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  • richardmitnick 10:45 am on February 20, 2017 Permalink | Reply
    Tags: , GISS global climate models over the years, NASA Goddard   

    From Goddard: “Forcings in GISS Climate Models” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    2016-02-05
    Dr. Makiko Sato
    Dr. Gavin Schmidt.

    We summarize here forcing datasets used in GISS global climate models over the years. Note that the forcings are estimates that may be revised as new information or better understandings of the source data become available. We archive both our current best estimates of the forcings, along with complete sets of forcings used in specific studies. All radiative forcings are with respect to a specified baseline (often conditions in 1850 or 1750).

    Forcings can be specified in a number of different ways. Traditionally, forcings have been categorised based on specific components in the radiative transfer calculation (concentrations of greenhouse gases, aerosols, surface albedo changes, solar irradiance, etc.). More recently, attribution of forcings have been made via specific emissions (which may have impacts on multiple atmospheric components) or by processes (such as deforestation) that impact multiple terms at once (e.g., Shindell et al., 2009).

    Additionally, the definition of how to specify a forcing can also vary. A good description of these definitions and their differences can be found in Hansen et al. (2005). Earlier studies tend to use either the instantaneous radiative imbalance at the tropopause (Fi), or very similarly, the radiative imbalance at the Top-of-the-Atmosphere (TOA) after stratospheric adjustments — the adjusted forcing (Fa). More recently, the concept of an ‘Effective Radiative Forcing’ (Fs) has become more prevalent, a definition which includes a number of rapid adjustments to the imbalance, not just the stratospheric temperatures. For some constituents, these differences are slight, but for some others (particularly aerosols) they can be significant.

    In order to compare radiative forcings, one also needs to adjust for the efficacy of the forcing relative to some standard, usually the response to increasing CO2. This is designed to adjust for particular geographical features in the forcing that might cause one forcing to trigger larger or smaller feedbacks than another. Applying the efficacies can then make the prediction of the impact of multiple forcings closely equal the net impact of all of them. This is denoted Fe in the Hansen description. Efficacies can depend on the specific context (i.e. they might be different for a very long term simulation, compared to a short term transient simulation) and don’t necessarily disappear by use of the different forcing definitions above.

    Quantifiying the actual forcing within a global climate model is quite complicated and can depend on the baseline climate state. This is therefore an additional source of uncertainty. Within a modern complex climate model, forcings other than solar are not imposed as energy flux perturbations. Rather, the flux perturbations are diagnosed after the specific physical change is made. Estimates of forcings for solar, volcanic and well-mixed GHGs derived from simpler models may be different from the effect in a GCM. Forcings from more heterogenous forcings (aerosols, ozone, land use, etc.) are most often diagnosed from the GCMs directly.
    Forcings in the CMIP5 Simulations

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    Fig. Instantaneous radiative forcing at the tropopause (W/m2) in the E2-R NINT ensemble. (a) Individual forcings and (b) Total forcing, along with the separate sums of natural (solar, volcanic and orbital) and anthropogenic forcings. (Updated: 3/12/2016)

    Calculations and descriptions of the forcings in the GISS CMIP5 simulations (1850-2012) can be found in Miller et al. (2014). Data for these figures are available here and here. (Note the iRF figure and values were corrected on 3/12/2016) to account for a missing forcing in the ‘all forcings’ case. Fig. 4 in Miller et al (2014) was also updated). Snapshots of the ERF (Fs) and adjusted forcings (Fa) from these simulations. Note that the forcings from 2000 (or 2005 in some cases) are extrapolations taken from the RCP scenarios, and the real world has diverged slightly from them.

    Further estimates of the responses, including temperatures and the ocean heat content changes, and efficacies are available in the supplementary material associated with Marvel et al. (2016).

    Forcings in Hansen et al. (2011)

    The following chart of forcings from 1880-2011 is taken from Hansen et al. (2011):

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    5

    Data is updated from the CMIP3 studies below (e.g., Hansen et al. 2007a, b) and extended to 2011 using assumptions outlined in the paper. The separate radiative forcing data (Fe) are available here (Net forcing). The figures are also available as PDFs here and here.

    Forcings in the CMIP3 simulations

    The following chart of forcings from 1750-2000 is taken from Hansen et al. (2005):

    6

    Figure is also available in PDF format. (Source: Figure 28 of Hansen et al. (2005). More details, including maps and timeseries of individual forcings are available on the Efficacy web pages.

    See the full article here.

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus

    NASA/Goddard Campus

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  • richardmitnick 6:20 pm on February 14, 2017 Permalink | Reply
    Tags: Downlink communications, Lasers Could Give Space Research its 'Broadband' Moment, NASA Goddard   

    From JPL-Caltech: “Lasers Could Give Space Research its ‘Broadband’ Moment” 

    NASA JPL Banner

    JPL-Caltech

    February 14, 2017
    Andrew Good
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-393-2433
    andrew.c.good@jpl.nasa.gov

    1
    Several upcoming NASA missions will use lasers to increase data transmission from space. Image Credit: NASA’s Goddard Space Flight Center/Amber Jacobson, producer

    Thought your Internet speeds were slow? Try being a space scientist for a day.

    The vast distances involved will throttle data rates to a trickle. You’re lucky if a spacecraft can send more than a few megabits per second (Mbps) — a pittance even by dial-up standards.

    But we might be on the cusp of a change. Just as going from dial-up to broadband revolutionized the Internet and made high-resolution photos and streaming video a given, NASA may be ready to undergo a similar “broadband” moment in coming years.

    The key to that data revolution will be lasers. For almost 60 years, the standard way to “talk” to spacecraft has been with radio waves, which are ideal for long distances. But optical communications, in which data is beamed over laser light, can increase that rate by as much as 10 to 100 times.

    High data rates will allow researchers to gather science faster, study sudden events like dust storms or spacecraft landings, and even send video from the surface of other planets. The pinpoint precision of laser communications is also well suited to the goals of NASA mission planners, who are looking to send spacecraft farther out into the solar system.

    “Laser technology is ideal for boosting downlink communications from deep space,” said Abi Biswas, the supervisor of the Optical Communications Systems group at NASA’s Jet Propulsion Laboratory, Pasadena, California. “It will eventually allow for applications like giving each astronaut his or her own video feed, or sending back higher-resolution, data-rich images faster.”

    ___________________________________________________________________

    NASA’s space lasers
    Past and future NASA projects involving laser communications:

    Name: Lunar Laser Communications Demonstration (LLCD)
    Led by: Goddard Space Flight Center
    Year: 2013
    Objective: Was NASA’s first system for two-way communication using a laser instead of radio waves. An error-free uplink data rate of 20 Mbps transmitted from a primary ground station in New Mexico to NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE), a spacecraft orbiting the moon. Demonstrated an error-free downlink rate of 622 Mbps — the equivalent of streaming 30 channels of HDTV from the moon.

