IRIS: New NASA Spacecraft to Study Mysterious Region of Sun’s Atmosphere
NASA’s Interface Region Imaging Spectrograph (IRIS) with solar panels open in flight position, in the clean room at the Lockheed Martin Advanced Technology Center in Palo Alto, where it was designed and built. (LMSAL)
Did you know that the Sun’s outer atmosphere, or corona, is much hotter than its surface? Scientists have been quite curious about a mysterious interface region of the Sun’s atmosphere that amplifies energy from about 5,800 degrees Kelvin on the surface, or photosphere, to around 1,000,000 degrees Kelvin in the corona.
According to NASA, most of the sun’s ultraviolet radiation, which they say has an impact on Earth’s climate, is also produced in this interface region.
This image from Japan Aerospace Exploration Agency’s (JAXA) Hinode mission shows the lower regions of the sun’s atmosphere, the interface region, which the Interface Region Imaging Spectrograph, or IRIS, will study in detail. (Photo: JAXA/Hinode)
“We are thrilled to add IRIS to the suite of NASA missions studying the sun,” said John Grunsfeld, NASA’s associate administrator for science in Washington. “IRIS will help scientists understand the mysterious and energetic interface between the surface and corona of the sun.”
At 6:30PM Thursday, an Orbital L-1011 carrier aircraft, with the Pegasus XL rocket and its IRIS spacecraft payload strapped beneath, it took off from California’s Vandenberg Air Force base to a release site over the Pacific Ocean.
Five seconds after being dropped by the plane, the first stage of the Pegasus XL ignited and carried IRIS into space. NASA officials said that the IRIS spacecraft successfully separated from its launch rocket’s third stage at 7:40 PM PDT. Twenty-five minutes later, at 8:05 PM PDT, the IRIS team received confirmation that the spacecraft successfully deployed its solar arrays (seen in the top photo), had power, acquired its target, the sun, and that all systems were operating as expected.
NASA Video of the release and launch of the Pegasus XL from its Orbital L-1011 carrier aircraft
NASA says the IRIS is now going through what it calls a 60-day commissioning phase to make sure the spacecraft and its onboard instruments are functioning properly.
Mission leaders say that they are centering IRIS’ science investigation on three main themes.
The Sun’s corona, or atmosphere, taken with a special camera that blocks out light from the Sun’s main disk. (ESA/NASA/SOHO)
1. Which types of non-thermal energy dominate in the Sun’s chromosphere and beyond?
2. How does the chromosphere regulate mass and energy supply the corona and heliosphere, which NASA says is the giant magnetic bubble that extends way beyond the orbit of Pluto and contains our solar system, the solar wind, and the entire solar magnetic field?
3. How do magnetic flux, the flow of magnetic energy, and matter rise through the lower atmosphere, and what role does flux emergence play in flares and mass ejections?
After its launch, IRIS was placed in a sun-synchronous polar orbit where it will circle over the north and south poles and pass over the same part of Earth at about the same time of day. This unique orbit will allow the IRIS mission team to make almost continuous solar observations during its planned two-year mission.
Study: Diet Changes May Have Been Crucial Step in Becoming Human
Illustration of Paranthropus hominid in southern Africa one million years ago. (Artwork by Walter Voigt -provided by Lee Berger and Brett Hilton-Barber)
A change in diet about 3.5 million years ago may have set hominid species on a path to becoming human, according to a study led by the University of Colorado, Boulder.
Grasses and sedges were readily available back then, but the hominids seem to have ignored them for an extended period, said anthropology Professor Matt Sponheimer, lead author of the study.
“We don’t know exactly what happened,” said Sponheimer. “But we do know that after about 3.5 million years ago, some of these hominids started to eat things that they did not eat before, and it is quite possible that these changes in diet were an important step in becoming human.”
A field of grass-like sedge in Hamerkop Kloof, Magaliesberg, South Africa (Wikimedia Commons)
Scientists had previously analyzed the teeth of about 87 ancient hominid specimens. Sponheimer and his team came up with new detailed information on the teeth of 88 additional specimens, which also included five previously unanalyzed hominid species.
To find out what kind of plants these early hominids ate, Sponheimer’s team analyzed the carbon isotopes found on the fossilized teeth. The researchers found the carbon signals of two distinct plant groups; the first, called C3, came from plants like trees and bushes, while the other, called C4, came from plants like grasses and sedges, which are flowering grasses.
