News Article | March 28, 2017
There is a new focus at NASA on small satellite missions as forerunners for larger missions of the Solar System. The NASA program, Planetary Science Deep Space SmallSat Studies gives a window for projects with small satellites to study Solar System's celestial bodies. In the latest step, NASA has awarded $3.6 million to ten projects for concept planning awaiting their roll out after a few months. Generally, small satellites weigh less than 400 pounds. Among the 10 projects selected, two are Venus centric with a focus on noble gasses and isotopes. One CubeSat project will be looking at ultraviolet absorption and atmosphere's nightglow emissions. NASA's Goddard Space Flight Center will be sending a 12-unit CubeSat to investigate the hydrogen cycle of the moon. The small satellite from Johns Hopkins University will target an asteroid with a seismometer to examine its surface and interiors. Another CubeSat from Purdue University will image Phobos and Deimos — the Martian moons. NASA Ames will deploy a CubeSat to Mars focusing on climate studies. The probe of Hampton University will be on Uranus and its atmosphere. The magnetosphere of Jupiter will be the core area of investigation for the project of Southwest Research Institute. Basically, SmallSats handle the delivery of preliminary data for upcoming bigger projects. The cost of launching SmallSats is also nominal. "These small but mighty satellites have the potential to enable transformational science. They guide NASA's development of small spacecraft technologies for deep space science investigation," noted Jim Green, director of the Planetary Science Division at NASA Headquarters. Green added that the agency is investing in SmallSats after being convinced of their utility for cutting edge scientific investigations. A range of merits justify SmallSats such as deployment from bigger spacecraft to target-specific investigations to back main missions. The Mars mission of NASA will use this approach by despatching two small satellites for advanced data. NASA is also buoyed by the 2016 report by the US National Academies that said SmallSats technology has come of age to provide high-value science. There are many cost benefits from the use of SmallSats. They also offer the flexibility to operate in constellations. "What we're seeing is a capability that we haven't really seen before in terms of small satellites that can do pretty good science at a much-reduced cost compared to the big missions," said Steve Mackwell from the Universities Space Research Association (USRA) in Maryland. Mackwell said miniaturization helps in deploying SmallSats where larger missions had been thought about. It is an unprecedented opportunity in using them to explore inner Solar System bodies like the Venus and Moon. Green noted that miniature satellites had posed challenges in the past with problems like difficulties around power and communication. Mackwell, however, points that there a change and critical advances have been made in their functioning. An example is compact propulsion systems to reach places where they can ride and maneuver to the ultimate destination. Also, innovations have come up to incorporate solar panels into SmallSats to boost capabilities. More progress is being made on the technology front. An example is engineers at Nasa's Glenn Research Center demonstrating printed electronics suitable for operating in the harsh conditions at Venus. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | April 19, 2017
Astronomers on Wednesday night will be keeping a close eye on a big asteroid that's zooming past Earth. Telescopes like the Arecibo Observatory — a huge radio dish built inside of a Puerto Rican sinkhole — have already started filming the tumbling space rock, called 2014 JO25, by pinging it with radar and recording the echoes. Below is one of the first radar videos (made by Arecibo) that astronomers took of the asteroid, on April 17. NASA said the space rock will fly within about 1.1 million miles of Earth, or roughly 4.6 times the distance from our planet to the moon, on April 19. Because it will fly so close to Earth, it has earned the label of a "potentially hazardous asteroid," or PHA. However, NASA says 2014 JO25 "will fy safely past Earth" and isn't due to swing by again for more than 400 years. The rock is estimated to be about 2,030 feet across, NASA said in an April 6 press release. That's roughly between the height of the One World Trade Center in New York City and Shanghai Tower in China — two of the tallest skyscrapers on Earth. But Edgard Rivera-Valentín, a planetary scientist with the Universities Space Research Association who studies Arecibo data, said it may actually be much larger than that. "Arecibo revealed that this object ... is twice as big as originally estimated and is shaped like a peanut," Rivera-Valentín told Business Insider in an email, adding that Arecibo and other radar observatories will take their best photos on Wednesday night. "[A] little bit more time is needed to clearly get at the size of the object" and analyze that data, he said. NASA's Deep Space Network antenna at Goldstone, California, also recorded the asteroid on April 18. The 230-foot-wide dish photographed the 30 radar images of the space rock (above) as it hurled toward the vicinity of Earth from about 1.9 million miles away. The rock's "peanut" shape comes from the fact that it's a "contact binary," the term for when two rocks smoosh together in space. Rivera-Valentín previously told Business Insider that contact binaries make up about one in every six space rocks, which makes them very common leftovers of our solar system's formation.