    Name: Optical Payload for Lasercomm Science (OPALS)
    Led by: JPL
    Year: 2014
    Objective: Testing laser communications from the International Space Station. Beamed a video file every 3.5 seconds for a total of 148 seconds. With traditional downlink methods, sending the 175-megabit video just once would have taken 10 minutes.

    Name: Laser Communications Relay Demonstration (LCRD)
    Led by: Goddard Space Flight Center
    Year: 2019
    Objective: Will relay laser signals between telescopes at Table Mountain, California, and in Hawaii through a relay satellite in geostationary orbit during a two-year demonstration period. The system is designed to operate for up to five years to prove the everyday reliability of laser communications for future NASA missions.

    Name: Deep Space Optical Communications (DSOC)
    Led by JPL
    Year: 2023
    Objective: To test laser communications from deep space. An upcoming NASA Discovery mission called Psyche will fly to a metallic asteroid starting in 2023. Psyche is planned to host a laser device called DSOC, which would beam data down to a telescope at Palomar Mountain Observatory in California.
    ___________________________________________________________________

    Science at the speed of light

    Both radio and lasers travel at the speed of light, but lasers travel in a higher-frequency bandwidth. That allows them to carry more information than radio waves, which is crucial when you’re collecting massive amounts of data and have narrow windows of time to send it back to Earth.

    A good example is NASA’s Mars Reconnaissance Orbiter, which sends science data at a blazing maximum of 6 Mbps. Biswas estimated that if the orbiter used laser comms technology with a mass and power usage comparable to its current radio system, it could probably increase the maximum data rate to 250 Mbps.

    That might still sound stunningly slow to Internet users. But on Earth, data is sent over far shorter distances and through infrastructure that doesn’t exist yet in space, so it travels even faster.

    Increasing data rates would allow scientists to spend more of their time on analysis than on spacecraft operations.

    “It’s perfect when things are happening fast and you want a dense data set,” said Dave Pieri, a JPL research scientist and volcanologist. Pieri has led past research on how laser comms could be used to study volcanic eruptions and wildfires in near real-time. “If you have a volcano exploding in front of you, you want to assess its activity level and propensity to keep erupting. The sooner you get and process that data, the better.”

    That same technology could apply to erupting cryovolcanoes on icy moons around other planets. Pieri noted that compared to radio transmission of events like these, “laser comms would up the ante by an order of magnitude.”

    Clouding the future of lasers

    That’s not to say the technology is perfect for every scenario. Lasers are subject to more interference from clouds and other atmospheric conditions than radio waves; pointing and timing are also challenges.

    Lasers also require ground infrastructure that doesn’t yet exist. NASA’s Deep Space Network, a system of antenna arrays located across the globe, is based entirely on radio technology. Ground stations would have to be developed that could receive lasers in locations where skies are reliably clear.

    Radio technology won’t be going away. It works in rain or shine, and will continue to be effective for low-data uses like providing commands to spacecraft.

    Next steps

    Two upcoming NASA missions will help engineers understand the technical challenges involved in conducting laser communications in space. What they’ll learn will advance lasers toward becoming a common form of space communication in the future.

    The Laser Communications Relay Demonstration (LCRD), led by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is due to launch in 2019. LCRD will demonstrate the relay of data using laser and radio frequency technology. It will beam laser signals almost 25,000 miles (40,000 kilometers) from a ground station in California to a satellite in geostationary orbit, then relay that signal to another ground station. JPL is developing one of the ground stations at Table Mountain in southern California. Testing laser communications in geostationary orbit, as LCRD will do, has practical applications for data transfer on Earth.

    Deep Space Optical Communications (DSOC), led by JPL, is scheduled to launch in 2023 as part of an upcoming NASA Discovery mission. That mission, Psyche, will fly to a metallic asteroid, testing laser comms from a much greater distance than LCRD.

    The Psyche mission has been planned to carry the DSOC laser device onboard the spacecraft. Effectively, the DSOC mission will try to hit a bullseye using a deep space laser — and because of the planet’s rotation, it will hit a moving target, as well.

    http://go.nasa.gov/2gBzbyx

    See the full article here .

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 6:03 pm on February 14, 2017 Permalink | Reply
    Tags: , NASA Goddard, Quantum dot spectrometer   

    From Goddard: “NASA and MIT Collaborate to Develop Space-Based Quantum-Dot Spectrometer” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Feb. 14, 2017
    Lori Keesey
    lori.keesey@nasa.gov
    NASA’s Goddard Space Flight Center

    1
    Principal Investigator Mahmooda Sultana has teamed with the Massachusetts Institute of Technology to develop a quantum dot spectrometer for use in space. In this photo, she is characterizing the optical properties of the quantum dot pixels.
    Credits: NASA/W. Hrybyk

    A NASA technologist has teamed with the inventor of a new nanotechnology that could transform the way space scientists build spectrometers, the all-important device used by virtually all scientific disciplines to measure the properties of light emanating from astronomical objects, including Earth itself.

    Mahmooda Sultana, a research engineer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, now is collaborating with Moungi Bawendi, a chemistry professor at the Cambridge-based Massachusetts Institute of Technology, or MIT, to develop a prototype imaging spectrometer based on the emerging quantum-dot technology that Bawendi’s group pioneered.

    NASA’s Center Innovation Fund, which supports potentially trailblazing, high-risk technologies, is funding the effort.

    Introducing Quantum Dots

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    This illustration shows how a device prints the quantum dot filters that absorb different wavelengths of light depending on their size and composition. The emerging technology could give scientists a more flexible, cost-effective approach for developing spectrometers, a commonly used instrument. Credits: O’Reilly Science Art

    Quantum dots are a type of semiconductor nanocrystal discovered in the early 1980s. Invisible to the naked eye, the dots have proven in testing to absorb different wavelengths of light depending on their size, shape, and chemical composition. The technology is promising to applications that rely on the analysis of light, including smartphone cameras, medical devices, and environmental-testing equipment.

    “This is as novel as it gets,” Sultana said, referring to the technology that she believes could miniaturize and potentially revolutionize space-based spectrometers, particularly those used on uninhabited aerial vehicles and small satellites. “It really could simplify instrument integration.”

    Absorption spectrometers, as their name implies, measure the absorption of light as a function of frequency or wavelength due to its interaction with a sample, such as atmospheric gases.

    After passing through or interacting with the sample, the light reaches the spectrometer. Traditional spectrometers use gratings, prisms, or interference filters to split the light into its component wavelengths, which their detector pixels then detect to produce spectra. The more intense the absorption in the spectra, the greater the presence of a specific chemical.

    While space-based spectrometers are getting smaller due to miniaturization, they still are relatively large, Sultana said. “Higher-spectral resolution requires long optical paths for instruments that use gratings and prisms. This often results in large instruments. Whereas here, with quantum dots that act like filters that absorb different wavelengths depending on their size and shape, we can make an ultra-compact instrument. In other words, you could eliminate optical parts, like gratings, prisms, and interference filters.”

