears. This is the cosmic infrared background (CIB); lighter colors indicate brighter areas.  The CIB glow is more irregular than can be explained by distant unresolved galaxies, and this excess structure is thought to be light emitted when the universe was less than a billion years old. Scientists say it likely originated from the first luminous objects to form in the universe, which includes both the first stars and black holes.
Credits: NASA/JPL-Caltech/A. Kashlinsky (Goddard)

In 2013, another study compared how the cosmic X-ray background (CXB) detected by NASA's Chandra X-ray Observatory compared to the CIB in the same area of the sky. The first stars emitted mainly optical and ultraviolet light, which today is stretched into the infrared by the expansion of space, so they should not contribute significantly to the CXB.

Yet the irregular glow of low-energy X-rays in the CXB matched the patchiness of the CIB quite well. The only object we know of that can be sufficiently luminous across this wide an energy range is a black hole. The research team concluded that primordial black holes must have been abundant among the earliest stars, making up at least about one out of every five of the sources contributing to the CIB.

The nature of dark matter remains one of the most important unresolved issues in astrophysics. Scientists currently favor theoretical models that explain dark matter as an exotic massive particle, but so far searches have failed to turn up evidence these hypothetical particles actually exist. NASA is currently investigating this issue as part of its Alpha Magnetic Spectrometer and Fermi Gamma-ray Space Telescope missions.

"These studies are providing increasingly sensitive results, slowly shrinking the box of parameters where dark matter particles can hide," Kashlinsky said. "The failure to find them has led to renewed interest in studying how well primordial black holes -- black holes formed in the universe's first fraction of a second -- could work as dark matter."

Physicists have outlined several ways in which the hot, rapidly expanding universe could produce primordial black holes in the first thousandths of a second after the Big Bang. The older the universe is when these mechanisms take hold, the larger the black holes can be. And because the window for creating them lasts only a tiny fraction of the first second, scientists expect primordial black holes would exhibit a narrow range of masses.

On Sept. 14, gravitational waves produced by a pair of merging black holes 1.3 billion light-years away were captured by the Laser Interferometer Gravitational-Wave Observatory (LIGO) facilities in Hanford, Washington, and Livingston, Louisiana. This event marked the first-ever detection of gravitational waves as well as the first direct detection of black holes. The signal provided LIGO scientists with information about the masses of the individual black holes, which were 29 and 36 times the sun's mass, plus or minus about four solar masses. These values were both unexpectedly large and surprisingly similar.

"Depending on the mechanism at work, primordial black holes could have properties very similar to what LIGO detected," Kashlinsky explained. "If we assume this is the case, that LIGO caught a merger of black holes formed in the early universe, we can look at the consequences this has on our understanding of how the cosmos ultimately evolved."

Primordial black holes, if they exist, could be similar to the merging black holes detected by the LIGO team in 2014. This computer simulation shows in slow motion what this merger would have looked like up close. The ring around the black holes, called an Einstein ring, arises from all the stars in a small region directly behind the holes whose light is distorted by gravitational lensing. The gravitational waves detected by LIGO are not shown in this video, although their effects can be seen in the Einstein ring. 

Credits: SXS Lensing

Gravitational waves traveling out behind the black holes disturb stellar images comprising the Einstein ring, causing them to slosh around in the ring even long after the merger is complete. Gravitational waves traveling in other directions cause weaker, shorter-lived sloshing everywhere outside the Einstein ring. If played back in real time, the movie would last about a third of a second.

In his new paper, published May 24 in The Astrophysical Journal Letters, Kashlinsky analyzes what might have happened if dark matter consisted of a population of black holes similar to those detected by LIGO. The black holes distort the distribution of mass in the early universe, adding a small fluctuation that has consequences hundreds of millions of years later, when the first stars begin to form.

For much of the universe's first 500 million years, normal matter remained too hot to coalesce into the first stars. Dark matter was unaffected by the high temperature because, whatever its nature, it primarily interacts through gravity. Aggregating by mutual attraction, dark matter first collapsed into clumps called minihaloes, which provided a gravitational seed enabling normal matter to accumulate. Hot gas collapsed toward the minihaloes, resulting in pockets of gas dense enough to further collapse on their own into the first stars. Kashlinsky shows that if black holes play the part of dark matter, this process occurs more rapidly and easily produces the lumpiness of the CIB detected in Spitzer data even if only a small fraction of minihaloes manage to produce stars.

As cosmic gas fell into the minihaloes, their constituent black holes would naturally capture some of it too. Matter falling toward a black hole heats up and ultimately produces X-rays. Together, infrared light from the first stars and X-rays from gas falling into dark matter black holes can account for the observed agreement between the patchiness of the CIB and the CXB.

Occasionally, some primordial black holes will pass close enough to be gravitationally captured into binary systems. The black holes in each of these binaries will, over eons, emit gravitational radiation, lose orbital energy and spiral inward, ultimately merging into a larger black hole like the event LIGO observed.

"Future LIGO observing runs will tell us much more about the universe's population of black holes, and it won't be long before we'll know if the scenario I outline is either supported or ruled out," Kashlinsky said.

Kashlinsky leads science team centered at Goddard that is participating in the European Space Agency's Euclid mission, which is currently scheduled to launch in 2020. The project, named LIBRAE, will enable the observatory to probe source populations in the CIB with high precision and determine what portion was produced by black holes.




Contacts and sources:
By Francis Reddy
NASA's Goddard Space Flight Center

Why the Most Tornadoes in May? Five Things You Need To Know About Tornadoes

In May when tornadoes are in the news, the National Science Foundation (NSF) spoke with tornado expert and NSF Assistant Director for Geosciences Roger Wakimoto to learn more about these deadly storms -- including what new studies are telling us about how, where and when twisters form. The results will offer scientists better ways of predicting tornadoes.

