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  • richardmitnick 12:57 pm on November 1, 2018 Permalink | Reply
    Tags: , , , , , , , , NASA TESS   

    From Many Worlds: “The Kepler Space Telescope Mission Is Ending But Its Legacy Will Keep Growing” 

    NASA NExSS bloc

    NASA NExSS

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    From Many Worlds

    2018-11-01
    Marc Kaufman

    NASA/Kepler Telescope

    As of October 2018, the planet-hunting spacecraft has been in space for nearly a decade. (NASA via AP)

    The Kepler Space Telescope is dead. Long live the Kepler.

    NASA officials announced on Tuesday that the pioneering exoplanet survey telescope — which had led to the identification of almost 2,700 exoplanets — had finally reached its end, having essentially run out of fuel. This is after nine years of observing, after a malfunctioning steering system required a complex fix and change of plants, and after the hydrazine fuel levels reached empty.

    While the sheer number of exoplanets discovered is impressive the telescope did substantially more: it proved once and for all that the galaxy is filled with planets orbiting distant stars. Before Kepler this was speculated, but now it is firmly established thanks to the Kepler run.

    It also provided data for thousands of papers exploring the logic and characteristics of exoplanets. And that’s why the Kepler will indeed live long in the world of space science.

    “As NASA’s first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington.

    “Not only did it show us how many planets could be out there, it sparked an entirely new and robust field of research that has taken the science community by storm. Its discoveries have shed a new light on our place in the universe, and illuminated the tantalizing mysteries and possibilities among the stars.”

    1
    The Kepler Space Telescope was focused on hunting for planets in this patch of the Milky Way. After two of its four spinning reaction wheels failed, it could no longer remain steady enough to stare that those distant stars but was reconfigured to look elsewhere and at a different angle for the K2 mission. (Carter Roberts/NASA)

    Kepler was initially the unlikely brainchild of William Borucki, its founding principal investigator who is now retired from NASA’s Ames Research Center in California’s Silicon Valley.

    3
    William Borucki, originally the main champion for the Kepler idea and later the principal investigator of the mission. His work at NASA went back to the Apollo days. (NASA)

    When he began thinking of designing and proposing a space telescope that could potentially tell us how common distant exoplanets were — and especially smaller terrestrial exoplanets like Earth – the science of extra solar planets was at a very different stage.

    “When we started conceiving this mission 35 years ago we didn’t know of a single planet outside our solar system,” Borucki said. “Now that we know planets are everywhere, Kepler has set us on a new course that’s full of promise for future generations to explore our galaxy.”

    The space telescope was launched in 2009. While Kepler did not find the first exoplanets — that required the work of astronomers using a different technique of observing based on the “wobble” of stars caused by orbiting planets — it did change the exoplanet paradigm substantially.

    Not only did it prove that exoplanets are common, it found that planets outnumber stars in our galaxy (which has hundreds of billions of those stars.)

    In addition it found that small, terrestrial-size planets are common as well, with some 20 to 50 percent of stars likely to have planets of that size and type. And what menagerie of planets it found out there.

    Among the greatest surprises: The Kepler mission provided data showing that the most common sized planets in the galaxy fall somewhere between Earth and Neptune, a type of planet that isn’t present in our solar system.

    It found solar systems of all sizes as well, including some with many planets (as many as eight) orbiting close to their host star.

    The discovery of these compact systems, generally orbiting a red dwarf star, raised questions about how solar systems form: Are these planets “born” close to their parent star, or do they form farther out and migrate in?

    So far, more than 2,500 peer-reviewed papers have been published using Kepler data, with substantial amounts of that data still unmined.

    Natalie Batalha was the project and mission scientist for Kepler for much of its run, and I asked her about its legacy.

    2
    Astrophysicist Natalie Batalha was the Kepler project and mission scientist for a decade. She left NASA recently for the University of California at Santa Cruz “to carry on the Kepler legacy” by creating an interdisciplinary center for the study of planetary habitability.

    “When I think of Kepler’s influence across all of astrophysics, I’m amazed at what such a simple experiment accomplished,” she wrote in an email. “You’d be hard-pressed to come up with a more boring mandate — to unblinkingly measure the brightnesses of the same stars for years on end. No beautiful images. No fancy spectra. No landscapes. Just dots in a scatter plot.

    “And yet time-domain astronomy exploded. We’d never looked at the Universe quite this way before. We saw lava worlds and water worlds and disintegrating planets and heart-beat stars and supernova shock waves and the spinning cores of stars and planets the age of the galaxy itself… all from those dots.”

    4
    The Kepler-62 system is but one of many solar systems detected by the space telescope. The planets within the green discs are in the habitable zones of the stars — where water could be liquid at times. (NASA)

    While Kepler provided remarkable answers to questions about the overall planetary makeup of our galaxy, it did not identify smaller planets that will be directly imaged, the evolving gold standard for characterizing exoplanets. The 150,000 stars that the telescope was observing were very distant, in the range of a few hundred to a few thousand light-years away. One light year is about 6 trillion (6,000,000,000,000) miles.

    Nonetheless, Kepler was able to detect the presence of a handful of Earth-sized planets in the habitable zones of their stars. The Kepler-62 system held one of them, and it is 1200 light-years away. In contrast, the four Earth-sized planets in the habitable zone of the much-studied Trappist-1 system are 39 light-years away.