    Just as important, the technology allows the instrument developer to generate nearly an unlimited number of different dots. As their size decreases, the wavelength of the light that the quantum dots will absorb decreases. “This makes it possible to produce a continuously tunable, yet distinct, set of absorptive filters where each pixel is made of a quantum dot of a specific size, shape, or composition. We would have precise control over what each dot absorbs. We could literally customize the instrument to observe many different bands with high-spectral resolution.”

    Prototype Instrument Under Development

    With her NASA technology-development support, Sultana is working to develop, qualify through thermal vacuum and vibration tests, and demonstrate a 20-by-20 quantum-dot array sensitive to visible wavelengths needed to image the sun and the aurora. However, the technology easily can be expanded to cover a broader range of wavelengths, from ultraviolet to mid-infrared, which may find many potential space applications in Earth science, heliophysics, and planetary science, she said.

    Under the collaboration, Sultana is developing an instrument concept particularly for a CubeSat application and MIT doctoral student Jason Yoo is investigating techniques for synthesizing different precursor chemicals to create the dots and then printing them onto a suitable substrate. “Ultimately, we would want to print the dots directly onto the detector pixels,” she said.

    “This is a very innovative technology,” Sultana added, conceding that it is very early in its development. “But we’re trying to raise its technology-readiness level very quickly. Several space-science opportunities that could benefit are in the pipeline.”

    For more Goddard technology news, go to: http://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

    See the full article here.

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 5:04 pm on February 8, 2017 Permalink | Reply
    Tags: Ion escape, NASA Goddard, Oxygen escape, , Proxima b is subjected to torrents of X-ray and extreme ultraviolet radiation from superflares occurring roughly every two hours., , Stellar eruptions such as flares and coronal mass ejections – collectively called space weather, We have pessimistic results for planets around young red dwarfs in this study   

    From Goddard: “NASA Finds Planets of Red Dwarf Stars May Face Oxygen Loss in Habitable Zones” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Feb. 8, 2017
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    3
    Credit: NASA

    The search for life beyond Earth starts in habitable zones, the regions around stars where conditions could potentially allow liquid water – which is essential for life as we know it – to pool on a planet’s surface. New NASA research suggests some of these zones might not actually be able to support life due to frequent stellar eruptions – which spew huge amounts of stellar material and radiation out into space – from young red dwarf stars.

    Now, an interdisciplinary team of NASA scientists wants to expand how habitable zones are defined, taking into account the impact of stellar activity, which can threaten an exoplanet’s atmosphere with oxygen loss. This research was published in The Astrophysical Journal Letters on Feb. 6, 2017.

    “If we want to find an exoplanet that can develop and sustain life, we must figure out which stars make the best parents,” said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re coming closer to understanding what kind of parent stars we need.”

    To determine a star’s habitable zone, scientists have traditionally considered how much heat and light the star emits. Stars more massive than our sun produce more heat and light, so the habitable zone must be farther out. Smaller, cooler stars yield close-in habitable zones.

    But along with heat and visible light, stars emit X-ray and ultraviolet radiation, and produce stellar eruptions such as flares and coronal mass ejections – collectively called space weather. One possible effect of this radiation is atmospheric erosion, in which high-energy particles drag atmospheric molecules – such as hydrogen and oxygen, the two ingredients for water – out into space. Airapetian and his team’s new model for habitable zones now takes this effect into account.


    In this artist’s concept, X-ray and extreme ultraviolet light from a young red dwarf star cause ions to escape from an exoplanet’s atmosphere. Scientists have developed a model that estimates the oxygen ion escape rate on planets around red dwarfs, which plays an important role in determining an exoplanet’s habitability.
    Credits: NASA Goddard/Conceptual Image Lab, Michael Lentz, animator/Genna Duberstein, producer

    The search for habitable planets often hones in on red dwarfs, as these are the coolest, smallest and most numerous stars in the universe – and therefore relatively amenable to small planet detection.

    “On the downside, red dwarfs are also prone to more frequent and powerful stellar eruptions than the sun,” said William Danchi, a Goddard astronomer and co-author of the paper. “To assess the habitability of planets around these stars, we need to understand how these various effects balance out.”

    Another important habitability factor is a star’s age, say the scientists, based on observations they’ve gathered from NASA’s Kepler mission. Every day, young stars produce superflares, powerful flares and eruptions at least 10 times more powerful than those observed on the sun. On their older, matured counterparts resembling our middle-aged sun today, such superflares are only observed once every 100 years.

    “When we look at young red dwarfs in our galaxy, we see they’re much less luminous than our sun today,” Airapetian said. “By the classical definition, the habitable zone around red dwarfs must be 10 to 20 times closer-in than Earth is to the sun. Now we know these red dwarf stars generate a lot of X-ray and extreme ultraviolet emissions at the habitable zones of exoplanets through frequent flares and stellar storms.”

    Superflares cause atmospheric erosion when high-energy X-ray and extreme ultraviolet emissions first break molecules into atoms and then ionize atmospheric gases. During ionization, radiation strikes the atoms and knocks off electrons. Electrons are much lighter than the newly formed ions, so they escape gravity’s pull far more readily and race out into space.

    Opposites attract, so as more and more negatively charged electrons are generated, they create a powerful charge separation that lures positively charged ions out of the atmosphere in a process called ion escape.

    “We know oxygen ion escape happens on Earth at a smaller scale since the sun exhibits only a fraction of the activity of younger stars,” said Alex Glocer, a Goddard astrophysicist and co-author of the paper. “To see how this effect scales when you get more high-energy input like you’d see from young stars, we developed a model.”

    The model estimates the oxygen escape on planets around red dwarfs, assuming they don’t compensate with volcanic activity or comet bombardment. Various earlier atmospheric erosion models indicated hydrogen is most vulnerable to ion escape. As the lightest element, hydrogen easily escapes into space, presumably leaving behind an atmosphere rich with heavier elements such as oxygen and nitrogen.

    But when the scientists accounted for superflares, their new model indicates the violent storms of young red dwarfs generate enough high-energy radiation to enable the escape of even oxygen and nitrogen – building blocks for life’s essential molecules.

    “The more X-ray and extreme ultraviolet energy there is, the more electrons are generated and the stronger the ion escape effect becomes,” Glocer said. “This effect is very sensitive to the amount of energy the star emits, which means it must play a strong role in determining what is and is not a habitable planet.”

    Considering oxygen escape alone, the model estimates a young red dwarf could render a close-in exoplanet uninhabitable within a few tens to a hundred million years. The loss of both atmospheric hydrogen and oxygen would reduce and eliminate the planet’s water supply before life would have a chance to develop.

    “The results of this work could have profound implications for the atmospheric chemistry of these worlds,” said Shawn Domagal-Goldman, a Goddard space scientist not involved with the study. “The team’s conclusions will impact our ongoing studies of missions that would search for signs of life in the chemical composition of those atmospheres.”