1. Why does the U.S. seem to experience the most tornadoes in May?

The highest average number of U.S. tornadoes per month is in May, followed by June. May is the time when the two ingredients that are required -- very unstable air and strong vertical wind shear -- are most common. That being said, we’re now seeing a trend of tornadoes breaking out earlier in spring, such as April or even March. 

Image of a strong tornado near Arab, Alabama, part of the outbreak on April 27, 2011.

Credit: Charles Whisenant

2. What U.S. states/regions have the most tornadoes, and why?

The Great Plains is where the most tornadoes occur; the region is often referred to as Tornado Alley. It’s an ideal location due to warm, humid air flowing northward from the Gulf of Mexico at low levels, and cold, dry air coming down from Canada at upper levels, producing very unstable air. Beyond the Great Plains, tornadoes occurring over the southeastern U.S. have recently attracted scientists’ interest.

3. Are there tornadoes in countries other than the U.S.?

Tornadoes are typical in the mid-latitudes, between 30 and 50 degrees north and south. Countries that experience tornadoes include Bangladesh, Japan, Australia, New Zealand, China, South Africa, Argentina and many nations in Europe.

Tornado at beginning of life - condensation funnel has not yet reached ground.
Credit: NOAA Photo Library, National Severe Storms Laboratory (NSSL) Collection

4. What are we learning about how and when tornadoes form?

Tornadoes usually occur in association with particular types of severe storms, such as supercells and squall lines, called tornado parental storms. But not all these parental storms generate tornadoes. Tornadogenesis, as the formation of tornadoes is called, remains the “holy grail” of tornado research. Recent work suggests that the temperature of the outflow air from the parent thunderstorm could play a critical role. There is a lot we don’t yet understand, including the circumstances that produce tornado outbreaks. 

A large wall cloud arcs around a rotating thunderstorm updraft. This storm was documented by the VORTEX2 field campaign on June 6, 2010 near Ogallala, Nebraska.
Credit: Roger Wakimoto

5. What will NSF-supported tornado research underway this spring tell us?

A field project called TWIRL (Tornadic Winds: In situ and Radar measurements at Low-levels) is now taking place. It will improve our understanding of tornadogenesis and tornado evolution. The research includes the use of three Doppler on Wheels (DOW) mobile radars, and vehicles with deployable pods for weather observations. Scientists Karen Kosiba and Josh Wurman of the Center for Severe Weather Research are conducting this follow-up study to the past NSF-funded VORTEX-2 field campaign.

NSF is also working with NOAA on a Congressionally-mandated project called VORTEX-SE, which focuses on studies of tornadoes that bring deadly threats to the southeastern U.S. NSF is supporting scientists from academic institutions, who are working with researchers at NOAA laboratories to conduct ongoing field research.

Project Vortex. The Dimmitt Tornado. June 2 1995
File:Dimmitt Tornado1 - NOAA.jpg
'Credit: Harald Richter/ NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL)

From these efforts, we hope to discover critical information about which storms are most likely to produce tornadoes so forecasters can issue earlier warnings.


Contacts and sources:
 Cheryl Dybas, NSF


Oh My! Flying RoboBees, Tiny Surveillance Helicopters and Swarms of Smart Gliders

Flying micro-robots have a fine future carrying out almost every imaginable task in surveillance and detection.  You can run but it is getting harder and harder to hide.

In a recent article in Science, Harvard roboticists demonstrated that their flying microrobots, nicknamed the RoboBees, can now perch during flight to save energy - like bats, birds or butterflies.

RoboBee
Credit: Harvard Robotics Lab, Harvard University

“Many applications for small drones require them to stay in the air for extended periods,” said Moritz Graule, first author of the paper who conducted this research as a student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Wyss Institute for Biologically Inspired Engineering at Harvard University. “Unfortunately, smaller drones run out of energy quickly. We want to keep them aloft longer without requiring too much additional energy.”

The team found inspiration in nature and simple science.

“A lot of different animals use perching to conserve energy,” said Kevin Ma, a post-doc at SEAS and the Wyss Institute and coauthor. “But the methods they use to perch, like sticky adhesives or latching with talons, are inappropriate for a paperclip-size microrobot, as they either require intricate systems with moving parts or high forces for detachment.”

Instead, the team turned to electrostatic adhesion — the same basic science that causes a static-charged sock to cling to a pants leg or a balloon to stick to a wall.

When you rub a balloon on a wool sweater, the balloon becomes negatively charged. If the charged balloon is brought close to a wall, that negative charge forces some of the wall’s electrons away, leaving the surface positively charged. The attraction between opposite charges then causes the balloon to stick to the wall.

“In the case of the balloon, however, the charges dissipate over time, and the balloon will eventually fall down,” said Graule. “In our system, a small amount of energy is constantly supplied to maintain the attraction.”

The RoboBee, pioneered at the Harvard Microrobotics Lab, uses an electrode patch and a foam mount that absorbs shock. The entire mechanism weighs 13.4 mg, bringing the total weight of the robot to about 100mg — similar to the weight of a real bee. The robot takes off and flies normally. When the electrode patch is supplied with a charge, it can stick to almost any surface, from glass to wood to a leaf. To detach, the power supply is simply switched off.



“One of the biggest advantages of this system is that it doesn’t cause destabilizing forces during disengagement, which is crucial for a robot as small and delicate as ours,” said Graule.

The patch requires about 1000 times less power to perch than it does to hover, offering to dramatically extend the operational life of the robot. Reducing the robot’s power requirements is critical for the researchers, as they work to integrate onboard batteries on untethered RoboBees.