    Kepler made its observations using the the transit technique, which looks for tiny dips in the amount of light coming from a star caused by the presence of a planet passing in front of the star. While the inference that exoplanets are ubiquitous came from Kepler results, the telescope was actually observing but a small bit of the sky. It has been estimated that it would require around 400 space telescopes like Kepler to cover the whole sky.

    What’s more, only planets whose orbits are seen edge-on from Earth can be detected via the transit method, and that rules out a vast number of exoplanets.

    The bulk of the stars that were selected for close Kepler observation were more or less sun-like, but a sampling of other stars occurred as well. One of the most important factors was brightness. Detecting minuscule changes in brightness caused by transiting planet is impossible if the star is too dim.

    Four years into the mission, after the primary mission objectives had been met, mechanical failures temporarily halted observations. The mission team was able to devise a fix, switching the spacecraft’s field of view roughly every three months. This enabled an extended mission for the spacecraft, dubbed K2, which lasted as long as the first mission and bumped Kepler’s count of surveyed stars up to more than 500,000.

    But it was inevitable that the mission would come to an end sooner rather than later because of that dwindling fuel supply, needed to keep the telescope properly pointed.

    Kepler cannot be refueled because NASA decided to place the telescope in an orbit around the sun that is well beyond the influence of the Earth and moon — to simplify operations and ensure an extremely quiet, stable environment for scientific observations. So Kepler was beyond the reach of any refueling vessel. The Kepler team compensated by flying considerably more fuel than was necessary to meet the mission objectives.

    The video below explains what will happen to the Kepler capsule once it is decommissioned. But a NASA release explains that the final commands “will be to turn off the spacecraft transmitters and disable the onboard fault protection that would turn them back on. While the spacecraft is a long way from Earth and requires enormous antennas to communicate with it, it is good practice to turn off transmitters when they are no longer being used, and not pollute the airwaves with potential interference.”

    And so Kepler will actually continue orbiting for many decades, just as its legacy will continue long after operations cease.

    Kepler’s follow-on exoplanet surveyor — the Transiting Exoplanet Survey Satellite or TESS — was launched this year and has begun sending back data.

    NASA/MIT TESS

    Its primary mission objective is to survey the brightest stars near the Earth for transiting exoplanets. The TESS satellite uses an array of wide-field cameras to survey some 85% of the sky, and is planned to last for two years.

    See the full article here .


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    Please help promote STEM in your local schools.

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    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.

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  • richardmitnick 4:53 pm on May 17, 2018 Permalink | Reply
    Tags: , , , , , NASA TESS, The future for TESS - an interview   

    From Kavli MIT Institute For Astrophysics and Space Research: “To Seek Out New Life: How the TESS Mission Will Accelerate the Hunt for Livable Alien Worlds” 

    KavliFoundation

    http://www.kavlifoundation.org/institutes

    Kavli MIT Institute of Astrophysics and Space Research

    From Kavli MIT Institute For Astrophysics and Space Research

    May 17, 2018

    Adam Hadhazy
    Spring 2018

    The just-launched Transiting Exoplanet Survey Satellite (TESS) could soon provide the breakthrough
    identification of dozens of potentially habitable exoplanets right in our cosmic backyard.

    NASA/TESS

    A NEW ERA IN THE SEARCH FOR EXOPLANETS—and the alien life they might host—has begun. Aboard a SpaceX rocket, the Transiting Exoplanet Survey Satellite (TESS) launched on April 18, 2018, at 6:51 PM EDT. The TESS mission, developed with support from The Kavli Foundation, is led by the Massachusetts Institute of Technology (MIT) and the MIT Kavli Institute for Astrophysics and Space Research.

    Over the next two years, TESS will scan the 200,000 or so nearest and brightest stars to Earth for telltale dimming caused when exoplanets cross their stars’ faces. Among the thousands of new worlds TESS is expected to discover should be hundreds ranging in size from about one to two times Earth. These small, mostly rocky planets will serve as prime targets for detailed follow-up observations by other telescopes in space and on the ground.

    The goal for those telescopes will be to characterize the newfound exoplanets’ atmospheres. The particular mixtures of gases in an atmosphere will reveal key clues about a world’s climate, history, and if it might even be hospitable to life.

    The Kavli Foundation spoke with two scientists on the TESS mission to get an inside look at its development and revolutionary science aim of finding the first “Earth twin” in the universe.

    The participants were:

    GREG BERTHIAUME – is the Instrument Manager for the TESS mission, in charge of ensuring the spacecraft’s cameras and other equipment will perform their science tasks. Berthiaume is based at the Massachusetts Institute of Technology’s (MIT) Lincoln Laboratory and he is also a member of the MIT Kavli Institute for Astrophysics and Space Research.

    DIANA DRAGOMIR – is an observational astronomer whose focus is on small exoplanets. Dragomir is a Hubble Postdoctoral Fellow at the MIT Kavli Institute for Astrophysics and Space Research.

    The following is an edited transcript of their roundtable discussion. The participants have been provided the opportunity to amend or edit their remarks.

    THE KAVLI FOUNDATION: Starting with the big picture, why is TESS important?

    DIANA DRAGOMIR: TESS is going to find thousands of exoplanets, which might not sound like a big deal, because we already know of nearly 4,000. But most of those discovered planets are too far away for us to do anything more than just know their size and that they are there. The difference is that TESS will be looking for planets around stars very close to us. When stars are closer to us, they’re also brighter from our point of view, and that helps us discover and study the planets around them much more easily.