    Modeling the oxygen loss rate is the first step in the team’s efforts to expand the classical definition of habitability into what they call space weather-affected habitable zones. When exoplanets orbit a mature star with a mild space weather environment, the classical definition is sufficient. When the host star exhibits X-ray and extreme ultraviolet levels greater than seven to 10 times the average emissions from our sun, then the new definition applies. The team’s future work will include modeling nitrogen escape, which may be comparable to oxygen escape since nitrogen is just slightly lighter than oxygen.

    The new habitability model has implications for the recently discovered planet orbiting the red dwarf Proxima Centauri, our nearest stellar neighbor. Airapetian and his team applied their model to the roughly Earth-sized planet, dubbed Proxima b, which orbits Proxima Centauri 20 times closer than Earth is to the sun.

    Considering the host star’s age and the planet’s proximity to its host star, the scientists expect that Proxima b is subjected to torrents of X-ray and extreme ultraviolet radiation from superflares occurring roughly every two hours. They estimate oxygen would escape Proxima b’s atmosphere in 10 million years. Additionally, intense magnetic activity and stellar wind – the continuous flow of charged particles from a star – exacerbate already harsh space weather conditions. The scientists concluded that it’s quite unlikely Proxima b is habitable.

    “We have pessimistic results for planets around young red dwarfs in this study, but we also have a better understanding of which stars have good prospects for habitability,” Airapetian said. “As we learn more about what we need from a host star, it seems more and more that our sun is just one of those perfect parent stars, to have supported life on Earth.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 3:14 pm on February 8, 2017 Permalink | Reply
    Tags: Archean Earth, NASA Goddard, NASA Team Looks to Ancient Earth First to Study Hazy Exoplanets   

    From Goddard: “NASA Team Looks to Ancient Earth First to Study Hazy Exoplanets” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Feb. 8, 2017
    Elizabeth Zubritsky
    elizabeth.a.zubritsky@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Md.

    For astronomers trying to understand which distant planets might have habitable conditions, the role of atmospheric haze has been hazy. To help sort it out, a team of researchers has been looking to Earth – specifically Earth during the Archean era, an epic 1-1/2-billion-year period early in our planet’s history.

    Earth’s atmosphere seems to have been quite different then, probably with little available oxygen but high levels of methane, ammonia and other organic chemicals. Geological evidence suggests that haze might have come and gone sporadically from the Archean atmosphere – and researchers aren’t quite sure why. The team reasoned that a better understanding of haze formation during the Archean era might help inform studies of hazy earthlike exoplanets.

    “We like to say that Archean Earth is the most alien planet we have geochemical data for,” said Giada Arney of NASA’s Goddard Spaceflight Center in Greenbelt, Maryland, and a member of the NASA Astrobiology Institute’s Virtual Planetary Laboratory based at the University of Washington, Seattle. Arney is the lead author of two related papers published by the team.

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    When haze built up in the atmosphere of Archean Earth, the young planet might have looked like a pale orange dot from a distance. A team led by Goddard scientists thinks the haze was self-limiting, cooling the surface by about 36 degrees Fahrenheit (20 Kelvins) – not enough to cause runaway glaciation. The team’s modeling suggests that atmospheric haze might be helpful for identifying earthlike exoplanets that could be habitable. Credits: NASA’s Goddard Space Flight Center/Francis Reddy

    In the best case, haze in a planet’s atmosphere could serve up a smorgasbord of carbon-rich, or organic, molecules that could be transformed by chemical reactions into precursor molecules for life. Haze also might screen out much of the harmful UV radiation that can break down DNA.

    In the worst case, haze could become so thick that very little light gets through. In this situation, the surface might get so cold it freezes completely. If a very thick haze occurred on Archean Earth, it might have had a profound effect, because when the era began roughly four billion years ago, the sun was fainter, emitting perhaps 80 percent of the light that it does now.

    Arney and her colleagues put together sophisticated computer modeling to look at how haze affected the surface temperature of Archean Earth and, in turn, how the temperature influenced the chemistry in the atmosphere.

    The new modeling indicates that as the haze got thicker, less sunlight would have gotten through, inhibiting the types of sunlight-driven chemical reactions needed to form more haze. This would lead to the shutdown of haze-formation chemistry, preventing the planet from undergoing runaway glaciation due to a very thick haze.

    The team calls this self-limiting haze, and their work is the first to make the case that this is what occurred on Archean Earth – a finding published in the November 2016 issue of the journal Astrobiology. The researchers concluded that self-limiting haze could have cooled Archean Earth by about 36 degrees Fahrenheit (20 Kelvins) – enough to make a difference but not to freeze the surface completely.

    “Our modeling suggests that a planet like hazy Archean Earth orbiting a star like the young sun would be cold,” said Shawn Domagal-Goldman, a Goddard scientist and a member of the Virtual Planetary Laboratory. “But we’re saying it would be cold like the Yukon in winter, not cold like modern-day Mars.”

    Such a planet might be considered habitable, even if the mean global temperature is below freezing, as long as there is some liquid water on the surface.

    In subsequent modeling, Arney and her colleagues looked at the effects of haze on planets that are like Archean Earth but orbiting several kinds of stars.

    “The parent star controls whether a haze is more likely to form, and that haze can have multiple impacts on a planet’s habitability,” said co-author Victoria Meadows, the principal investigator for the Virtual Planetary Laboratory and an astronomy professor at the University of Washington.

    It looks as if the Archean Earth hit a sweet spot where the haze served as a sunscreen layer for the planet. If the sun had been a bit warmer, as it is today, the modeling suggests the haze particles would have been larger – a result of temperature feedbacks influencing the chemistry – and would have formed more efficiently, but still would have offered some sun protection.

    The same wasn’t true in all cases. The modeling showed that some stars produce so much UV radiation that haze cannot form. Haze did not cool planets orbiting all types of stars equally, either, according to the team’s results. Dim stars, such as M dwarfs, emit most of their energy at wavelengths that pass right through atmospheric haze; in the simulations, these planets experience little cooling from haze, so they benefit from haze’s UV shielding without a major drop in temperature.

    For the right kind of star, though, the presence of haze in a planet’s atmosphere could help flag that world as a good candidate for closer study. The team’s simulations indicated that, for some instruments planned for future space telescopes, the spectral signature of haze would appear stronger than the signatures for some atmospheric gases, such as methane. These findings are available in the Astrophysical Journal as of Feb. 8, 2017.

    “Haze may turn out to be very helpful as we try to narrow down which exoplanets are the most promising for habitability,” said Arney.

    For more information about the NASA Astrobiology Institute, visit https://nai.nasa.gov/

    See the full article here.

    Please help promote STEM in your local schools.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard campus
    NASA/Goddard Campus
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  • richardmitnick 4:01 pm on January 6, 2017 Permalink | Reply
    Tags: HD 172555, Hubble Detects 'Exocomets' Taking the Plunge into a Young Star, , NASA Goddard   

    From Hubble: “Hubble Detects ‘Exocomets’ Taking the Plunge into a Young Star” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble Telescope

    Jan 6, 2017
    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Carol Grady
    Eureka Scientific Inc., Oakland, California,
    and Goddard Space Flight Center, Greenbelt, Maryland
    301-286-3748
    carol.a.grady@nasa.gov

    1

    Interstellar forecast for a nearby star: Raining comets! NASA’s Hubble Space Telescope has discovered comets plunging into the star HD 172555, which is a youthful 23 million years old and resides 95 light-years from Earth.