“The use of adhesives that are controllable without complex physical mechanisms, are low power, and can adhere to a large array of surfaces is perfect for robots that are agile yet have limited payload – like the RoboBee,” added Robert Wood, Charles River Professor of Engineering and Applied Sciences at SEAS, a core faculty member of the Wyss Institute, and senior author of the study. “When making robots the size of insects, simplicity and low power are always key constraints.”

Right now, the RoboBee can only perch under overhangs and on ceilings, as the electrostatic patch is attached to the top of the vehicle. Next, the team hopes to change the mechanical design so that the robot can perch on any surface.

“There are more challenges to making a robust, robotic landing system but this experimental result demonstrates a very versatile solution to the problem of keeping flying microrobots operating longer without quickly draining power,” said Ma.

The paper was coauthored by Pakpong Chirarattananon, Sawyer B. Fuller, Noah Jafferis, Matthew Spenko and Roy Kornbluh. The research was funded by the National Science Foundation, the Wyss Institute for Biologically Inspired Engineering, and the Swiss Study Foundation.

Flying micro-drones are of great interest to the military. Prox Dynamics is selling a micro-drone designed to give a squad of Marines their own tiny surveillance capability. The PD-100 Black Hornet weighs 18 grams and its body is around the size of a hummingbird. It comes in a day version that snags full-motion video and a night version that can capture thermal images.

The British Army Black Hornet Nano UAV is a military micro unmanned aerial vehicle (UAV) developed by Prox Dynamics AS of Norway, and in use by the Norwegian and British Army.

The unit measures around 10 × 2.5 cm (4 × 1 in) and provides troops on the ground with local situational awareness. They are small enough to fit in one hand and weigh just over half an ounce (16 g, including batteries).

The UAV is equipped with a camera, which gives the operator full-motion video and still images. They were developed as part of a £20 million contract for 160 units with Marlborough Communications Ltd.

The Marine Corps Warfighting Laboratory is interested in the PD-100 Black Hornet, a small unmanned aircraft that can capture full-motion video and thermal images in real time. 
Photo: Prox Dynamics image

The Marine Corps Warfighting Laboratory's Unmanned Tactical Autonomous Control and Collaboration (UTACC) leverages advanced robotics and autonomy to minimize operator workload – putting the Marine back into the fight. UTACC is a team of autonomous air and ground robots that provides multi-dimensional ISR to the squad level of operations. 
The end state of the UTACC is to enhance infantry squad missions accomplishment while simultaneously reducing the cognitive load on the operator. The Marine Corps Warfighting Laboratory is conducting the second Limited Technical Assessment on the UTACC later this month as part of its continued exploration of Manned Unmanned Teaming (MUMT).

The Marine Corps Warfighting Laboratory is also evaluating the Modular Advanced Armed Robotic System, a tracked vehicle with several sensors and armed with a M240B machine gun.
Photo: Courtesy of QinetiQ

The U.S. Naval Laboratory is developing CICADA,  a concept for a low-cost, GPS-guided, micro disposable air vehicle that can be deployed in large numbers to "seed" an area with miniature electronic payloads. These payloads could be interconnected to form an ad-hoc, self-configuring network. Communication nodes, sensors, or effectors can then be placed in a programmable geometric pattern in hostile territory without directly over-flying those regions or exposing human agents on the ground.

Essentially a flying circuit board, CICADA has an extremely high packing factor and a very low per-unit cost. Eighteen vehicles can be contained in a six-inch cube. The vehicle is inherently stable in glide, with a glide ratio of 3.5.

Once released (as in this depiction, from a C-130) CICADA gliders are virtually undetectable. The U.S. Naval Research Laboratory (NRL) invented CICADA and demonstrated it can fly to a precise waypoint and deliver a payload. CICADA will be featured as part of the Department of Defense Lab Day at the Pentagon on May 14, 2015. 
Photo: U.S. Naval Research Laboratory




Contacts and sources:
Leah Burrows
Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS)
U.S. Naval Research Laboratory (NRL)
The Marine Corps Warfighting Laboratory

Great Dying in the Oceans Coming: Loss of Oxygen Suffocating Marine Life, Dismal Predictions for 2030-2040

A disturbing prediction by scientists is reminiscent of "Soylent Green," a 1973 film depicting a dystopian future suffering from pollution, overpopulation, depleted resources, poverty, dying oceans, and year-round humidity due to the greenhouse effect.  

Climate change has caused a drop in the amount of oxygen dissolved in the oceans in some parts of the world, and those effects should become evident across large parts of the ocean between 2030 and 2040, according to a new study led by researchers at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado.

In ocean waters with less oxygen, fish kills are common.
Credit: NOAA

Scientists expected a warming climate to sap oceans of oxygen, leaving fish, crabs, squid, sea stars, and other marine life struggling to breathe. But they had encountered difficulties in determining whether this anticipated oxygen drain was already having a noticeable effect.

By the 2030s, declining oxygen levels will likely be evident in many of the world's oceans.
Credit: NCAR

"Loss of oxygen in the oceans is one of the serious side effects of a warming atmosphere, and a major threat to marine life," said NCAR scientist Matthew Long, lead author of the study. “Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the effect from climate change to overwhelm the natural variability."

The study is published in the American Geophysical Union journal Global Biogeochemical Cycles. The research was funded by the National Science Foundation (NSF).

Cutting through the natural variability

The entire ocean -- from the depths to the shallows -- gets its oxygen supply from the surface, either from the atmosphere or from phytoplankton, which release oxygen into the water through photosynthesis.

Warming surface waters, however, absorb less oxygen. And, in a double whammy, the absorbed oxygen has a more difficult time traveling deeper into the ocean. That's because as water heats up, it expands, becoming lighter than the water below it and less likely to sink.

Marine life moves much more slowly in a low-oxygen ocean.