    GREG BERTHIAUME: One of the things TESS is doing is helping to answer the fundamental question, “Is there other life in the universe?” People have been wondering that for thousands of years. Now TESS won’t answer that question directly, but it’s a step, just like Diana mentioned, on the path to getting us the data to see where there might be other life out there. That’s something we’ve been struggling with and questioning since we were able to come up with questions.

    TKF: What exactly do you expect TESS to find?

    Diana DragomirDiana Dragomir is an observational astronomer whose research focus is on small exoplanets. She is a Hubble Postdoctoral Fellow at the MIT Kavli Institute for Astrophysics and Space Research.

    DRAGOMIR: TESS will probably find 100 to 200 approximately Earth-size worlds, as well as thousands of more exoplanets all the way up to Jupiter in size.

    BERTHIAUME: We’re trying to find planets that are Earth analogs, meaning they’ll be Earth-like in their characteristics, such as size, mass, and so on. That means we want to find planets with atmospheres, with gravity similar to Earth’s. We want to find planets that are cool enough so water can be liquid on their surfaces, and not so cold that the water is frozen all the time. We call these “Goldilocks” planets, located in a star’s “habitable zone.” That’s really our target.

    DRAGOMIR: Exactly right. We want to find the first “Earth twin.” TESS will mainly find planets in the habitable zone of red dwarfs. These are stars a bit smaller and cooler than the Sun. A planet around a red dwarf can be located in an orbit closer to its star than it could be with a hotter star like our Sun and still maintain that nice, Goldilocks temperature. Closer orbits translate to more transits, or star crossings, which makes these red dwarf planets easier to find and study than planets around Sun-like stars.

    Astronomers are working hard on ways that we might push the TESS data and find some planets in the habitable zone of Sun-like stars, too. It’s challenging because those planets have longer orbital periods—years, that is—than close-in planets. That means we need a lot more observation time in order to detect enough transits of the planets across their stars to say we’ve definitely detected a planet. But we’re hopeful, so stay tuned!

    TKF: What do you need to see in order to deem any of the planets discovered by TESS as potentially habitable?

    DRAGOMIR: We want a planet to be close to Earth in size for all the reasons we just gave, but there’s a small problem with that. Those sorts of planets will probably have pretty small atmospheres, compared to how much rock makes up their bulk. And for most telescopes to be able to look at an atmosphere in detail, we actually need the planet to have a substantial atmosphere.

    This is because of a technique we use called transmission spectroscopy. It gathers the light from the star that has gone through the atmosphere of the planet when the planet is crossing the star. That light comes to us with a spectrum of the planet’s atmosphere imprinted on it, which we can analyze to identify the composition of the atmosphere. The more atmosphere there is, the more material there is that can imprint on the spectrum, giving us a bigger signal.

    If the light from the star is going through very little atmosphere, though, like we’d be looking at with an Earth twin, the signal would be very small. Based on what TESS finds, we’re therefore going to be starting with bigger planets that have a lot of atmosphere, and as we get better instruments, we’re going to move towards smaller and smaller planets with less atmosphere. It’s those latter planets which will more likely be habitable.

    BERTHIAUME: What we’re going to look for in the atmosphere are things like water vapor, oxygen, carbon dioxide—the standard gases we see in our atmosphere that life needs and life produces. We’re also going to try and measure the nasty things that aren’t compatible with life as we know it on Earth. For instance, it would be a bad thing for biology if there were too much ammonia in a world’s atmosphere. Hydrocarbons, like methane, would also be problematic in too high an abundance.

    TKF: Diana, your specialty is exoplanets smaller than Neptune—a planet four times bigger than Earth. What is our general knowledge about those kinds of worlds and how will TESS help with your research?

    DRAGOMIR: One thing we know about these planets is that they are extremely common compared to planets larger than Neptune. So that’s good. We therefore expect TESS to find lots and lots of planets smaller than Neptune for us to look at.

    Although small is bad for getting those atmospheric imprints we just talked about, if the stars are nearby and bright, we might still be able to get enough light for doing good studies. I’m hoping that we’ll get enough below Neptune-size that we’ll start looking at the atmospheres of “super-Earths,” which are planets twice the size of Earth or so. We don’t have any super-Earths in our solar system, so we’d love to get a closer look at one of these kinds of worlds. And just maybe, if we find a really, really good planetary candidate, we may be able to start looking at the atmosphere of an Earth-sized planet.

    With my research, one more thing TESS could really help with is figuring out the boundary between a very gassy planet like Neptune and a very rocky planet like Earth. We believe it’s mostly a matter of mass; have too much mass, and the planet stars to hold into a thick atmosphere. Right now, we’re not sure where that threshold is. And that matters so we know when a planet is rocky and potentially habitable, or gassy and not habitable.

    TKF: Greg, as the TESS Instrument Manager, a lot rides on your shoulders for the mission’s success. Can you tell us a bit about your job?

    BERTHIAUME: My job as instrument manager is different from a science job, for sure. My job was to make sure that all of the pieces, all the parts that go into the four flight cameras and the image processing hardware all play and work together and give us the great data that we need for Diana to go and continue to explore exoplanets. My personal role on the mission actually ends shortly after launch. Once we’ve demonstrated that the satellite provides the data that we expect, and we deal with any surprises that may come up, then I move on and data goes off to the science community.