News Article | April 17, 2017
Millions of pieces of human-made trash are now orbiting the Earth. Some are tiny, others are large enough to be seen with a telescope, but all pose a risk to space craft and satellites. And according to experts the threat is growing as space becomes more and more crowded. Some 23,000 pieces of space junk are large enough to be tracked by the US Space Surveillance Network. But most objects are under 10cm (4in) in diameter and can't be monitored. Even something the size of a paper clip can cause catastrophic damage. "At the moment we're not tracking stuff that small," says Brian Weeden of the Secure World Foundation, a Washington based organisation dedicated to the sustainable use of space. "And that's important because something as small as a centimetre can cause problems if it runs into a satellite." Collisions are rare, but half of all near-misses today are caused by debris from just two incidents. In 2007, China destroyed one of its own satellites with a ballistic missile. In 2009 an American commercial communications satellite collided with a defunct Russian weather satellite. As recently as 2015, the debris from that collision forced the crew of the International Space Station to evacuate to the Soyuz capsule. No-one was harmed, but the debris will likely remain in the Earth's orbit for hundreds, if not thousands of years. Scientists are experimenting with ways to clean up space. So far, there is no space vacuum cleaner. And debris have a nasty habit of creating more debris that get exponentially smaller and harder to spot. More than 7,000 satellites have been put into space but only 1,500 are currently functioning. And within the next decade the number could increase to 18,000 with the planned launch of mega-constellations - large groups of satellites aimed at improving global internet coverage. "That's going to amplify the problems we have with tracking objects, predicting close approaches and preventing collisions," says Weeden. "The problem is going to become much, much harder in the next several years." Everything travels at the same speed relative to its altitude in space. That's not a problem if everything moves in the same direction, says Weeden, but objects often follow different orbits and can cross paths - a situation known as a conjunction. "Think of it like all the cars on a highway are doing a hundred miles an hour. If the car next to you is doing that speed you don't really notice it. But if the car coming at you is doing that speed - you'll collide at 200 miles an hour." Lauri Newman is NASA's traffic cop at Goddard Space Flight Center, Maryland. She is responsible for using military data to decide whether the space agency's unmanned craft such as satellites need to be moved to prevent a collision with debris. "Satellites can protect themselves from things that are smaller than a centimetre by putting up extra shielding," she says. "But the things between one and 10cm - if you can't track it there's nothing you can do." Satellite technology is essential to almost every modern convenience - from communications to GPS navigation and downloading movies on demand. It's also vital to national security. "It affects everything," says Lt Col Jeremy Raley a program manager at Darpa, the Defense Advanced Research Projects Agency. "So I need to be able to see everything (in space) all the time and know what it is when I see it." That's why Darpa is leading military efforts to find better ways of tracking space debris. In October last year it delivered a massive 90-ton telescope to the US Air Force at White Sands, New Mexico. The Space Surveillance Telescope is designed to penetrate Geosynchronous orbit (GEO) which is becoming increasingly important. Communications and television satellites in GEO can remain in a fixed position above the Earth, offering uninterrupted service. "The telescope is a big deal because it can see more objects and smaller objects. And rather than having to take time to look at an object and then look at something else, it can keep track of things on a more persistent basis," says Lt Col Raley. But that level of scrutiny costs money and also raises the question of whether the US should share its data to improve space safety overall. That was one of the issues discussed at a recent symposium in Washington organised by the Universities Space Research Association and the Space Policy Institute at George Washington University. Experts discussed who should manage space, who should be responsible for debris and whether there should be an agreed set of international guidelines for the sustainable use of space. "There's a classic public policy, economic question here," says Weeden. "It's like pollution. It might not be worth it for you to pick up your garbage and avoid polluting the river, but there are costs to society if you don't. How do you get people to be responsible when the costs may not be borne by them?" No single nation or entity is responsible for space although in 1959 the UN set up a Committee on the Peaceful Uses of Outer Space (COPUOS). "There are currently 85 countries that are members of this committee and they range from space powers such as the US, Russia and China to countries like Costa Rica that don't even have a satellite in orbit but are an end user of satellite functions," says Weeden. "Getting all of those countries to agree on this stuff is a really difficult challenge." But with more nations and commercial organisations operating in Earth's orbit and many looking beyond, such issues are becoming increasingly urgent. Do nothing is no longer an option.