Credit: NOAA

Thanks to natural warming and cooling, oxygen concentrations at the sea's surface change constantly -- and deeper in the ocean, those changes can linger for years or decades.

For example, an exceptionally cold winter in the North Pacific would allow the ocean surface to soak up a large amount of oxygen. Thanks to the natural circulation pattern, that oxygen would then be carried deeper into the ocean, where it might still be detectable years later as it travels along its flow path.

On the flip side, unusually hot weather could lead to "dead zones" in the ocean, where fish and other marine life cannot survive.

To cut through this natural variability and investigate the impact of climate change, the research team -- including Curtis Deutsch of the University of Washington and Taka Ito of Georgia Tech -- relied on the NCAR-based Community Earth System Model, which is funded by NSF and the U.S. Department of Energy.

“This study shows how far comprehensive Earth System Models have come in the effort to quantify, along with relatively sparse observations, large-scale changes in oxygen in the oceans due to both natural variability and climate change,” said Eric Itsweire, program director in NSF's Division of Ocean Sciences.

The scientists used output from a project that ran the model more than two dozen times for the years 1920 to 2100. Each individual run started with miniscule variations in air temperature. As the model runs progressed, those tiny differences grew and expanded, producing a set of climate simulations useful for studying questions about variability and change.

Dungeness crabs washed up on a beach in Oregon after suffocating in low-oxygen waters.

Credit: Elizabeth Gates, courtesy of PISCO

Using the simulations to study dissolved oxygen gave the researchers guidance on the degree to which concentrations may have varied naturally in the past. With this information, they could determine when ocean deoxygenation due to climate change is likely to become more severe than at any point in the modeled historic range.

The researchers found they could already detect deoxygenation caused by climate change in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins.

They also determined that more widespread detection of deoxygenation caused by climate change would be possible between 2030 and 2040.

However, in some parts of the ocean, including areas off the east coasts of Africa, Australia, and Southeast Asia, deoxygenation caused by climate change would not become evident even by 2100.

Detecting a global pattern

The researchers also created a visual way to distinguish between deoxygenation caused by natural processes and deoxygenation caused by climate change.

Using the same model dataset, the scientists created maps of oxygen levels in the ocean, showing which waters were oxygen-rich and which were oxygen-poor. They found they could distinguish between oxygenation patterns caused by natural weather phenomena and the pattern caused by climate change.


Declining cod stocks may be further threatened by waters with low oxygen.

Credit: NOAA

The climate change pattern also became evident in the model runs around 2030, adding confidence to the conclusion that widespread deoxygenation due to climate change will become detectable around that time.

The maps could also be useful resources for deciding where to place instruments to monitor ocean oxygen levels in the future to get the best picture of climate change effects. Currently, ocean oxygen measurements are relatively sparse.

"We need comprehensive and sustained observations of what's going on in the oceans to compare with what we're learning from our models, and to understand the full effect of a changing climate," Long said.

In the movie,  most of the population survived on rations produced by the Soylent Corporation, whose newest product is Soylent Green, a green wafer advertised to contain "high-energy plankton" from the world's oceans, but the Oceans are found to be dying.  Soylent's oceanographic reports reveal that the oceans no longer produce the plankton from which Soylent Green is reputedly made, and infer that it is made from human remains, the only conceivable supply of protein matching the known production.


The film took place in 2022 and predicted 40 million people in New York City,  living in dilapidated and overcrowded housing; homeless people fill the streets; many are unemployed, the few "lucky" ones with jobs are only barely scraping by, and food and working technology is scarce.  

The 2015 population of the 5 boroughs was 8,550,405 but the New York Metro area is home to 17.8 million. Tokyo/Yokohama is currently the world's most populated city with more than 33 million residents.    

10 Largest cities in the world ranked by population 

 Rank
City / Urban area
Country
Population
Land area
(in sqKm)
Density
(people per sqKm)
1
Tokyo/YokohamaJapan
33,200,000
6,993
4,750
2
New York MetroUSA
17,800,000
8,683
2,050
3
Sao PauloBrazil
17,700,000
1,968
9,000
4
Seoul/IncheonSouth Korea
17,500,000
1,049
16,700
5
Mexico CityMexico
17,400,000
2,072
8,400
6
Osaka/Kobe/KyotoJapan
16,425,000
2,564
6,400
7
ManilaPhilippines
14,750,000
1,399
10,550
8
MumbaiIndia
14,350,000
484
29,650
9
DelhiIndia
14,300,000
1,295
11,050
10
JakartaIndonesia
14,250,000
1,360
10,500






Contacts and source: 
David Hosansky, National Center for Atmospheric Research
Cheryl Dybas, NSF

Tuesday, May 24, 2016

Unstable East Antarctic Glacier Contributed To Several Sea Level Rises In The Past

Research published in the journal Nature on May 19 has revealed that vast regions of the Totten Glacier in East Antarctica are fundamentally unstable and have contributed significantly to rising sea levels several times in the past.

Totten Glacier is the most rapidly thinning glacier in East Antarctica, and this study raises concerns that a repeat transition between stable and unstable states could be underway as the climate warms.

Totten Glacier's ice shelf. 

Credit: Jamin Greenbaum, The University of Texas Institute for Geophysics.

An international consortium led by The University of Texas at Austin’s Institute for Geophysics (UTIG), a unit at the university’s Jackson School of Geosciences, led the research and data collection for the study. Alan Aitken of the University of Western Australia’s School of Earth and Environment is the lead author.

Totten Glacier is East Antarctica’s largest outlet of ice and a key region for understanding the large-scale and long-term vulnerabilities of the Antarctic Ice Sheet. Until now, knowledge of the region's glacial history has been very limited. Whereas other studies have indicated that this region of the ice sheet may have retreated in the past, this study reveals direct linkages between the modern Totten Glacier and the eroded landscape currently buried in ice hundreds of kilometers inland.