    The exocomets — comets outside our solar system — were not directly seen around the star, but their presence was inferred by detecting gas that is likely the vaporized remnants of their icy nuclei.

    HD 172555 represents the third extrasolar system where astronomers have detected doomed, wayward comets. All of these systems are young, under 40 million years old.

    The presence of these doomed comets provides circumstantial evidence for “gravitational stirring” by an unseen Jupiter-size planet, where comets deflected by the massive object’s gravity are catapulted into the star. These events also provide new insights into the past and present activity of comets in our solar system. It’s a mechanism where infalling comets could have transported water to Earth and the other inner planets of our solar system.

    Astronomers have found similar plunges in our own solar system. Sun-grazing comets routinely fall into our sun. “Seeing these sun-grazing comets in our solar system and in three extrasolar systems means that this activity may be common in young star systems,” said study leader Carol Grady of Eureka Scientific Inc., in Oakland, California, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This activity at its peak represents a star’s active teenage years. Watching these events gives us insight into what probably went on in the early days of our solar system, when comets were pelting the inner solar system bodies, including Earth. In fact, these star-grazing comets may make life possible, because they carry water and other life-forming elements, such as carbon, to terrestrial planets.”

    Grady will present her team’s results Jan. 6 at the winter meeting of the American Astronomical Society in Grapevine, Texas.

    The star is part of the Beta Pictoris Moving Group, a collection of stars born from the same stellar nursery.

    3
    Beta Pictoris Moving Group. http://astronomyonline.org/Exoplanets/ExoplanetDynamics.asp#I4

    It is the second group member found to harbor such comets. Beta Pictoris, the group’s namesake, also is feasting on exocomets travelling too close. A young gas-giant planet has been observed in that star’s vast debris disk.

    The Beta Pictoris Moving Group is important to study because it is the closest collection of young stars to Earth. At least 37.5 percent of the more massive stars in the group either have a directly imaged planet, such as 51 Eridani b in the 51 Eridani system, or infalling star-grazing bodies, or, in the case of Beta Pictoris, both types of objects. The grouping is around the age where it should be building terrestrial planets, Grady said.

    A team of French astronomers first discovered exocomets transiting HD 172555 in archival data gathered between 2004 and 2011 by the European Southern Observatory’s HARPS (High Accuracy Radial velocity Planet Searcher) spectrograph. A spectrograph divides light into its component colors, allowing astronomers to detect an object’s chemical makeup. The HARPS spectrograph detected the chemical fingerprints of calcium imprinted in the starlight, evidence that comet-like objects were falling into the star.

    As a follow-up to that discovery, Grady’s team used Hubble’s Space Telescope Imaging Spectrograph (STIS) and the Cosmic Origins Spectrograph (COS) in 2015 to conduct a spectrographic analysis in ultraviolet light, which allows Hubble to identify the signature of certain elements. Hubble made two observations, separated by six days.

    Hubble detected silicon and carbon gas in the starlight. The gas was moving at about 360,000 miles per hour across the face of the star. The most likely explanation for the speedy gas is that Hubble is seeing material from comet-like objects that broke apart after streaking across the star’s disk.

    The gaseous debris from the disintegrating comets is vastly dispersed in front of the star. “As transiting features go, this vaporized material is easy to see because it contains very large structures,” Grady said. “This is in marked contrast to trying to find a small, transiting exoplanet, where you’re looking for tiny dips in the star’s light.”

    Hubble gleaned this information because the HD 172555 debris disk surrounding the star is viewed close to edge-on through the disk, giving the telescope a clear view of comet activity.

    Grady’s team hopes to use STIS again in follow-up observations to look for oxygen and hydrogen, which would confirm the identity of the disintegrating objects as comets.

    “Hubble shows that these star-grazers look and move like comets, but until we determine their composition, we cannot confirm they are comets,” Grady said. “We need additional data to establish whether our star-grazers are icy like comets or more rocky like asteroids.”

    See the full article here .

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 9:57 am on January 5, 2017 Permalink | Reply
    Tags: , , , , NASA Goddard, ,   

    From NASA: “NASA Selects Two Missions to Explore the Early Solar System” 

    NASA image
    NASA

    Jan. 4, 2017
    Dwayne Brown
    dwayne.c.brown@nasa.gov
    Headquarters, Washington
    202-358-1726

    Laurie Cantillo
    laura.l.cantillo@nasa.gov
    Headquarters, Washington
    202-358-1077

    1
    (Left) An artist’s conception of the Lucy spacecraft flying by the Trojan Eurybates – one of the six diverse and scientifically important Trojans to be studied. Trojans are fossils of planet formation and so will supply important clues to the earliest history of the solar system. (Right) Psyche, the first mission to the metal world 16 Psyche will map features, structure, composition, and magnetic field, and examine a landscape unlike anything explored before. Psyche will teach us about the hidden cores of the Earth, Mars, Mercury and Venus.
    Credits: SwRI and SSL/Peter Rubin

    NASA has selected two missions that have the potential to open new windows on one of the earliest eras in the history of our solar system – a time less than 10 million years after the birth of our sun. The missions, known as Lucy and Psyche, were chosen from five finalists and will proceed to mission formulation, with the goal of launching in 2021 and 2023, respectively.

    “Lucy will visit a target-rich environment of Jupiter’s mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that’s never been visited before,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “This is what Discovery Program missions are all about – boldly going to places we’ve never been to enable groundbreaking science.”


    Access mp4 video here .

    Lucy, a robotic spacecraft, is scheduled to launch in October 2021. It’s slated to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.

    “This is a unique opportunity,” said Harold F. Levison, principal investigator of the Lucy mission from the Southwest Research Institute in Boulder, Colorado. “Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins.”

    Lucy will build on the success of NASA’s New Horizons mission to Pluto and the Kuiper Belt, using newer versions of the RALPH and LORRI science instruments that helped enable the mission’s achievements.

    NASA/New Horizons spacecraft
    NASA/New Horizons spacecraft

    Kuiper Belt. Minor Planet Center
    Kuiper Belt. Minor Planet Center

    Several members of the Lucy mission team also are veterans of the New Horizons mission. Lucy also will build on the success of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team.

    NASA OSIRIS-REx Spacecraft
    NASA OSIRIS-REx Spacecraft

    The Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the sun than is the Earth. This asteroid measures about 130 miles (210 kilometers) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be comprised mostly of metallic iron and nickel, similar to Earth’s core. Scientists wonder whether Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.

    The mission will help scientists understand how planets and other bodies separated into their layers – including cores, mantles and crusts – early in their histories.

    “This is an opportunity to explore a new type of world – not one of rock or ice, but of metal,” said Psyche Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. “16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space.”