News Article | February 16, 2017
Gif composed of thirteen delay-Doppler images of Comet 45P/HMP after 2 hours of observation. Credit: Universities Space Research Association Though not visible to the naked eye or even with binoculars, the green-tailed Comet 45P/Honda-Mrkos-Pajdusakova (HMP) did not escape the gaze of the world-renowned Arecibo Observatory. Scientists from the University of Arizona's Lunar and Planetary Laboratory (LPL) and the Universities Space Research Association (USRA) at Arecibo Observatory have been studying the comet with radar to better understand its solid nucleus and the dusty coma that surrounds it. "Comets are remnants of the planet forming process and are part of a group of objects made of water ice and rocky material that formed beyond Neptune," noted Dr. Ellen Howell, Scientist at LPL and the leader of the observing campaign at Arecibo. "Studying these objects gives us an idea of how the outer reaches of our Solar System formed and evolved over time." Studying the comet with radar not only very precisely determines its orbit, allowing scientists to better predict its location in the future, but also gives a glimpse of the typically unseen part, the comet's nucleus, which is usually hidden behind the cloud of gas and dust that makes up the its coma and tail. "The Arecibo Observatory planetary radar system can pierce through the comet's coma and allows us to study the surface properties, size, shape, rotation, and geology of the comet nucleus," said Dr. Patrick Taylor, USRA Scientist and Group Lead for Planetary Radar at Arecibo. "We gain roughly the same amount of knowledge from a radar observation as a spacecraft flyby of the same object, but at considerably less cost." In fact, the new radar observations have revealed Comet 45P/HMP to be somewhat larger than previously estimated. The radar images suggest a size of about 1.3 km (0.8 mi) and that it rotates about once every 7.6 hours. "We see complex structures and bright regions on the comet and have been able to investigate the coma with radar," indicated Cassandra Lejoly, graduate student at the University of Arizona. This comet is only the seventh imaged using radar because comets rarely come close enough to the Earth to get such detailed radar images. In fact, though 45P/HMP has an orbital period of about 5.3 years, it rarely passes close to Earth, as it is doing now. Comet 45P is one of a group of comets called Jupiter family comets (JFCs), whose orbits are controlled by Jupiter's gravity and typically orbit the sun about every 6 years. Comet 45P/HMP, which is passing by Earth at a speed of about 23 km/s (relative to Earth) and a close approach of about 32 Earth-Moon distances, will be observed widely at different wavelengths to characterize the gas and dust emanating from the nucleus that forms the coma. As comets orbit the sun, the ices sublime from solids to gases and escape the nucleus. The nucleus gradually shrinks and will disappear completely within in less than a million years. Radar observations at Arecibo of Comet 45P/HMP began on February 9, 2017 and will continue through February 17, 2017. Explore further: Comet's trip past Earth offers first in a trio of opportunities
News Article | February 22, 2017
Needless to say, the definition they adopted resulted in fair degree of controversy from the astronomical community. For this reason, a team of planetary scientists – which includes famed "Pluto defender" Alan Stern – have come together to propose a new meaning for the term "planet". Based on their geophysical definition, the term would apply to over 100 bodies in the solar system, including the moon itself. The current IAU definition (known as Resolution 5A) states that a planet is defined based on the following criteria: "(1) A "planet" is a celestial body that (a) is in orbit around the sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit. (2) A "dwarf planet" is a celestial body that (a) is in orbit around the sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite. (3) All other objects , except satellites, orbiting the sun shall be referred to collectively as "small solar-system bodies" Because of these qualifiers, Pluto was no longer considered a planet, and became known alternately as a "dwarf planet", Plutiod, Plutino, Trans-Neptunian Object (TNO), or Kuiper Belt Object (KBO). In addition, bodies like Ceres, and newly discovered TNOs like Eris, Haumea, Makemake and the like, were also designated as "dwarf planets". Naturally, this definition did not sit right with some, not the least of which are planetary geologists. Led by Kirby Runyon – a final year PhD student from the Department of Earth and Planetary Sciences at Johns Hopkins University – this team includes scientists from the Southwest Research Institute (SwRI) in Boulder, Colorado; the National Optical Astronomy Observatory in Tuscon, Arizona; the Lowell Observatory in Flagstaff, Arizona; and the Department of Physics and Astronomy at George Mason University. Their study – titled "A Geophysical Planet Definition", which was recently made available on the Universities Space Research Association (USRA) website – addresses what the team sees as a need for a new definition that takes into account a planet's geophysical properties. In other words, they believe a planet should be so-designated based on its intrinsic properties, rather than its orbital or extrinsic properties. From this more basic set of