“We now know how the ice sheet evolves over the landscape in East Antarctica and where it is susceptible to rapid retreat, which gives us insight into what is likely to happen in the years ahead,” said Donald D. Blankenship, lead principal investigator of ICECAP (International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling) and a senior research scientist at UTIG.

Totten Glacier’s catchment is a collection basin for ice and snow that flows through the glacier.

“Totten Glacier’s catchment is covered by nearly 2½ miles of ice, filling a California-sized sub-ice basin that reaches depths of over one mile below sea level,” Blankenship said. “This study shows that this system could have a large impact on sea level in a short period of time.”

The UTIG-led ICECAP project collected the data during five Antarctic field campaigns using an aircraft equipped with instruments to assess the ice and measure the shape of the landscape and rocks beneath it. The airplane was outfitted with radar that can measure ice several miles thick, lasers to measure the shape and elevation of the ice surface, and equipment that senses Earth’s gravity and magnetic field strengths, which are used to infer the sub-ice geology.

The study used ice-penetrating radar, magnetic and gravity data to determine the thickness of the ice sheet and the sediment thickness under the ice sheet. These were used to map glacial erosion beneath the ice and find two unstable zones where the ice sheet is prone to rapid collapse.

“By examining the characteristic patterns of erosion left by past ice sheet advance and retreat, revealed through mapping the topographic surface and the thickness of sedimentary rocks beneath, this paper demonstrates direct evidence of past changes in the ice sheet in the Totten region,” Aitken said.

The study found the transition between the stable and unstable states has occurred repeatedly during the life of the ice sheet.

Totten Glacier, East Antarctica's largest outlet of ice, is unstable and has contributed significantly to rising seas levels in the past, according to new research.

Credit: The University of Texas at Austin

“If this was to happen again, with a warmer climate than today, it could lead to a rapid rise in sea level of over a meter,” Aitken said.

ICECAP is a long-term international collaboration among the United States, Australia, the United Kingdom and France. The data for this study were gathered with the support of the U.K.’s Natural Environment Research Council, the U.S. National Science Foundation and the Australian Antarctic Division, as well as NASA’s Operation IceBridge, the G. Unger Vetlesen Foundation, and UT Austin’s Jackson School of Geosciences. The ICECAP aircraft was operated under contract to UTIG by Kenn Borek Air Ltd., Calgary, Alberta, Canada.



Contacts and sources: 
Anton Caputo
The University of Texas at Austin

Mars and Saturn at Opposition

Mars and Saturn are getting together in the constellation Scorpius for back-to-back oppositions in May and June 2016.

Star Paradox: Solar Storms May Have Been Key to Life on Earth

Our sun's adolescence was stormy—and new evidence shows that these tempests may have been just the key to seeding life as we know it.

Some 4 billion years ago, the sun shone with only about three-quarters the brightness we see today, but its surface roiled with giant eruptions spewing enormous amounts of solar material and radiation out into space. These powerful solar explosions may have provided the crucial energy needed to warm Earth, despite the sun's faintness.

Artist concept of our sun 4 billion years ago.

Credit: NASA/GSFC/CIL

The eruptions also may have furnished the energy needed to turn simple molecules into the complex molecules such as RNA and DNA that were necessary for life. The research was published in Nature Geoscience on May 23, 2016, by a team of scientists from NASA.

Watch this movie to see how energy from our young sun – 4 billion years ago -- aided in creating molecules in Earth's atmosphere that allowed it to warm up enough to incubate life.

Credits: NASA's Goddard Space Flight Center/Genna Duberstein
Download this video in HD formats from NASA Goddard's Scientific Visualization Studio

Understanding what conditions were necessary for life on our planet helps us both trace the origins of life on Earth and guide the search for life on other planets. Until now, however, fully mapping Earth's evolution has been hindered by the simple fact that the young sun wasn't luminous enough to warm Earth.

"Back then, Earth received only about 70 percent of the energy from the sun than it does today," said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "That means Earth should have been an icy ball. Instead, geological evidence says it was a warm globe with liquid water. We call this the Faint Young Sun Paradox. Our new research shows that solar storms could have been central to warming Earth."

Artist concept of the Earth 4 billion years ago. 
Credit: NASA/GSFC/CIL
Scientists are able to piece together the history of the sun by searching for similar stars in our galaxy. By placing these sun-like stars in order according to their age, the stars appear as a functional timeline of how our own sun evolved. It is from this kind of data that scientists know the sun was fainter 4 billion years ago. Such studies also show that young stars frequently produce powerful flares – giant bursts of light and radiation -- similar to the flares we see on our own sun today. Such flares are often accompanied by huge clouds of solar material, called coronal mass ejections, or CMEs, which erupt out into space.

NASA's Kepler mission found stars that resemble our sun about a few million years after its birth. The Kepler data showed many examples of what are called "superflares" – enormous explosions so rare today that we only experience them once every 100 years or so. Yet the Kepler data also show these youngsters producing as many as ten superflares a day.

While our sun still produces flares and CMEs, they are not so frequent or intense. What's more, Earth today has a strong magnetic field that helps keep the bulk of the energy from such space weather from reaching Earth. Space weather can, however, significantly disturb a magnetic bubble around our planet, the magnetosphere, a phenomenon referred to as geomagnetic storms that can affect radio communications and our satellites in space. It also creates auroras – most often in a narrow region near the poles where Earth's magnetic fields bow down to touch the planet.

Our young Earth, however, had a weaker magnetic field, with a much wider footprint near the poles.