The researchers also examined the microscopic wear of hominid teeth, which provided scientists with more information on the foods they were eating. Since there were multiple species of hominids, there was no such thing as one specific hominid diet.
The skull of Paranthropus boisei photographed at the Nairobi National Museum (Bjørn Christian Tørrissen via Wikimedia Commons)
While early ancestors in the genus Homo, which includes modern humans and the 3 million-year-old fossil known as Lucy – who many scientists see as the matriarch of today’s humans – were diversifying their diets with different food choices, another type of short, upright hominid, the Paranthropus boisei, who also lived in Eastern Africa at the time, was moving toward a much more specific diet made up mostly of items like the grasses.
Scientists had given the P. boisei hominids the nickname “Nutcracker Man” because it had large, flat teeth and powerful jaws that may have been powerful enough to crack nuts. But, according to Sponheimer, more recent analyses suggest they might have actually used their back teeth to grind grasses and sedges.
“We now have the first direct evidence that, as the cheek teeth on hominids got bigger, their consumption of plants like grasses and sedges increased,” he said. “We also see niche differentiation between Homo and Paranthropus. It looks probable that Paranthropus boisei had a relatively restricted diet, while members of the genus Homo were eating a wider variety of things. The genus Paranthropus went extinct about one million years ago, while the genus Homo, that includes us, obviously did not.”
Researchers are puzzled at the differences in the evolution of those hominids living in eastern Africa compared to those from southern Africa.
Another hominid, called Paranthropus robustus, which was found in southern Africa was very anatomically similar its eastern African cousin, P. boisei. But Sponheimer and his team found that the teeth of the two had quite different carbon isotopic compositions in their teeth, which suggested that they each ate different diets.
Artist representation of Paranthropus in southern Africa more than one million years ago. (Courtesy ArchaeologyInfo.com/ScottBjelland)
The southern African P. robustus hominid appeared to have augmented its diet of grasses and sedges with items from the C3 group such as trees and bushes.
“This has probably been one of the biggest surprises to us so far,” said Sponheimer. “We had generally assumed that the Paranthropus species were just variants on the same ecological theme, and that their diets would probably not differ more than those of two closely related monkeys in the same forest.
But the researchers found that their isotopic evidence of each of the hominids indicated that their diets were so different from each other that they could have been as different as primate diets can be.
“Ancient fossils don’t always reveal what we think they will. The upside of this disconnect is that it can teach us a great deal, including the need for caution in making pronouncements about the diets of long-dead critters,” said Sponheimer.
Science Images of the Week
NASA’s spectacular 1.3 billion pixel image, taken by the Curiosity Mars Rover, shows Curiosity at the Rocknest site, where it scooped up samples of windblown dust and sand. This is a reduced version of the original panorama. Click on photo to see full version. (NASA)
Three mouse lemurs (Microcebus murinus) peer cautiously from their nesting tube. Personality research from the Duke Lemur Center found some mouse lemurs are shy, while others were actually bold. (David Haring, Duke Lemur Center)
University of Miami researchers film at Dean’s Blue Hole in the Bahamas, the world’s deepest known blue hole or underwater sinkhole that drops to a depth of 202 meters. (Patrick Rynne)
Scientists from the University of Washington, studying in South America, have found that seeds of the wild chili pepper have a better chance of surviving and becoming a new plant if first swallowed and then expelled by a bird. Here’s an ant carrying a wild chili pepper seed that made its trip by and through a bird. (Thomas Carlo)
The Sculptor galaxy, located in the constellation Sculptor, is seen in a new composite image from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Southern Observatory in Chile. (NASA)
Scientists at the University of Texas at Austin recently built a particle accelerator that can sit on a tabletop. Most particle accelerators, such as CERN’s Large Hadron Collider (LHC), are massive. The LHC is contained within a tunnel that is 27 kilometers in circumference. (Rafal Zgadzaj)
This is a living brain neuron in culture. Scientists from the University of Southern California have developed a way to see where and how memories are made by engineering microscopic probes that light up synapses in a living neuron in real time by attaching fluorescent markers onto synaptic proteins – all without affecting the neuron’s ability to function. (Don Arnold)
Rice University scientists are conducting research to determine if produce such as spinach and carrots can be encouraged to product more cancer-fighting antioxidants by controlling its circadian cycle with light. Here, a cabbage looper caterpillar makes its way through some of vegetable that were being studied. (Se Kim/Rice University)
Scientists are getting ready to launch a rocket from NASA’s Wallops Flight Facility in Virginia. The five-minute trip will be to study a global electrical current called the dynamo that sweeps through the ionosphere. A chemical trail, like the one here, will help researchers track wind movement to determine how it affects the movement of charged particles in the atmosphere. (NASA)
US, Europe Could Collide to Form Supercontinent
North America and Europe are now separated by the Atlantic Ocean. Geologists have found clues that may signal the beginning of a cycle where the Atlantic will disappear and the continents will collide and form a new supercontinent. (Map: Google)
Taking a trip from the United States to Europe might be much easier in 220 million years, according to a recent study, which suggests that’s when the Atlantic Ocean could close up, causing North America to collide with Europe.