    Psyche, also a robotic mission, is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025.

    In addition to selecting the Lucy and Psyche missions for formulation, the agency will extend funding for the Near Earth Object Camera (NEOCam) project for an additional year. The NEOCam space telescope is designed to survey regions of space closest to Earth’s orbit, where potentially hazardous asteroids may be found.

    “These are true missions of discovery that integrate into NASA’s larger strategy of investigating how the solar system formed and evolved,” said NASA’s Planetary Science Director Jim Green. “We’ve explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun. Lucy will observe primitive remnants from farther out in the solar system, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold.”

    Discovery Program class missions like these are relatively low-cost, their development capped at about $450 million. They are managed for NASA’s Planetary Science Division by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama. The missions are designed and led by a principal investigator, who assembles a team of scientists and engineers, to address key science questions about the solar system.

    The Discovery Program portfolio includes 12 prior selections such as the MESSENGER mission to study Mercury, the Dawn mission to explore asteroids Vesta and Ceres, and the InSight Mars lander, scheduled to launch in May 2018.

    NASA’s other missions to asteroids began with the NEAR orbiter of asteroid Eros, which arrived in 2000, and continues with Dawn, which orbited Vesta and now is in an extended mission phase at Ceres. The OSIRIS-REx mission, which launched on Sept. 8, 2016, is speeding toward a 2018 rendezvous with the asteroid Bennu, and will deliver a sample back to Earth in 2023. Each mission focuses on a different aspect of asteroid science to give scientists the broader picture of solar system formation and evolution.

    Read more about NASA’s Discovery Program and missions at:

    https://discovery.nasa.gov/missions.cfml

    See the full article here .

    Please help promote STEM in your local schools.

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    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 4:29 pm on January 4, 2017 Permalink | Reply
    Tags: , , NASA Goddard, Sophie Nowicki,   

    From Goddard: Women in STEM – “Sophie Nowicki – Hot on Glaciology “ 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Jan. 4, 2017
    Elizabeth M. Jarrell
    NASA Goddard Space Flight Center

    1
    Sophie Nowicki. Credits: NASA/W. Hrybyk.

    Name: Sophie Nowicki
    Formal Job Classification: Physical Scientist
    Organization: Code 615, Cryospheric Sciences Laboratory, Earth Sciences Division, Sciences and Exploration Directorate

    What do you do and what is most interesting about your role here at Goddard? How do you help support Goddard’s mission?

    I’m a glaciologist and I study the big ice sheets of Greenland and Antarctica. I want to understand how in the future they will evolve and contribute to sea level change. I use my models together with NASA’s climate models to make global projections of future sea levels.

    I use data collected by NASA in my models to check how the models compare to the real world. For example, I use data from airborne observations from Operation IceBridge and data from Ice, Cloud, and land Elevation (ICESat) satellite and the Gravity Recovery and Climate Experiment (GRACE) satellite.

    NASA/Grace
    “NASA/Grace

    Operation IceBridge is an airborne campaign that takes lots of different measurements, including the bedrock and the ice elevation in and around Greenland and Antarctica. ICESat was a satellite that measured ice sheet elevation of the Greenland and Antarctic. GRACE is a satellite that measures the mass change of the Greenland and Antarctic ice sheets.

    How do use your numerical models in conjunction with the climate models?

    Our numerical models add a new capability to NASA’s existing climate models because the climate models now include interactive ice sheets. We also modified the snow models that sit between the atmosphere and the ice sheets. This allows us to better capture the surface conditions over the ice sheets such as the snow melting identified by the satellites or the surface temperature over the ice sheets.

    We work with a tremendous amount of data. We assimilate all this data and make projections using NASA’s two supercomputers. One is at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the other is at NASA’s Goddard Institute for Space Studies (GISS) in New York City.

    Do you work both at Goddard and at GISS?

    Yes, but I physically spend most of my time in Greenbelt. I don’t have to go to GISS in person to do my work. The great thing about technology is that you don’t have to be in the same physical space to work with others. I have a post-doctoral fellow at GISS and we communicate constantly via Skype, emails and the phone. Both of us use the same supercomputer. My post-doctoral fellow also comes to Goddard a few times a year plus we meet at conferences throughout the year.

    Do you lead climate model teams at Goddard?

    I lead a team based at Goddard called the Interdisciplinary Science Team (IDS). We look at the recent changes in the Arctic to understand the impact and feedback of recent ice melts. Some of the changes we look at are the sea ice, clouds and aerosols and how these affect surface conditions on the Greenland ice sheet. We also try to understand how the increase in melting at the surface of the ice sheet changes the ocean, via freshening (change in the amount of salt in the water) for example, or how changes in sea ice or fresh water from the ice sheet affect phytoplankton production.

    Are you involved with teams at an agency level?

    I’m part of the NASA Sea Level Change Team, which has members from NASA centers and also from U.S. universities. Our goal is to understand how sea level is changing and better communicate that information to the public. The website is: https://sealevel.nasa.gov/

    Do you collaborate internationally?

    I travel internationally a few times a year, mainly to England and France. I co-lead an international effort called Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6, http://www.climate-cryosphere.org/activities/targeted/ismip6). Our steering committee includes eight other scientists and our members include scientists from the U.S., Japan, England, France, Denmark, Germany, Belgium and Russia.

    ISMIP6’s goal is to make better projections of global sea level rise. My role is to coordinate the effort and set the big picture. Our participants work with approximately 10 different global climate models that all include an interactive ice sheet component or will soon include this capability. We also have about twenty ice sheet models that are run outside of climate models. We will be combining the simulations from all thirty models. Our final products can be maps of future sea levels due to the ice sheets or numbers associated with possible future sea levels.

    Are your group’s projections incorporated into an international report?

    Yes, our group’s work becomes part of the International Panel on Climate Change’s report, which generally comes out every five years. Their next report, the Sixth Assessment Report (AR6), is planned for 2022. ISMIP6 is the first time that a large coordinated effort focusing on ice sheet and climate models will contribute to the IPCC report.

    Did you always want to be a scientist?

    Although both are now retired, my father is an American environmental scientist and my mother is a French environmental scientist. I wanted to be an artist or an architect, but my parents encouraged me to do science. For me, art and science are quite similar as they both require a lot of creativity.

    Where were you educated?

    I was born in northern France. I went to the University of Edinburgh in Scotland for an undergraduate degree in geophysics and a master’s degree in remote sensing and image processing. I then went to the University College London for a doctorate and post-graduate studies in glaciology.

    How did you come to work at Goddard?

    I was at a scientific conference in St. Petersburg, Russia, where I met Jay Zwally, a Goddard glaciologist. He liked my work in London and told me about Goddard. He suggested that I come for an interview. I did and I got the job. The lesson that I learned is that you never know who you are going to meet and what opportunities may come from that meeting.

    Do you have a mentor?