"Our calculations show that you would have regularly seen auroras all the way down in South Carolina," says Airapetian. "And as the particles from the space weather traveled down the magnetic field lines, they would have slammed into abundant nitrogen molecules in the atmosphere. Changing the atmosphere's chemistry turns out to have made all the difference for life on Earth."

Artist concept of the Earth's weak early magnetosphere being impacted by a coronal mass ejection 4 billion years ago. 

Credit: NASA/GSFC/CIL

The atmosphere of early Earth was also different than it is now: Molecular nitrogen – that is, two nitrogen atoms bound together into a molecule – made up 90 percent of the atmosphere, compared to only 78 percent today. As energetic particles slammed into these nitrogen molecules, the impact broke them up into individual nitrogen atoms. They, in turn, collided with carbon dioxide, separating those molecules into carbon monoxide and oxygen.

The free-floating nitrogen and oxygen combined into nitrous oxide, which is a powerful greenhouse gas. When it comes to warming the atmosphere, nitrous oxide is some 300 times more powerful than carbon dioxide. The teams’ calculations show that if the early atmosphere housed less than one percent as much nitrous oxide as it did carbon dioxide, it would warm the planet enough for liquid water to exist.

This newly discovered constant influx of solar particles to early Earth may have done more than just warm the atmosphere, it may also have provided the energy needed to make complex chemicals. In a planet scattered evenly with simple molecules, it takes a huge amount of incoming energy to create the complex molecules such as RNA and DNA that eventually seeded life.

While enough energy appears to be hugely important for a growing planet, too much would also be an issue -- a constant chain of solar eruptions producing showers of particle radiation can be quite detrimental. Such an onslaught of magnetic clouds can rip off a planet's atmosphere if the magnetosphere is too weak. Understanding these kinds of balances help scientists determine what kinds of stars and what kinds of planets could be hospitable for life.

"We want to gather all this information together, how close a planet is to the star, how energetic the star is, how strong the planet's magnetosphere is in order to help search for habitable planets around stars near our own and throughout the galaxy," said William Danchi, principal investigator of the project at Goddard and a co-author on the paper. "This work includes scientists from many fields -- those who study the sun, the stars, the planets, chemistry and biology. Working together we can create a robust description of what the early days of our home planet looked like – and where life might exist elsewhere."



Contacts and sources:
By Karen C. Fox
NASA's Goddard Space Flight Center

For more information about the Kepler mission, visit: http://www.nasa.gov/kepler

Single Virus Found Fast in Urine: Heralds Easy Detection Method for Ebola, Zika and HIV

Scientists at The University of Texas at Austin have developed a new method to rapidly detect a single virus in urine, as reported this week in the journal Proceedings of the National Academy of Sciences.

Viruses are microscopic; they range in size from about 20 to 400 nanometers in diameter (1 nanometer = 10-9 meters) and are only seen through the most powerful microscopes.

While the technique presently works on just one virus, scientists say it could be adapted to detect a range of viruses that plague humans, including Ebola, Zika and HIV.


Color-enhanced electron micrograph of Ebola virus particles
Thomas W. Geisbert, Boston University School of Medicine - PLoS Pathogens, November 2008

"The ultimate goal is to build a cheap, easy-to-use device to take into the field and measure the presence of a virus like Ebola in people on the spot," says Jeffrey Dick, chemistry graduate student and co-lead author of the study. "While we are still pretty far from this, this work is a leap in the right direction."

The other co-lead author is Adam Hilterbrand, a microbiology graduate student.

The new method is highly selective, meaning it is only sensitive to one type of virus, filtering out possible false negatives due to other viruses or contaminants.

There are two other commonly used methods for detecting viruses in biological samples, but they have drawbacks: one requires a much higher concentration of viruses and the other requires samples to be purified to remove contaminants. The new method, however, can be used with urine straight from a person or animal.

The other co-authors are Lauren Strawsine, a postdoctoral fellow in chemistry, Jason Upton, an assistant professor of molecular biosciences and Allen Bard, professor of chemistry and director of the Center for Electrochemistry.

The researchers demonstrated their new technique on a virus that belongs to the same family as the herpes virus, called murine cytomegalovirus (MCMV). To detect individual viruses, the team places an electrode--a wire that conducts electricity, in this case, one that is thinner than a human cell--in a sample of mouse urine. They then add to the urine some special molecules made up of enzymes and antibodies that naturally stick to the virus of interest. When all three stick together and then bump into the electrode, there's a spike in electric current that can be easily detected.

Various viruses from the Herpesviridae family seen using an electron micrograph Amongst these members is varicella-zoster (Chickenpox), and herpes simplex type 1 and 2 (HSV-1, HSV-2).
Herpesviridae EM PHIL 2171 lores.jpg
 Photo Credit: Content Providers: CDC/ E. L. Palmer - This media comes from the Centers for Disease Control and Prevention's Public Health Image Library

The researchers say their new method still needs refinement. For example, the electrodes become less sensitive over time because a host of other naturally occurring compounds stick to them, leaving less surface area for viruses to interact with them. To be practical, the process will also need to be engineered into a compact and rugged device that can operate in a range of real world environments.



Contacts and sources: 
Marc Airhart
University of Texas Austin

Man-Eating Monster Nile Crocodiles Invade Florida

DNA discovery points to an unexpected African invasion in the Sunshine State. 

Spotting native alligators and crocodiles in Florida is common, but anyone who sees a large reptile may want to take a second look-- man-eaters that can grow to 18 feet long and weigh as much as a small car have been found in the Sunshine State.

Using DNA analysis, University of Florida researchers have confirmed the capture of multiple Nile crocodiles in the wild.

The ancient icon eats everything from zebras to small hippos to humans in sub-Saharan Africa. Now three juveniles of the monster crocodile, have been found in South Florida, swimming in the Everglades and relaxing on a house porch in Miami.