    I definitely feel responsible for getting the quality of the data as high as it possibly can be. A lot of people worked really hard for years to build the cameras that are flying on TESS and it’s been great to be part of that team.

    TKF: New exoplanet missions like the European Space Agency’s Ariel and Plato satellites are slated to begin in the late 2020s. How might these future spacecraft complement and build on TESS’ body of work?

    DRAGOMIR: The great thing about TESS is that it’s going to give us a lot to choose from in terms of the best options for planets we’ll want to study. In that way, TESS will set the stage for Ariel’s mission, which is to deeply study the atmospheres of a select group of exoplanets.

    The Plato mission will be looking for planets that are habitable, but around bigger stars like the Sun, whereas TESS will focus on looking for habitable planets around smaller stars. I’m happy with that because I don’t want us to put all of our eggs in one basket by only looking at red dwarf stars with TESS. Planets around these red dwarfs are very exciting right now because they’re easier to study and they transit their stars more often, making them easier to find. But at the same time, red dwarfs tend to be much more active than the Sun. When a star is active, that means it often expels bursts of radiation called flares. These flares could be very damaging to a planet’s atmosphere and make the world uninhabitable.

    In the end, we of course live around a Sun-like star, and so far, we are the only “we” we know of in the universe. So for those reasons, it’s great to have Plato complementarily come along and find those planets around suns that TESS will probably not be able to find.

    TKF: When do you expect TESS’ first discoveries of brand new worlds to be reported?

    BERTHIAUME: First, it’s going to take a while to get TESS into its unique orbit. It’s the first time we’re putting a spacecraft in a new kind of far-ranging, highly elliptical orbit, where the gravity from the Earth and the Moon will keep TESS very stable, both from an orbit perspective and from a thermal perspective. So a big part of what’s going to happen over the first six weeks is just achieving that final orbit.

    Then there’s a period of time where there’ll be data collected to make sure the instruments are working as expected, as well as getting our data processing pipeline tuned up. I think we’ll start to see interesting results come out sometime this summer.

    TKF: Besides new worlds, what else might TESS reveal about the universe?

    2
    A set of flight camera electronics on one of the TESS cameras, developed by the MIT Kavli Institute for Astrophysics and Space Research (MKI). (Image: MIT Kavli Institute)

    DRAGOMIR: Because TESS is observing so much of the sky, it’s going to see lots of things that are happening in real-time, not just exoplanets crossing stars. As for those stars, we can learn a lot about their properties and even measure their masses quite precisely by doing asteroseismology with TESS. This technique involves tracking brightness changes as sound waves move through the interiors of stars—just like how seismic waves pass through the Earth’s rock and molten insides during earthquakes.

    We’ll also be studying the flaring activity of the stars, which as we spoke about earlier might make close-in, temperate planets around red dwarf stars uninhabitable.

    Moving up in size, scientists will want to search the TESS data for evidence of small black holes. These extreme objects, formed when colossal stars explode, can orbit normal stars that are still “alive,” so to speak. These systems will help us better understand how those black holes form and how they interact with companion stars.

    And then finally, going even bigger, TESS will look at galaxies called quasars. These ultra-bright galaxies are powered by supermassive black holes in their cores. TESS will help us monitor how quasars’ brightness changes, which we can link back to the dynamics of their black holes.

    TKF: The James Webb Space Telescope, hailed as the successor to the Hubble Space Telescope, has long been talked about as a primary instrument for doing the detailed follow-up observations on promising exoplanets found by TESS. However, James Webb’s launch, already delayed multiple times, just got pushed out yet another year, to 2020. How will the ongoing James Webb delays affect the TESS mission?

    DRAGOMIR: The James Webb delay is not so much of a problem because it actually gives us more time to collect great target planets with TESS. Before we can use James Webb to really observe candidate exoplanets and study their atmospheres, we first need to confirm the planets are real—that what we think are planets are not false positives caused, for instance, by stellar activity. That confirmation process takes weeks, using support observations from ground-based telescopes. It will then also take weeks to months to obtain the mass of the planets. We measure that by registering how much planets cause their host stars to experience slight “wobbles” in their motion over time, owing to the planets’ gravities, which are determined by their mass.

    Once you have that mass, plus the size of an exoplanet based on how much starlight it blocks during a TESS detection, you can measure its density and determine if it’s rocky or gaseous. With this information, it is then easier to decide which planets we want to prioritize, and the more we can make sense out of what James Webb will tell us about their atmospheres.

    TKF: Spacecraft sometimes have humorous or even profound extra elements built into them. One example: the “Golden Records” on the twin Voyager spacecraft, which contain images and sounds of life and civilization on Earth, including the Taj Mahal and birdsong. Are there any such items included on TESS? Any subtle maker’s marks or messages?

    BERTHIAUME: One of the things that’s flying along with TESS is a metal plaque that has the signatures of many of the people who worked on developing and building the spacecraft. That was an exciting thing for us.

    DRAGOMIR: That’s cool. I didn’t know that!

    BERTHIAUME: Also, NASA ran an international contest inviting people from around the world to submit drawings of what they thought exoplanets might look like. I know many children participated. All of those drawings were scanned onto a thumb drive and they’re flying along with TESS. The spacecraft’s orbit is stable for a century at least, so the plaque and the drawings will be in space for a long time!