Australian geologists have detected a new subduction zone–when two oceanic plates collide–forming off the coast of Portugal. It’s the first evidence this previously passive margin in the Atlantic Ocean is now becoming active.
Subduction zones, such as the newly discovered one forming near Iberia, form when one of the dozens of tectonic plates that cover our planet dives and ducks beneath another plate, into the layer located just beneath the surface (the mantle) as the two plates converge.
After mapping the ocean floor, the research team found the surface was beginning to fracture, which indicates tectonic activity around the South West Iberia plate margin.
“What we have detected is the very beginnings of an active margin. It’s like an embryonic subduction zone,” said Dr. João Duarte, from Monash University, the study’s lead scientist. “Significant earthquake activity, including the 1755 quake which devastated Lisbon, indicated that there might be convergent tectonic movement in the area. For the first time, we have been able to provide not only evidences that this is indeed the case, but also a consistent driving mechanism.”
The study indicates the subduction zone beginning to form off Portugal’s coast could signal that a new phase of the Wilson Cycle has started. The Wilson Cycle, named for the late Canadian geologist, John Tuzo Wilson, is the periodic opening and closing of the world’s ocean basins, caused by tectonic plate movement.
This cycle is responsible for the joining of continents into supercontinents, which then stabilize and subsequently break up again into individual continents.
Supercontinent Pangaea forms and breaks apart
Over the known history of our planet, a number of these supercontinents have formed and broken up. Pangaea, one of the most famous of these, formed more than 300 million years ago, eventually breaking apart, around 200 million years ago, into the seven continents we’re familiar with today.
The researchers’ findings give other scientists a unique opportunity to observe as a passive margin–the edge of a continental plate that experiences very little tectonic activity–becomes an active margin, which occurs when there is increased tectonic activity because a continental plate is crashing into a nearby oceanic plate, a geological process that takes about 20 million years. Even at this early phase of the process, the new-found subduction zone should provide data that is crucial to refining geodynamic models.
“Understanding these processes will certainly provide new insights on how subduction zones may have initiated in the past and how oceans start to close,” Duarte said.
Scientists Discover How Marine Mammals Hold Their Breath for Long Periods
An otter swims underwater the Detroit, Michigan Zoo (Ellen Meiselman via Flickr/Creative Commons)
Special properties of an oxygen-binding protein in the muscles of marine mammals, such as seals, whales and dolphins, are the reason these animals can hold their breath underwater for long periods of time, according to a new study.
Many of these mammalian divers can hold their breath underwater for over an hour, while land-based mammals, such as humans, can only do so for a few minutes at most.
Scientists from the University of Liverpool, who led the study, were able to identify a unique molecular characteristic of myoglobin, an iron and oxygen-binding protein found in sperm whales and other diving mammals. Until this finding, very little was known about how the molecule is adapted in the diving marine mammals.
The researchers, in collaboration with the University of Manitoba and University of Alaska, found a high concentration of myoglobin, the substance that makes meat look red, in the muscles of the mammalian divers. In fact, the amount was so high in the muscle that it almost looked black in color.
Monachus schauinslandi (Hawaiian Monk Seal) underwater at Five Fathom Pinnacle, Hawaii. (Kent Backman via Wikimedia Commons)
This discovery allowed the scientists to trace the evolution of how the muscles of more than 100 species of mammals, including fossil remains of their ancient predecessors, were able to store oxygen.