    My unofficial mentor is Gavin Schmidt, who is originally from England. He is a brilliant climate scientist and an amazing science communicator. When I need some advice about science or communicating, I always ask him what he thinks. When I started ISMIP6, Gavin shared with me lots of suggestions for starting and leading such an enormous international effort.

    How many post-doctoral fellows do you mentor?

    In addition to my fellow at GISS, I am currently mentoring one fellow from the NASA Post-doctoral Fellow program and one researcher at the University of Maryland. I also mentor some of the young scientists on the IDS team. I’m hoping to continue mentoring two scientists who just finished the NASA Fellow program with me.

    I always tell them: Whatever you do, do your best, as you never know who will notice.

    In 2014, I received a Robert H. Goddard Exceptional Achievement for Mentoring award for “attracting and mentoring talented students and postdocs into the challenging field of numerical modeling to improve our understanding of global climate and sea level rise.” It was such a surprise to receive this award, and I felt very fortunate that young scientists wanted to come and work with me. It is because of them that I got this award.

    What kind of art do you want to do when you have more time?

    One day, I still want to be an artist. I would like to return to acrylics painting. I love the style of Henri Matisse. I would also like to get back to making beaded jewelry. For now, my time at home is spent with our two young boys and puppy. My husband is also a scientist, who does research and teaches, so between our work and family life, we do not have much free time.

    See the full article here .

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.
    NASA Goddard campus
    NASA/Goddard Campus
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  • richardmitnick 2:18 pm on December 15, 2016 Permalink | Reply
    Tags: 1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile", , Lake Tekapo, NASA Goddard, , New Zealand, University of Canterbury Mt John Observatory   

    From Goddard: “Microlensing Study Suggests Most Common Outer Planets Likely Neptune-mass” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Dec. 15, 2016
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Maryland

    A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems. The study provides the first indication of the types of planets waiting to be found far from a host star, where scientists suspect planets form most efficiently.


    Neptune-mass worlds are likely the most common type in the outer realms of planetary systems
    Credits: NASA’s Goddard Space Flight Center

    1
    University of Canterbury Mt John Observatory, Lake Tekapo, New Zealand

    “We’ve found the apparent sweet spot in the sizes of cold planets. Contrary to some theoretical predictions, we infer from current detections that the most numerous have masses similar to Neptune, and there doesn’t seem to be the expected increase in number at lower masses,” said lead scientist Daisuke Suzuki, a post-doctoral researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland Baltimore County. “We conclude that Neptune-mass planets in these outer orbits are about 10 times more common than Jupiter-mass planets in Jupiter-like orbits.”

    Gravitational microlensing takes advantage of the light-bending effects of massive objects predicted by Einstein’s general theory of relativity.

    Gravitational microlensing
    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    It occurs when a foreground star, the lens, randomly aligns with a distant background star, the source, as seen from Earth. As the lensing star drifts along in its orbit around the galaxy, the alignment shifts over days to weeks, changing the apparent brightness of the source. The precise pattern of these changes provides astronomers with clues about the nature of the lensing star, including any planets it may host.

    2
    This graph plots 4,769 exoplanets and planet candidates according to their masses and relative distances from the snow line, the point where water and other materials freeze solid (vertical cyan line). Gravitational microlensing is particularly sensitive to planets in this region. Planets are shaded according to the discovery technique listed at right. Masses for unconfirmed planetary candidates from NASA’s Kepler mission are calculated based on their sizes. For comparison, the graph also includes the planets of our solar system.
    Credits: NASA’s Goddard Space Flight Center

    “We mainly determine the mass ratio of the planet to the host star and their separation,” said team member David Bennett, an astrophysicist at Goddard. “For about 40 percent of microlensing planets, we can determine the mass of the host star and therefore the mass of the planet.”

    More than 50 exoplanets have been discovered using microlensing compared to thousands detected by other techniques, such as detecting the motion or dimming of a host star caused by the presence of planets. Because the necessary alignments between stars are rare and occur randomly, astronomers must monitor millions of stars for the tell-tale brightness changes that signal a microlensing event.

    However, microlensing holds great potential. It can detect planets hundreds of times more distant than most other methods, allowing astronomers to investigate a broad swath of our Milky Way galaxy. The technique can locate exoplanets at smaller masses and greater distances from their host stars, and it’s sensitive enough to find planets floating through the galaxy on their own, unbound to stars.

    NASA’s Kepler and K2 missions have been extraordinarily successful in finding planets that dim their host stars, with more than 2,500 confirmed discoveries to date.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    This technique is sensitive to close-in planets but not more distant ones. Microlensing surveys are complementary, best probing the outer parts of planetary systems with less sensitivity to planets closer to their stars.

    “Combining microlensing with other techniques provides us with a clearer overall picture of the planetary content of our galaxy,” said team member Takahiro Sumi at Osaka University in Japan.

    From 2007 to 2012, the Microlensing Observations in Astrophysics (MOA) group, a collaboration between researchers in Japan and New Zealand, issued 3,300 alerts informing the astronomical community about ongoing microlensing events. Suzuki’s team identified 1,474 well-observed microlensing events, with 22 displaying clear planetary signals. This includes four planets that were never previously reported.

    To study these events in greater detail, the team included data from the other major microlensing project operating over the same period, the Optical Gravitational Lensing Experiment (OGLE), as well as additional observations from other projects designed to follow up on MOA and OGLE alerts.

    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile1.3 meter OGLE Warsaw telescope interior
    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile”

    From this information, the researchers determined the frequency of planets compared to the mass ratio of the planet and star as well as the distances between them. For a typical planet-hosting star with about 60 percent the sun’s mass, the typical microlensing planet is a world between 10 and 40 times Earth’s mass. For comparison, Neptune in our own solar system has the equivalent mass of 17 Earths.

    The results imply that cold Neptune-mass worlds are likely to be the most common types of planets beyond the so-called snow line, the point where water remained frozen during planetary formation. In the solar system, the snow line is thought to have been located at about 2.7 times Earth’s mean distance from the sun, placing it in the middle of the main asteroid belt today.

    3
    Neptune-mass exoplanets like the one shown in this artist’s rendering may be the most common in the icy regions of planetary systems. Beyond a certain distance from a young star, water and other substances remain frozen, leading to an abundant population of icy objects that can collide and form the cores of new planets. In the foreground, an icy body left over from this period drifts past the planet.
    Credits: NASA/Goddard/Francis Reddy

    A paper detailing the findings was published in The Astrophysical Journal on Dec. 13.

    “Beyond the snow line, materials that were gaseous closer to the star condense into solid bodies, increasing the amount of material available to start the planet-building process,” said Suzuki. “This is where we think planetary formation was most efficient, and it’s also the region where microlensing is most sensitive.”

    NASA’s Wide Field Infrared Survey Telescope (WFIRST), slated to launch in the mid-2020s, will conduct an extensive microlensing survey.

    NASA/WFIRST
    NASA/WFIRST

    Astronomers expect it will deliver mass and distance determinations of thousands of planets, completing the work begun by Kepler and providing the first galactic census of planetary properties.