parameters, Runyon and his colleagues have suggested the following definition: "A planet is a sub-stellar mass body that has never undergone nuclear fusion and that has sufficient self-gravitation to assume a spheroidal shape adequately described by a triaxial ellipsoid regardless of its orbital parameters." As Runyon told Universe Today in a phone interview, this definition is an attempt to establish something that is useful for all those involved in the study of planetary science, which has always included geologists: "The IAU definition is useful to planetary astronomers concerned with the orbital properties of bodies in the solar system, and may capture the essence of what a 'planet' is to them. The definition is not useful to planetary geologists. I study landscapes and how landscapes evolve. It also kind of irked me that the IAU took upon itself to define something that geologists use too. "The way our brain has evolved, we make sense of the universe by classifying things. Nature exists in a continuum, not in discrete boxes. Nevertheless, we as humans need to classify things in order to bring order out of chaos. Having a definition of the word planet that expresses what we think a planet ought to be, is concordant with this desire to bring order out of chaos and understand the universe." The new definition also attempts to tackle many of the more sticky aspects of the definition adopted by the IAU. For example, it addresses the issue of whether or not a body orbits the sun – which does apply to those found orbiting other stars (i.e. exoplanets). In addition, in accordance with this definition, rogue planets that have been ejected from their solar systems are technically not planets as well. And then there's the troublesome issue of "neighborhood clearance". As has been emphasized by many who reject the IAU's definition, planets like Earth do not satisfy this qualification since new small bodies are constantly injected into planet-crossing orbits – i..e near-Earth objects (NEOs). On top of that, this proposed definition seeks to resolve what is arguably one of the most regrettable aspects of the IAU's 2006 resolution. "The largest motivation for me personally is: every time I talk about this to the general public, the very next thing people talk about is 'Pluto is not a planet anymore'," said Runyon. "People's interest in a body seems tied to whether or not it has the name 'planet' labelled on it. I want to set straight in the mind of the public what a planet is. The IAU definition doesn't jive with my intuition and I find it doesn't jive with other people's intuition." The study was prepared for the upcoming 48th Lunar and Planetary Science Conference. This annual conference – which will be taking place this year from March 20th-24th at the Universities Space Research Association in Houston, Texas – will involve specialists from all over the worlds coming together to share the latest research findings in planetary science. Here, Runyon and his colleagues hope to present it as part of the Education and Public Engagement Event. It is his hope that through an oversized poster, which is a common education tool at Lunar and Planetary Science Conference, they can show how this new definition will facilitate the study of the solar system's many bodies in a way that is more intuitive and inclusive. "We have chosen to post this in a section of the conference dedicated to education," he said. "Specifically, I want to influence elementary school teachers, grades K-6, on the definitions that they can teach their students. This is not the first time someone has proposed a definition other than the one proposed by the IAU. But few people have talked about education. They talk among their peers and little progress is made. I wanted to post this in a section to reach teachers." Naturally, there are those who would raise concerns about how this definition could lead to too many planets. If intrinsic property of hydrostatic equilibrium is the only real qualifier, then large bodies like Ganymede, Europa, and the moon would also be considered planets. Given that this definition would result in a solar system with 110 "planets", one has to wonder if perhaps it is too inclusive. However, Runyon is not concerned by these numbers. "Fifty states is a lot to memorize, 88 constellations is a lot to memorize," he said. "How many stars are in the sky? Why do we need a memorable number? How does that play into the definition? If you understand the periodic table to be organized based on the number of protons, you don't need to memorize all the atomic elements. There's no logic to the IAU definition when they throw around the argument that there are too many planets in the solar system." Since its publication, Runyon has also been asked many times if he intends to submit this proposal to the IAU for official sanction. To this, Runyon has replied simply: "No. Because the assumption there is that the IAU has a corner on the market on what a definition is. We in the planetary science field don't need the IAU definition. The definition of words is based partly on how they are used. If [the geophysical definition] is the definition that people use and what teachers teach, it will become the de facto definition, regardless of how the IAU votes in Prague." Regardless of where people fall on the IAU's definition of planet (or the one proposed by Runyon and his colleagues) it is clear that the debate is far from over. Prior to 2006, there was no working definition of the term planet; and new astronomical bodies are being discovered all the time that put our notions of what constitutes a planet to the test. In the end, it is the process of discovery which drives classification schemes, and not the other way around. Explore further: UCLA professor proposes simpler way to define what makes a planet