    See the full article here .

    Please help promote STEM in your local schools.

    stem

    Stem Education Coalition

    Mission Statement

    The mission of the MIT Kavli Institute (MKI) for Astrophysics and Space Research is to facilitate and carry out the research programs of faculty and research staff whose interests lie in the broadly defined area of astrophysics and space research. Specifically, the MKI will

    Provide an intellectual home for faculty, research staff, and students engaged in space- and ground-based astrophysics
    Develop and operate space- and ground-based instrumentation for astrophysics
    Engage in technology development
    Maintain an engineering and technical core capability for enabling and supporting innovative research
    Communicate to students, educators, and the public an understanding of and an appreciation for the goals, techniques and results of MKI’s research.

    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 10:43 am on May 4, 2018 Permalink | Reply
    Tags: , , , NASA TESS, , ,   

    From MIT News: “Ushering in the next phase of exoplanet discovery” 

    MIT News
    MIT Widget

    MIT News

    May 3, 2018
    Lauren Hinkel | Oceans at MIT

    NASA/TESS

    1
    “TESS is trying to take everything that people have already done and do it better and do it across the whole sky,” says Sara Seager, the Class of 1941 Professor at MIT.
    Photo: Justin Knight.

    2
    TESS will survey the sky in a series of 13 observing segments, each 27-days long. It will spend the first year on the southern ecliptic hemisphere and the second year on the northern ecliptic hemisphere. Depending on sky position, TESS targets will be observed for a minimum of 27 days up to a maximum of 351 days. Image: Roland Vanderspek.

    Professor Sara Seager previews a new era of discovery as a leader of the TESS mission, which is expected to find some 20,000 extrasolar planets.


    A SpaceX Falcon 9 rocket lifted off on April 18 from Cape Canaveral Air Force Station carrying NASA’s Transiting Exoplanet Survey Satellite, or TESS. The MIT-led mission is the next step in the search for planets outside of the solar system and orbiting other nearby stars. The mission is designed to find exoplanets by blocking their light while the planets transition across. Video: NASA

    Ever since scientists discovered the first planet outside of our solar system, 51 Pegasi b, the astronomical field of exoplanets has exploded, thanks in large part to the Kepler Space Telescope.

    NASA/Kepler Telescope

    Now, with the successful launch of the Transiting Exoplanet Survey Satellite (TESS), Professor Sara Seager sees a revolution not only in the amount of new planetary data to analyze, but also in the potential for new avenues of scientific discovery.

    “TESS is going to essentially provide the catalog of all of the best planets for following up, for observing their atmospheres and learning more about them,” Seager says. “But it would be impossible to really describe all the different things that people are hoping to do with the data.”

    For Seager, the goal is to sift through the plethora of incoming TESS data to identify exoplanet candidates. Ultimately, she says she wants to find the best planets to follow up with atmosphere studies for signs that the planet might be suitable for life.

    “When I came to MIT 10 years ago, [MIT scientists] were starting to work on TESS, so that was the starting point,” said Seager, the Class of 1941 Professor Chair in MIT’s Department of Earth, Atmospheric and Planetary Sciences with appointments in the departments of Physics and Aeronautics and Astronautics.

    Seager is the deputy science director of TESS, an MIT-led NASA Explorer-class mission. Her credentials include pioneering exoplanet characterization, particularly of atmospheres, that form the foundation of the field. Seager is currently hunting for exoplanets with signs of life, and TESS is the next step on that path.

    So far, scientists have confirmed 3,717 exoplanets in 2,773 systems. As an all-sky survey, TESS will build on this, observing 85 percent of the cosmos containing more than 200,000 nearby stars, and researchers expect to identify some 20,000 exoplanets.

    “TESS is trying to take everything that people have already done and do it better and do it across the whole sky,” Seager says. While this mission relies on exoplanet hunting techniques developed years ago, the returns on this work should extend far into the future.

    Planet transit. NASA/Ames

    Radial Velocity Method-Las Cumbres Observatory

    Radial velocity Image via SuperWasp http http://www.superwasp.org-exoplanets.htm

    Direct imaging-This false-color composite image traces the motion of the planet Fomalhaut b, a world captured by direct imaging.

    “TESS is almost the culmination of a couple of decades of hard work, trying to iron out the wrinkles of how to find planets by the transiting method. So, TESS isn’t changing the way we look for planets, more like it’s riding on the wave of success of how we’ve done it already.”

    The TESS science leadership team have committed to delivering at least 50 exoplanets with radii less than four times that of Earth’s along with measured masses. As part of the TESS mission, an international effort to further characterize the planet candidates and their host stars down to the list of 50 with measured masses will be ongoing, using the best ground-based telescopes available.

    For the best exoplanets for follow up, Seager likens photons reaching the satellite’s cameras to money: the more photons you have, the better. Accordingly, the cameras are optimized for nearby, bright stars. Furthermore, the cameras are calibrated to favor small, red M dwarf stars, around which small planets with a rocky surface are more easily detected than around the larger, yellow sun-size stars. Additionally, researchers tuned the satellite to exoplanets with orbits of less than 13 days, so that two transits are used for discovery.

    See the full article here .