“We studied the electrical charge on the surface of myoglobin and found that it increased in mammals that can dive underwater for long periods of time,” said Dr. Michael Berenbrink, from the University of Liverpool, who led the international team of scientists. “We were surprised when we saw the same molecular signature in whales and seals, but also in semi-aquatic beavers, muskrats and even water shrews.”
Mapping the unique molecular signature of myoglobin throughout the mammalian family tree allowed scientists to recreate the muscle oxygen stores found in the extinct ancestors of today’s diving mammals. The team then was able to find the first evidence of a common amphibious forefather of modern sea cows, hyraxes and elephants that lived 65 million years ago in shallow African waters.
While marine mammals like seals, dolphins and whales can stay underwater for long periods of time, humans can only do so for about a minute or so. (gadgetboy32 via Flickr/Creative Commons)
“Our study suggests that the increased electrical charge of myoglobin in mammals that have high concentrations of this protein causes electro-repulsion, like similar poles of two magnets,” said Dr. Scott Mirceta, a member of the research team. “This should prevent the proteins from sticking together and allow much higher concentrations of the oxygen-storing myoglobin in the muscles of these divers.”
“This finding illustrates the strength of combining molecular, physiological and evolutionary approaches to biological problems and, for the first time, allows us to put ‘flesh’ onto the bones of these long extinct divers,” said Berenbrink.
Watch a video on this discovery (University of Liverpool/BBSRC)
Simple Theory May Explain Dark Matter
Artist’s impression of the Milky Way galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of dark matter. (ESO/Calçada)
A number of theories concerning dark matter have been developed over the years, but the Vanderbilt University scientists have come up with a relatively simple theory to explain what has so far been unexplainable.
Top image: Comparison of an anapole field in red with common electric and magnetic dipole field, blue. Middle & Bottom: Anapole field – red and Dipole field – blue (Michael Smeltzer, Vanderbilt University)
In a paper entitled Anapole Dark Matter, they suggest dark matter particles are surrounded by a rare form of electromagnetism.
“There are a great many different theories about the nature of dark matter. What I like about this theory is its simplicity, uniqueness, and the fact that it can be tested,” said Professor Robert Scherrer, a theoretical physicist at Vanderbilt University who performed a detailed analysis along with post-doctoral fellow Chiu Man Ho.
The two physicists believe dark matter might be made out of a type of elementary electrically neutral particle called the Majorana fermion (or Majorana Particle). The existence of this particle was predicted by Italian physicist Ettore Majorana in 1937, but has so far escaped detection.
Fermions – predicted by Paul Dirac in 1928 and named after the renowned physicist Enrico Fermi – are thought to be basic particles that scientists consider to be the building blocks of matter. Some scientists think the Marjorana fermion may be a neutrino, but they haven’t been able determine the basic nature of this unique and mysterious particle.
While a number of physicists have also previously suggested that dark matter is composed of Majorana particles, Scherrer and Ho performed detailed calculations they believe prove the particles are uniquely suitable to have a rare, donut-shaped type of electromagnetic field called an anapole.
Ettore Majorana – Circa 1906. The Marjoran fermion or particle was predicted by him in 1937, but so far has escaped detection. (Wikimedia Commons)
The Majorana fermions are difficult to detect, according to Scherrer and Ho, because this anapole field gives the particles certain properties that make them quite different from others that have more common fields comprised of two poles – north and south, positive and negative.
“Most models for dark matter assume that it interacts through exotic forces that we do not encounter in everyday life,” said Scherrer. “Anapole dark matter makes use of ordinary electromagnetism that you learned about in school: the same force that makes magnets stick to your refrigerator or makes a balloon rubbed on your hair stick to the ceiling. Further, the model makes very specific predictions about the rate at which it should show up in the vast dark matter detectors that are buried underground all over the world. These predictions show that soon the existence of anapole dark matter should either be discovered or ruled out by these experiments.”
Scientists developed the concept of dark matter in the 1930s, while trying to explain discrepancies in the rotational rate of galactic clusters. Since then, astronomers have also found similar inconsistencies in the rate at which stars rotate around individual galaxies. Assuming they contain a large amount of invisible dark matter is the most straightforward way to explain these discrepancies.
NASA is teaming up with LEGO to inspire a new generation of space explorers.