    NASA’s Ames Research Center manages the Kepler and K2 missions for NASA’s Science Mission Directorate. The Jet Propulsion Laboratory (JPL) in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    WFIRST is managed at Goddard, with participation by JPL, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprising members from U.S. research institutions across the country.

    For more information on how NASA’s Kepler is working with ground-based efforts, including the MOA and OGLE groups, to search for planets using microlensing, please visit:

    https://www.nasa.gov/feature/ames/kepler/searching-for-far-out-and-wandering-worlds/

    See the full article here.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

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  • richardmitnick 8:30 am on December 13, 2016 Permalink | Reply
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    From JPL-Caltech: “Earth’s Magnetic Fields Could Track Ocean Heat: NASA” 

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    JPL-Caltech

    December 12, 2016
    News Media Contact
    Alan Buis
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-0474
    alan.buis@jpl.nasa.gov

    Patrick Lynch
    NASA Goddard Space Flight Center, Greenbelt, Md.
    757-897-2047
    patrick.lynch@nasa.gov

    Written by Kate Ramsayer, NASA Goddard Space Flight Center

    1
    NASA scientists are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean. Credit: NASA Goddard Space Flight Center

    As Earth warms, much of the extra heat is stored in the planet’s ocean — but monitoring the magnitude of that heat content is a difficult task.

    A surprising feature of the tides could help, however. Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

    As Earth warms, much of the extra heat is stored in the planet’s ocean — but monitoring the magnitude of that heat content is a difficult task.

    A surprising feature of the tides could help, however. Scientists at aNASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

    “If you’re concerned about understanding global warming, or Earth’s energy balance, a big unknown is what’s going into the ocean,” said Robert Tyler, a research scientist at Goddard. “We know the surfaces of the oceans are heating up, but we don’t have a good handle on how much heat is being stored deep in the ocean.”

    Despite the significance of ocean heat to Earth’s climate, it remains a variable that has substantial uncertainty when scientists measure it globally. Current measurements are made mainly by Argo floats, but these do not provide complete coverage in time or space. If it is successful, this new method could be the first to provide global ocean heat measurements, integrated over all depths, using satellite observations.

    Tyler’s method depends on several geophysical features of the ocean. Seawater is a good electrical conductor, so as saltwater sloshes around the ocean basins it causes slight fluctuations in Earth’s magnetic field lines. The ocean flow attempts to drag the field lines around, Tyler said. The resulting magnetic fluctuations are relatively small, but have been detected from an increasing number of events including swells, eddies, tsunamis and tides.

    “The recent launch of the European Space Agency’s Swarm satellites, and their magnetic survey, are providing unprecedented observational data of the magnetic fluctuations,” Tyler said. “With this comes new opportunities.”

    ESA/Swarm
    ESA/Swarm

    Researchers know where and when the tides are moving ocean water, and with the high-resolution data from the Swarm satellites, they can pick out the magnetic fluctuations due to these regular ocean movements.

    That’s where another geophysical feature comes in. The magnetic fluctuations of the tides depend on the electrical conductivity of the water — and the electrical conductivity of the water depends on its temperature.

    For Tyler, the question then is: “By monitoring these magnetic fluctuations, can we monitor the ocean temperature?”

    At the American Geophysical Union meeting in San Francisco this week, Tyler and collaborator Terence Sabaka, also at Goddard, presented the first results. They provide a key proof-of-concept of the method by demonstrating that global ocean heat content can be recovered from “noise-free” ocean tidal magnetic signals generated by a computer model. When they try to do this with the “noisy” observed signals, it doesn’t yet provide the accuracy needed to monitor changes in the heat content.

    But, Tyler said, there is much room for improvement in how the data are processed and modeled, and the Swarm satellites continue to collect magnetic data. This is a first attempt at using satellite magnetic data to monitor ocean heat, he said, and there is still much more to be done before the technique could successfully resolve this key variable. For example, by identifying fluctuations caused by other ocean movements, like eddies or other tidal components, scientists can extract even more information and get more refined measurements of ocean heat content and how it’s changing.

    More than 90 percent of the excess heat in the Earth system goes into the ocean, said Tim Boyer, a scientist with the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information. Scientists currently monitor ocean heat with shipboard measurements and Argo floats. While these measurements and others have seen a steady increase in heat since 1955, researchers still need more complete information, he said.

    “Even with the massive effort with the Argo floats, we still don’t have as much coverage of the ocean as we would really like in order to lower the uncertainties,” Boyer said. “If you’re able to measure global ocean heat content directly and completely from satellites, that would be fantastic.”

    Changing ocean temperatures have impacts that stretch across the globe. In Antarctica, floating sections of the ice sheet are retreating in ways that can’t be explained only by changes in atmospheric temperatures, said Catherine Walker, an ice scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

    She and her colleagues studied glaciers in Antarctica that lose an average of 6.5 to 13 feet (2 to 4 meters) of elevation per year. They looked at different options to explain the variability in melting — surrounding sea ice, winds, salinity, air temperatures — and what correlated most was influxes of warmer ocean water.

    “These big influxes of warm water come onto the continental shelf in some years and affect the rate at which ice melts,” Walker said. She and her colleagues are presenting the research at the AGU meeting.

    Walker’s team has identified an area on the Antarctic Peninsula where warmer waters may have infiltrated inland, under the ice shelf — which could have impacts on sea level rise.

    Float and ship measurements around Antarctica are scarce, but deep water temperature measurements can be achieved using tagged seals. That has its drawbacks, however: “It’s random, and we can’t control where they go,” Walker said. Satellite measurements of ocean heat content and temperatures would be very useful for the Southern Ocean, she added.

    Ocean temperatures also impact life in the ocean — from microscopic phytoplankton on up the food chain. Different phytoplankton thrive at different temperatures and need different nutrients.

    “Increased stratification in the ocean due to increased heating is going to lead to winners and losers within the phytoplankton communities,” said Stephanie Schollaert Uz, a scientist at Goddard.

    n research presented this week at AGU, she took a look 50 years back. Using temperature, sea level and other physical properties of the ocean, she generated a history of phytoplankton extent in the tropical Pacific Ocean, between 1958 and 2008. Looking over those five decades, she found that phytoplankton extent varied between years and decades. Most notably, during El Niño years, water currents and temperatures prevented phytoplankton communities from reaching as far west in the Pacific as they typically do.

    Digging further into the data, she found that where the El Niño was centered has an impact on phytoplankton. When the warmer waters of El Niño are centered over the Eastern Pacific, it suppresses nutrients across the basin, and therefore depresses phytoplankton growth more so than a central Pacific El Niño.

    “For the first time, we have a basin-wide view of the impact on biology of interannual and decadal forcing by many El Niño events over 50 years,” Uz said.

    As ocean temperatures impact processes across the Earth system, from climate to biodiversity, Tyler will continue to improve this novel magnetic remote sensing technique, to improve our future understanding of the planet.

    NASA collects data from space, air, land and sea to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

    See the full article here .

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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