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 4:43 pm on April 25, 2018 Permalink | Reply
    Tags: , , , , , NASA TESS, Predicting the number of planets from TESS   

    From astrobites: “Predicting the number of planets from TESS” 

    Astrobites bloc

    astrobites

    Title: A Revised Exoplanet Yield from the Transiting Exoplanet Survey Satellite (TESS)
    Authors: Thomas Barclay, Joshua Pepper, Elisa V. Quintana
    First Author’s Institution: NASA Goddard Space Flight Center, University of Maryland, Baltimore, USA

    Status: Submitted to AAS Journals, open access available on arXiv

    Exoplanet hunters around the world held their breath while NASA’s Transiting Exoplanet Survey Satellite (TESS) launched last Wednesday.

    NASA/TESS

    Thankfully the launch was a success and after 60 days of orbit manoeuvring and engineering tests, TESS is expected to begin its initial two years of science observations. The question is: how many planets do we expect TESS to find?

    See the full article here .

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    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.
    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

     
  • richardmitnick 2:49 pm on April 24, 2018 Permalink | Reply
    Tags: , , , , Jacqueline Hewitt - Director - MIT Kavli Institute, , NASA TESS   

    From Kavli MIT Institute For Astrophysics and Space Research: Women in STEM -“Planets Aplenty with the TESS Mission: An Interview with the Director of the Kavli Institute for Astrophysics and Space Research 

    KavliFoundation

    http://www.kavlifoundation.org/institutes

    Kavli MIT Institute of Astrophysics and Space Research

    Kavli MIT Institute For Astrophysics and Space Research

    Adam Hadhazy, Spring 2018

    Jacqueline Hewitt discusses how the TESS exoplanet mission has already changed the institute she directs and will bring about further evolution in the years to come.

    Jacqueline Hewitt is the Director of the MIT Kavli Institute (MKI), a lead institution behind the TESS mission.(Credit: MKI)

    The Transiting Exoplanet Survey Satellite (TESS) has begun its mission to discover thousands of new exoplanets right in our cosmic background.

    NASA/TESS

    The lead organization behind TESS is the Massachusetts Institute of Technology, where members of its Kavli Institute for Astrophysics and Space Research (MKI) spearheaded the mission’s development and are serving in prominent science roles today.

    Nurturing TESS from an idea to the drawing board, and then from the fabrication lab into the final frontier has churned up a whirlwind of activity at MKI for a decade. The director of MKI, Jacqueline Hewitt, has been there for all of it. She pushed to get TESS approved by NASA, oversaw its instrument development, and will also oversee its science operations over the next two years in the hunt for Earth-like planets that could conceivably host alien life.

    For a perspective on the impact TESS has already had and will have on MKI, The Kavli Foundation spoke with Hewitt shortly after TESS’ launched on April 18, 2018. In this candid conversation, Hewitt describes the successes and challenges in making TESS a reality, as well as the excitement she and her colleagues feel serving in the vanguard of advancing our understanding of the broader universe.

    The following is an edited transcript of the discussion. The participant has been provided the opportunity to amend or edit her remarks.

    ___________________________________________________________

    THE KAVLI FOUNDATION: How did the idea for TESS first emerge at MIT?

    JACQUELINE HEWITT: It was 12 years ago and the field of exoplanets was still in its relative infancy. We did not know yet if exoplanets were these rare things or quite common in the galaxy. Astronomers were talking about the measurements we needed in order to find more planets and to study them. It’s a really difficult problem because exoplanets are, of course, so far away and so tiny and faint from a cosmic perspective.

    Back then, George Ricker, a Senior Research Scientist here at MIT and MKI, had finished up his work on the satellite HETE-2.

    MIT HETE 2 NASA

    This mission looked for sudden brightening events out in the universe, called transients, caused by the explosions of stars and other phenomena. TESS grew out of HETE-2. George and his colleagues had the realization that going to space would give them the ability to accurately gather enough light to find exoplanets when they cross their host stars, causing just a slight dimming, and also to be able to scan a big portion of the sky to find lots of these planets.

    So, I remember George walked into my office and said he had this idea for this mission. In your job as director of a place like MKI, you have to figure out how to put scarce resources into different things. A lot of people will walk into my office with ideas, and to be honest, oftentimes they’re not very good ideas. But this idea for TESS, as soon as I heard it, I thought: “Wow—this is timely, the technology is up to it, this is something we’d be able to do now.” I went into high gear at that point, trying to raise money and develop a consensus within our astronomical community that TESS would be a good thing to do.

    George had to do some technology development to make this work, to get it funded. NASA tends to avoid risk in these space missions because they’re so expensive. If you’re going to spend millions sending something in orbit, you want it to work, you know? We put quite a bit of money and time into developing a prototype camera. The whole time, George has really been the champion of TESS. He’s someone who has a real talent for designing instruments to meet a particular scientific problem.

    All the hard work paid off and NASA greenlit the mission, with George serving as the TESS Principal Investigator.

    I feel very lucky being here at MIT because we’re able to gather together the resources needed, in terms of funding and intellectual people power. The Kavli Foundation played a big and direct role, too. TESS development began shortly after we’d received our Kavli endowment, so that helped us be in a position to have resources that we could spend on things like TESS. Also, during a period when significant funding was critically needed to support research staff, the Foundation encouraged us to redirect some funds toward TESS, making sure the program stayed strong and kept moving forward.