News Article | February 24, 2017
Obstacles to determine how much water is locked up in the world's mountain snow have yet to be conquered. No single instrument, even the space-based, had ever come close to hurdle it. Against this backdrop, NASA's SnowEx has joined the fray with a goal — to find the best snow-measuring techniques. "This is the most comprehensive campaign we have ever done on snow," declared Edward Kim, a remote sensing scientist at NASA Goddard and the SnowEx project scientist. Seventy percent of the world's surface is covered by water of which only 2.5 percent of this is fresh water. Of the available fresh water, more than two-thirds are locked in glaciers. In addition, about 20 percent of the Earth's land surface is covered by snow land, which also has water locked in it. This has far-reaching consequences on a society where more than a billion people depend largely on snow for their fresh water, Kim said. The water locked in the world's mountain snow has other consequences for people, such as devastating floods, drought, and instability when its supply is scarce. It is said some 663 million people worldwide have no access to drinking water. Snow packs that melt, for instance, provided a major supply to the annual streamflow in the western United States when spring and summer arrive. Yet there is no information available, at present, how much water will pour out from melting snow owing to inadequate ground measurement sites. This situation has led to the birth of SnowEx. Scientists and resource managers wanted to have a comprehensive view from space the amount of water contained in the snow-covered land that will eventually melt into streams, rivers, and reservoirs. The snow-covered mountains of Colorado were combed by aircraft with sensors as researchers have completed the first flights of the SnowEx campaign this month. The NASA-led experiment uses five aircraft with 10 sensors with a goal to find the right combination to develop instruments and techniques which could be used in a snow-observing space mission in the future. "We will also figure out a better way to optimize the use of existing satellites to make measurements," Jared Entin of the Terrestrial Hydrology Program at NASA said. Multiple sensors are needed to address the difficulty in measuring water content in snow including those under the canopies. "We will work closely with our ground team to try new techniques to see if we can figure out how to do that accurately," said Charles Gatebe from NASA Goddard, SnowEx deputy project scientist and senior scientist with Universities Space Research Association. The Terrestrial Hydrology Program at NASA Headquarters in Washington, D.C. sponsored SnowEx while NASA's Goddard Space Flight Center in Greenbelt, Maryland managed the multi-year campaign. Storage of data generated from the campaign will be at the National Snow and Ice Data Center in Boulder, Colorado and will be accessible to all. The campaign is expected to "generate the best ideas from the global community of snow experts," Kim said. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
Cecil D.J.,University of Alabama in Huntsville |
Blankenship C.B.,Universities Space Research Association
Journal of Climate | Year: 2012
An 8-yr climatology of storms producing large hail is estimated from satellite measurements using Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E). This allows a unique, consistent comparison between regions that cannot be consistently compared using ground-based records because of varying data collection standards. Severe hailstorms are indicated most often in a broad region of northern Argentina and southern Paraguay and a smaller region in Bangladesh and eastern India. Numerous hailstorms are also estimated in the central and southeastern United States, northern Pakistan and northwestern India, central and western Africa, and southeastern Africa (and adjacent waters). Fewer hailstorms are estimated for other regions over land and scattered across subtropical oceans. Very few are estimated in the deep tropics other than in Africa. Most continental regions show seasonality with hailstorms peaking in late spring or summer. The South Asian monsoon alters the hailstorm climatology around the Indian subcontinent. About 75% of the hailstorms on the eastern side (around Bangladesh) occur from April through June, generally before monsoon onset. Activity shifts northwest to northern India in late June and July. An arc along the foothills in northern Pakistan becomes particularly active from mid-June through mid-August. The AMSR-E measurements are limited to early afternoon and late night. Tropical Rainfall Measuring Mission (TRMM) measurements are used to investigate diurnal variability in the tropics and subtropics. All of the prominent regions have hailstorm peaks in late afternoon and early evening. The United States and central Africa have the fewest overnight and early morning storms, while subtropical South America and Bangladesh have the most. © 2012 American Meteorological Society.