Nile crocodiles 
File:Djerba Explore Nile Crocodiles eating 16.JPG
Credit: Ad Meskens.

The invasive crocodiles were captured between 2000 and 2014, leading UF scientists to analyze their DNA, study their diet and one of the animal's growth. Scientists verified the animals were Nile crocodiles linked to native populations in South Africa, and confirmed the species can survive in Florida -- and potentially thrive, said Kenneth Krysko, herpetology collections manager at the Florida Museum of Natural History on the UF campus.

In other words, there likely are more.

"The odds that the few of us who study Florida reptiles have found all of the Nile crocs out there is probably unlikely," said Krysko, co-author of the study published in April in the Journal of Herpetological Conservation and Biology. "We know that they can survive in the Florida wilderness for numerous years, we know that they grow quickly here and we know their behavior in their native range, and there is no reason to suggest that would change here in Florida."

Nile crocodiles, Crocodylus niloticus, were responsible for at least 480 attacks on people and 123 fatalities in Africa between 2010 and 2014. They are generalist predators and eat a wide variety of prey. In Florida, everything from native birds, fish and mammals to the state's native crocodile and alligator would be fair game for the carnivorous croc.

The study found one juvenile grew nearly 28 percent faster than wild Nile crocodile juveniles from some parts of their native range.

DNA analysis revealed the three similar-size Nile crocodiles were genetically identical, suggesting they were introduced via the same source, but Krysko said the source has not been confirmed. Prior to graduating in 2013, former UF doctoral student and co-author Matthew Shirley extensively sampled DNA of live Nile crocodiles housed in U.S. zoos, including Florida. The DNA of the three crocodiles did not match any of those Shirley sampled, suggesting they were either acquired by a permitted source later, or introduced by someone without a permit.

Study scientists note that over the last decade, large groups of Nile crocodiles have been imported from South Africa and Madagascar for display at places like Disney's Animal Kingdom and to supply Florida's flourishing pet trade, with the latter being the most likely introduction pathway, according to the study.

While there is currently no evidence of an established population, study scientists recommend a scientific risk assessment to evaluate the potential for Nile crocodiles to breed and spread across the state. According to the study, Florida's Atlantic coast and the entire Gulf of Mexico coastline provide favorable climate for Nile crocodiles.

Florida's subtropical climate is one reason the state has the world's largest number of invasive species -- from the Burmese python that has invested the Everglades to the Cuban tree frog, which has been found as far north as Jacksonville on the East Coast and as far north as Cedar Key on the Gulf Coast.

"My hope as a biologist is that the introduction of Nile crocodiles in Florida opens everyone's eyes to the problem of invasive species that we have here in our state," Krysko said. "Now here's another one, but this time it isn't just a tiny house gecko from Africa."

A large adult American alligator's weight and length is 800 pounds (360 kg) and 13 feet (4.0 m) long, but can grow to 14.5 feet (4.4 m) long and weigh over 1,000 pounds (450 kg). The largest ever recorded was found in Louisiana and measured 19 feet 2 inches (5.84 m). The Chinese alligator is smaller, rarely exceeding 7 feet (2.1 m) in length. Alligators have an average of 75 teeth. Alligators are only native to the United States and China.

American Alligator
File:American Alligator.JPG

American alligators are found in the southeast United States: all of Florida and Louisiana, the southern parts of Georgia, Alabama and Mississippi, coastal South and North Carolina, Eastern Texas, the southeast corner of Oklahoma and the southern tip of Arkansas. According to the 2005 Scholastic Book of World Records, Louisiana is the state with the largest alligator population. The majority of American alligators inhabit Florida and Louisiana, with over a million alligators in each state.



Contacts and sources:
Writer: Stephenie Livingston
Frank Mazzotti
Kenneth Krysko
University of Florida

"Young" Craters Found on the Moon and Collision History

A Southwest Research Institute-led team of scientists discovered two geologically young craters -- one 16 million, the other between 75 and 420 million, years old -- in the Moon's darkest regions.  A new technique allows scientists to 'age' craters in the darkest regions of the Moon. 

"These 'young' impact craters are a really exciting discovery," said SwRI Senior Research Scientist Dr. Kathleen Mandt, who outlined the findings in a paper published by the journalIcarus. "Finding geologically young craters and honing in on their age helps us understand the collision history in the solar system."

Using data from the LAMP instrument aboard the Lunar Reconnaissance Orbiter, a Southwest Research Institute-led team of scientists discovered two geologically young craters — one (right) 16 million, the other (left) between 75 and 420 million, years old — in the Moon’s darkest regions. One lies within Slater Crater, named for the late Dr. David C. Slater, a former SwRI space scientist who designed and built the LAMP instrument.

Albedo map credit: NASA GSFC/SwRI
Topographic map credit: NASA GSFC/ASU Jmoon

Key to this discovery was the SwRI-developed Lyman-Alpha Mapping Project (LAMP) instrument aboard the Lunar Reconnaissance Orbiter (LRO). LAMP uses the far-ultraviolet Lyman-alpha band skyglow and light from ultraviolet-bright stars LAMP to "see" in the dark and image the permanently shaded regions of the Moon. Using LAMP and LRO's Mini-RF radar data, the team mapped the floors of very large, deep craters near the lunar south pole. These deep craters are difficult to study because sunlight never illuminates them directly. Tiny differences in reflectivity, or albedo, measured by LAMP allowed scientists to discover these two craters and estimate their ages.

"We study planetary geology to understand the history of solar system formation," said SwRI's Dr. Thomas Greathouse, LAMP deputy principal investigator. "It is exciting and extremely gratifying to happen upon a unique and unexpected new method for the detection and age determination of young craters in the course of nominal operations."