    So, all these things have had to come together. It’s been incredible. And sort of crazy at times. [Laughter]

    _____________________________________________________
    3
    To Seek Out New Life: How the TESS Mission Will Accelerate the Hunt for Livable Alien Worlds

    The just-launched Transiting Exoplanet Survey Satellite (TESS) could soon provide the breakthrough identification of dozens of potentially habitable exoplanets right in our cosmic backyard. Two TESS scientists—Greg Berthiaume and Diana Dragomir—provide an inside look at the mission’s development and revolutionary science.

    Read the Kavli Spotlight
    _____________________________________________________

    TKF: Historically, the Institute has had a very broad astrophysics and cosmology portfolio. Could it develop more of a specialty in exoplanets in the years ahead as TESS begins delivering its bounty?

    HEWITT: I’d say in the next five years, exoplanets are definitely going to be a big part of our portfolio. Since we started doing TESS, I’ve had a number of people say to me, “Oh, MIT is the best place to be for exoplanets now.” Which we certainly weren’t 12 years ago! I’m not even sure that’s true now—there are a lot of really good places—but at least we’re in the running. We have new faculty and a lot of postdocs have shown up over the last couple of years because of TESS.

    TKF: How else has MKI evolved as a result of pursuing the TESS mission?

    HEWITT: I told you about our evolution scientifically, but another way we’ve evolved is in engineering and project management. One thing that’s very hard for a university to do is to maintain the staff needed to do space missions, or even ground-based instruments, because you need mechanical engineers and other specialized staff long term. You need to keep these people employed in between missions so you don’t have to go through the process of staffing up again. Fortunately, TESS was a nice, long sustained mission to develop. We were able to maintain some staff and they’ve been working on other projects as well as TESS. So that’s strengthened our capability moving forward.

    The TESS mission also deepened the ties between MKI and MIT’s Lincoln Laboratory, which is a federally funded research and development center that built TESS’ cameras. The engineers at Lincoln have been developing the detectors for x-ray missions for us for decades. But TESS certainly was the biggest thing we’ve ever done with Lincoln. We’ve really built a relationship between our people and those out at Lincoln, about 20 miles away, where they maintain a very deep expertise in engineering that we just cannot.

    TKF: I understand the TESS mission has physically changed MKI’s office space, too. Isn’t there now a science operations center in your building on MIT’s campus in Cambridge, Massachusetts?

    HEWITT: That’s right. We’ll actually be running the science payload—those cameras and related equipment—on TESS, and that’ll be really cool. We’ll be doing that from a sort of a war room, where we have a bunch of computer screens on the wall. We’ll be getting the data from NASA’s Deep Space Network of radio dishes worldwide, and we’ll be sending out the commands for TESS’ observing sequence.

    NASA Canberra, AU, Deep Space Network

    NASA Deep Space Network

    Now, we’re not actually running the TESS spacecraft itself, mind you; a company called Orbital ATK is doing that. They won’t let us touch the spacecraft. They don’t want a bunch of astronomers running the spacecraft! [Laughter]

    TKF: With a major mission like TESS under its belt, do you foresee MIT and MKI making additional forays into primary mission development and operation?

    HEWITT: We are having discussions about that. We are presently doing development studies on two other instruments that see the universe in x-rays. One is called Arcus, which will let us study hot gas throughout the universe that we haven’t really been able to see before. The other mission concept is called ISS-TAO, for Transient Astrophysics Observer on the International Space Station, and it will capture transients, such as gamma-ray bursts, and help us better understand them. Those transients include follow-up of the gravitational-wave events detected by the Laser Interferometer Gravitational-Wave Observatory, or LIGO, which is co-led by MIT; and one its founders Rai Weiss, is an MKI member and a Kavli Prize in Astrophysics- and Nobel Prize in Physics-winner.

    We have some ideas, too, about putting radio arrays in space or on the moon, and that’s something very challenging that I feel more confident about even trying to do now that we have the TESS experience behind us. We kind of have a feeling for what’s involved.

    TKF: TESS is the first NASA mission sent to space aboard a rocket from the commercial company SpaceX, which offers less costly rides off-Earth than legacy rockets. What is the significance of this milestone?

    HEWITT: I’m a big fan of SpaceX. I still set my alarm for three o’clock in the morning when they have a launch and I watch it on TV and then go back to bed. [Laughter]

    It was just so exciting that TESS got launched in this way, but it’s always a little scary for any spacecraft come launch time. You spend 12 years working on this remarkable machine, and then we put it on top of a column of rocket fuel. I mean, how crazy is that? [Laughter]

    This milestone really could be a gamechanger in the science we can do. With it not being so monstrously expensive to put something into space anymore, that might get us to start doing missions that are a little bit riskier and bleeding-edge in terms of technology, but which could potentially have big science rewards.

    See the full article here .

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    Mission Statement

    The mission of the MIT Kavli Institute (MKI) for Astrophysics and Space Research is to facilitate and carry out the research programs of faculty and research staff whose interests lie in the broadly defined area of astrophysics and space research. Specifically, the MKI will

    Provide an intellectual home for faculty, research staff, and students engaged in space- and ground-based astrophysics
    Develop and operate space- and ground-based instrumentation for astrophysics
    Engage in technology development
    Maintain an engineering and technical core capability for enabling and supporting innovative research
    Communicate to students, educators, and the public an understanding of and an appreciation for the goals, techniques and results of MKI’s research.