Agency: NSF | Branch: Continuing grant | Program: | Phase: PHYSICAL & DYNAMIC METEOROLOGY | Award Amount: 124.86K | Year: 2013
With this award, the investigators will examine physical processes occurring in growing and evolving convective clouds as they begin to produce lightning. The study will utilize: Satellite-based cloud observations and retrieved cloud properties, including time-series (5-15-min) of Geostationary Operational Environmental Satellite (GOES) and Meteosat Second Generation (MSG) visible and infrared (IR) measurements; S-band dual-polarimetric National Weather Service Surveillance 1988 Doppler (WSR-88D) radar observations across the United States; Ground-based VHF Lightning Mapping Array (LMA) observations (e.g., over Northern Alabama, Central Oklahoma); Observations collected during the Cloud processes of the main precipitation systems in Brazil: A contribution to cloud resolving modeling and to the Global Precipitation Measurement(CHUVA) campaign; Retrieved aerosol observations from satellites such as MODerate resolution Imaging Spectroradiometer (MODIS), and ground, such as from the AErosol RObotic NETwork (AERONET).
The award seeks to address a fundamental question in lightning prediction: How does the combination of multi-scale processes influence total lightning production? The corollary to this is: How do we obtain a longer lead time (>10-15 min) in lightning forecasting?
The specific goals are: (1) To improve understanding of the physical processes and precursory signals of lightning evolution within the 0-1 h timeframe through the collection and interpretation of high-temporal and spatial resolution space- and ground-based remote sensing observations of hydrometeor and aerosol type, amount and distribution; (2) To seek improvement in lightning amount nowcasting skill for longer lead-time (~30-45 min) and higher accuracy using combined data from geostationary satellite observations, radar and models; (3) To significantly bolster graduate- and undergraduate-level university education directly through transition of scientific discoveries to students, and indirectly via curriculum enhancements.
The Broader Impacts will be improving understanding of lightning processes that are inherently difficult to observe, more skillful 0-1 hour quantitative lightning nowcasts, and exploitation of WSR-88D dual-polarimetric data. Improved lightning nowcasts will benefit the general public, and especially the aviation industry that suffer substantial costs due to lightning-disrupted ground operations. Relatively few studies have developed physical relationships related to lightning nowcasting using combined datasets with a focus on satellite data. Use of WSR-88D radar in conjunction with satellite is timely in light of new observations from the GOES-R Advanced Baseline Imager and Geostationary Lightning Mapper expected in 2016, and from the Meteosat Third Generation Lightning Imager in ~2019. In addition, collaboration with other university scientists and graduate students will further extend this research to the larger academic and educational community.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 219.79K | Year: 2011
The collaborative research lead by Dr. Andersson (Universities Space Research Association), Dr. Jones (University of Minnesota), and Dr. Lazarian (University of Wisconsin, Madison) advances our ability to trace magnetic fields in the interstellar medium and molecular clouds through new multi-wavelength observations and theoretical modeling. It leads to a better understanding of the foregrounds to the cosmic microwave background (CMB) polarization through targeted observations of interstellar grain alignment and modeling based on the leading theoretical paradigm. The combined new quantitative effort addresses interstellar grain alignment mechanisms. A quantitative theory based on radiative alignment torques provides specific, testable predictions of the grain alignment as functions of the environment and grain characteristics. Observations, employing optical and near-infrared (NIR) polarimetry, directly probe the theoretical predictions of the variations of grain alignment efficiencies from the molecular cloud surfaces to the depths where (sub-)mm wave polarized emission is observed. Extensive modeling of the grain alignment, simulating the polarization arising from aligned grains, supports interpretations of the observations. A quantitative understanding of the alignment mechanism is important to understand the structure and strength of the magnetic field (through the geometry of the polarization vectors and the Chandrasekhar-Fermi method, respectively). The impact on related research ranges from models of star formation (through a reliable magnetic field tracing) to the physics of Early Universe (through a reliable separation of polarized dust foreground from the CMB polarized radiation) as well as a better understandinging micro-physics of interstellar dust grains. This project trains young researchers and graduate students in the acquisition, analysis and interpretation of the optical and NIR observations, and on computational models necessary for the study of astrophysical magnetic fields and the nature of interstellar polarization.
Universities Space Research Association | Date: 2012-08-29
A process for producing isotopes by continuously flowing a liquid stream, carrying capsules of target nuclei (NP-237) in solution, through a nuclear reactor (a TRIGA style nuclear reactor). Upon removal from the core of the nuclear reactor and after allowing for the decay of Np-238 to Pu-238, the capsules are emptied and the mixture of elements and isotopes are chemically separated using solvent extraction or ion exchange. Isotopes that are capable of further processing into Pu-238 are recycled to the core for further processing