The US space agency and the LEGO group, creator of the popular building brick and model construction kits, are challenging young people to envision the future through a competition called NASA’s Missions: Imagine and Build.
The contest calls on young people to share that vision by using LEGO pieces to create models of future NASA missions and spacecraft.
“It is international in scope…one class is for ages 13 and older and the other one is for ages 16 and older,” said Debbie Rivera, acting director of NASA’s Public Outreach Division.
Toy maker LEGO and NASA are sponsoring a competition that encourages young people to envision the future of space exploration. (LEGO/NASA)
One of the two categories in the competition is Inventing Our Future in Flight, which asks competitors to create an aircraft of the future based on a project NASA is currently working on.
The other category, Imagine Our Future Beyond Earth, encourages entrants to journey into space by using LEGOS to depict one of NASA’s future missions.
Although participants can be as imaginative as they wish, the entries should reflect a future mission NASA is already planning through the 2030s.
Participants will be able to use the LEGO digital designer computer program to help design their models.
Artist’s concept of a solar electric propulsion-based spacecraft. Advanced technologies are an essential part of future missions into deep space. (Analytical Mechanics Associates/NASA)
Entrants will upload pictures of their completed models to any public web-server or photo sharing site such as flickr.com, and then post a link to their pictures on the contest website.
“There will be prizes for the winners, one of which is going to be a LEGO building kit that will be autographed by one of the LEGO designers,” said Rivera. “For one of the contests there will also be an actual trophy that is built out of LEGO bricks. And for winners in both contests there will be NASA commemorative material.”
The deadline for the contest is July 31, 2013 at 1259 UTC.
Ultra-Light Planet Found Outside Solar System
The blue dot is the newly discovered exoplanet, HD95086B, which was captured by ESO’s Very Large Telescope (VLT) in Chile. (ESO)
Astronomers made the discovery using the Very Large Telescope (VLT), located in Chile, which captured the faint object moving near a bright star about 300 light years from Earth. The possible planet has an estimated mass that is four-to-five times that of Jupiter.
Dubbed HD95086b, the planet appears in ESO’s observations as a faint but clear dot close to the star HD95086, which astronomers consider a fairly young star – about 10 to 17 million years old.
The star itself is a little more massive than the Sun and is surrounded by a debris disc, a disk of dust and debris orbiting a star. It was those properties that allowed ESO astronomers to identify the star as an ideal candidate to harbor young massive planets. Astronomers believe the new exoplanet was probably formed within that gaseous and dusty debris disc.
ESO’s Very Large Telescope (VLT) Array on Cerro Paranal Mountain (ESO)
“Its current location raises questions about its formation process. It either grew by assembling the rocks that form the solid core and then slowly accumulated gas from the environment to form the heavy atmosphere, or started forming from a gaseous clump that arose from gravitational instabilities in the disc,” said Anne-Marie Lagrange, a member of the team that made the discovery. “Interactions between the planet and the disc itself or with other planets may have also moved the planet from where it was born.”
Later observations indicated the planetary object moved with the star across the sky, suggesting that it is in orbit with the star.
HD95086 b is believed to orbit its young star at a distance of around 56 times the distance from the Earth to the Sun and twice distance between the Sun and Neptune.
Considering the brightness of its star, ESO astronomers estimate the surface temperature of HD95086b is about 700 degrees Celsius.
Image of the sky around the young star HD95086 in the southern constellation of Carina (The Keel). (ESO)
“This is cool enough for water vapor and possibly methane to exist in its atmosphere. It will be a great object to study with the forthcoming SPHERE instrument on the VLT. Maybe it can also reveal inner planets in the system, if they exist,” said Gaël Chauvin, another member of the team.
Astronomers were able to capture an image of HD95086 b, which is unusual. Most exoplanets are too far away to be properly imaged.
Experts usually have to rely on indirect methods to find planets, such as looking for a star to dim slightly which may be caused by a planet crossing in front of it. The ESO says there are only about 12 extrasolar or exoplanets that have been discovered using direct imaging.
“Direct imaging of planets is an extremely challenging technique that requires the most advanced instruments, whether ground-based or in space,” says Julien Rameau of the Institute of Planetology and Astrophysics in Grenoble, France who is first author of the paper announcing the discovery. “Only a few planets have been directly observed so far, making every single discovery an important milestone on the road to understanding giant planets and how they form.”