Collisions in space have played an important role in the formation of the solar system, including the formation of the Moon. Impact craters tell the history of collisions between objects in the solar system.

Because the Moon has been peppered with impacts, its surface serves as a record of its past. Determining when collisions occurred helps scientists map the motion of objects in the solar system throughout its history. Craters that are young on geological timescales (millions of years) also provide information on the frequency of collisions.

When a small object collides with a larger object, such as the Moon, the impact creates a crater on the larger body. Craters can be a few feet in diameter or several miles wide. During the impact, the material ejected forms a blanket of material surrounding the crater. The ejecta blankets of "fresh," relatively young craters have rough surfaces of rubble and a sprinkling of condensed, bright dust. Over millions of years, these features undergo weathering and become covered with layers of fluffy, dark dust.

Scientists determined that the areas around the two craters were brighter and rougher than the surrounding landscape. The team estimated the age of one crater at about 16 million years. The other crater's rough extended ejecta blanket had faded, showing that this crater must be at least 75 million years old. But time would have completely covered the ejecta blanket in fluffy dust within 420 million years, providing an upper limit on its age. Other images, produced using laser altimetry and sunlight scattered off crater walls, provided details about topography, surface features, and material properties.

"Discovering these two craters and a new way to detect young craters in the most mysterious regions of the Moon is particularly exciting," said Mandt. "This method will be useful not only on the Moon, but also on other interesting bodies, including Mercury, the dwarf planet Ceres, and the asteroid Vesta."

 

Contacts and sources:
Deb Schmid
Southwest Research Institute

Citation: "LRO-LAMP Detection of Geologically Young Craters within Lunar Permanently Shaded Regions" is published in Icarus (2016), http://dx.doi.org/10.1016/j.icarus.2015.07.031. This work was funded by NASA's Lunar Reconnaissance Orbiter project.

The Universe As It Was 13 Billion Years Ago

The magicians of science have looked further back into time than any others have done to this point in time to plumb the great mysteries of our creation. 

In 2012, WMAP estimated the age of the universe to be 13.772 billion years, with an uncertainty of 59 million years. In 2013, Planck measured the age of the universe at 13.82 billion years.

An international team of scientists, including two professors and three graduate students from UCLA, has detected and confirmed the faintest early-universe galaxy ever. Using the W. M. Keck Observatory on the summit on Mauna Kea in Hawaii, the researchers detected the galaxy as it was 13 billion years ago. The results were published in theAstrophysical Journal Letters.

Tommaso Treu, a professor of physics and astronomy in the UCLA College and a co-author of the research, said the discovery could be a step toward unraveling one of the biggest mysteries in astronomy: how a period known as the "cosmic dark ages" ended.

Galaxy cluster: Composite image of the galaxy cluster from three different filters on the Hubble Space Telescope. The wave charts (insets at left) show spectra of the multiply imaged systems. The fact that they share peaks at the same wavelength shows that they belong to the same source. At bottom right, the Keck I and Keck II Telescopes at Hawaii’s the W. M. Keck Observatory.
Credit: BRADAC/HST/W. M. Keck Observatory

The researchers made the discovery using an effect called gravitational lensing to see the incredibly faint object, which was born just after the Big Bang. Gravitational lensing was first predicted by Albert Einstein almost a century ago; the effect is similar to that of an image behind a glass lens appearing distorted because of how the lens bends light.

The detected galaxy was behind a galaxy cluster known as MACS2129.4-0741, which is massive enough to create three different images of the galaxy.

According to the Big Bang theory, the universe cooled as it expanded. As that happened, Treu said, protons captured electrons to form hydrogen atoms, which in turn made the universe opaque to radiation -- giving rise to the cosmic dark ages.

A representation of the evolution of the universe over 13.77 billion years. The far left depicts the earliest moment we can now probe, when a period of "inflation" produced a burst of exponential growth in the universe. (Size is depicted by the vertical extent of the grid in this graphic.) For the next several billion years, the expansion of the universe gradually slowed down as the matter in the universe pulled on itself via gravity. 
More recently, the expansion has begun to speed up again as the repulsive effects of dark energy have come to dominate the expansion of the universe. The afterglow light seen by WMAP was emitted about 375,000 years after inflation and has traversed the universe largely unimpeded since then. The conditions of earlier times are imprinted on this light; it also forms a backlight for later developments of the universe.

"At some point, a few hundred million years later, the first stars formed and they started to produce ultraviolet light capable of ionizing hydrogen," Treu said. "Eventually, when there were enough stars, they might have been able to ionize all of the intergalactic hydrogen and create the universe as we see it now."

That process, called cosmic reionization, happened about 13 billion years ago, but scientists have so far been unable to determine whether there were enough stars to do it or whether more exotic sources, like gas falling onto supermassive black holes, might have been responsible.

The detailed, all-sky picture of the infant universe created from nine years of WMAP data. The image reveals 13.77 billion year old temperature fluctuations (shown as color differences) that correspond to the seeds that grew to become the galaxies. The signal from the our Galaxy was subtracted using the multi-frequency data. This image shows a temperature range of ± 200 microKelvin.

Credit: NASA / WMAP Science Team

"Currently, the most likely suspect is stars within faint galaxies that are too faint to see with our telescopes without gravitational lensing magnification," Treu said. "This study exploits gravitational lensing to demonstrate that such galaxies exist, and is thus an important step toward solving this mystery."

The research team was led by Marusa Bradac, a professor at UC Davis. Co-authors include Matthew Malkan, a UCLA professor of physics and astronomy, and UCLA graduate students Charlotte Mason, Takahiro Morishita and Xin Wang.

The galaxy's magnified spectra were detected independently by both Keck Observatory and Hubble Space Telescope data.


Contacts and sources:
Stuart Wolpert
UCLA