    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

     
  • richardmitnick 9:42 am on April 19, 2018 Permalink | Reply
    Tags: , , , , NASA TESS,   

    From University of New South Wales: “NASA’s new satellite a boost for UNSW starquake research” 

    U NSW bloc

    University of New South Wales

    19 Apr 2018
    Deborah Smith

    The successful launch of NASA’s planet-hunting satellite TESS will allow UNSW scientists to study the properties of nearby stars from their internal ringing sounds.

    1
    NASA’s Transiting Exoplanet Survey Satellite,TESS, will search for planets beyond our solar system. Image: NASA.

    The successful launch today of NASA’s planet-hunting satellite will allow UNSW scientists to study the properties of nearby stars from their internal ringing sounds.

    Associate Professor Dennis Stello, from the School of Physics, had a front row seat at Cape Canaveral in Florida when the SpaceX Falcon 9 rocket carrying NASA’s Transiting Exoplanet Survey Satellite, TESS, blasted off this morning at 8.51am Australian Eastern Standard Time.

    In a first-of-its-kind mission, TESS will spend about two years surveying 200,000 of the brightest stars to search for planets beyond our solar system. It will identify planets ranging from rocky Earth-sized worlds to gas giants, orbiting a wide range of stellar types and orbital distances.

    “The launch went very smoothly,” says Stello, who is part of the TESS Asteroseismic Science Consortium. “This is a very exciting time for us. TESS will be providing data on stars and planets in our cosmic backyard for many years to come.”

    TESS will be watching for phenomena called transits. A transit occurs when a planet passes in front of its star from the observer’s perspective, causing a periodic and regular dip in the star’s brightness. More than 78 percent of the approximately 3,700 confirmed exoplanets have been found using transits.

    TESS is a follow-up to the Kepler spacecraft, one of NASA’s most successful missions which found more than 2,600 exoplanets, most orbiting faint stars between 300 and 3,000 light-years from Earth using the transit method.

    TESS will focus on closer stars, between 30 and 300 light-years away, and 30 to 100 times brighter than Kepler’s targets.

    “The measurements made by TESS also allow us to detect brightness variations caused by ringing sounds inside the stars from starquakes that make the stars vibrate,” says Stello.

    By analysing the frequencies of the ringing, Stello and his team can infer the properties of the stars, such as their size, mass, and age.

    “This method, called asteroseismology, helps us understand newly discovered planet systems, and gives us a way to study detailed physics inside stars under extreme conditions we cannot reproduce here on Earth,” he says.

    See the full article here .

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    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
  • richardmitnick 9:28 am on April 19, 2018 Permalink | Reply
    Tags: , , , , , NASA TESS   

    From Kavli MIT Institute of Astrophysics and Space Research: “To Seek Out New Life: How the TESS Mission Will Accelerate the Hunt for Livable Alien Worlds’ 

    KavliFoundation

    http://www.kavlifoundation.org/institutes

    Kavli MIT Institute of Astrophysics and Space Research

    Kavli MIT Institute For Astrophysics and Space Research

    The just-launched Transiting Exoplanet Survey Satellite (TESS) could soon provide the breakthrough identification of dozens of potentially habitable exoplanets
    right in our cosmic backyard.

    NASA/TESS

    A NEW ERA IN THE SEARCH FOR EXOPLANETS—and the alien life they might host—has begun. Aboard a SpaceX rocket, the Transiting Exoplanet Survey Satellite (TESS) launched on April 18, 2018, at 6:51 PM EDT. The TESS mission, developed with support from The Kavli Foundation, is led by the Massachusetts Institute of Technology (MIT) and the MIT Kavli Institute for Astrophysics and Space Research.

    Over the next two years, TESS will scan the 200,000 or so nearest and brightest stars to Earth for telltale dimming caused when exoplanets cross their stars’ faces. Among the thousands of new worlds TESS is expected to discover should be hundreds ranging in size from about one to two times Earth. These small, mostly rocky planets will serve as prime targets for detailed follow-up observations by other telescopes in space and on the ground.

    The goal for those telescopes will be to characterize the newfound exoplanets’ atmospheres. The particular mixtures of gases in an atmosphere will reveal key clues about a world’s climate, history, and if it might even be hospitable to life.

    The Kavli Foundation spoke with two scientists on the TESS mission to get an inside look at its development and revolutionary science aim of finding the first “Earth twin” in the universe.

    The participants were:

    GREG BERTHIAUME – is the Instrument Manager for the TESS mission, in charge of ensuring the spacecraft’s cameras and other equipment will perform their science tasks. Berthiaume is based at the Massachusetts Institute of Technology’s (MIT) Lincoln Laboratory and he is also a member of the MIT Kavli Institute for Astrophysics and Space Research.

    DIANA DRAGOMIR – is an observational astronomer whose focus is on small exoplanets. Dragomir is a Hubble Postdoctoral Fellow at the MIT Kavli Institute for Astrophysics and Space Research.

    THE KAVLI FOUNDATION: Starting with the big picture, why is TESS important?

    DIANA DRAGOMIR: TESS is going to find thousands of exoplanets, which might not sound like a big deal, because we already know of nearly 4,000. But most of those discovered planets are too far away for us to do anything more than just know their size and that they are there. The difference is that TESS will be looking for planets around stars very close to us. When stars are closer to us, they’re also brighter from our point of view, and that helps us discover and study the planets around them much more easily.

    GREG BERTHIAUME: One of the things TESS is doing is helping to answer the fundamental question, “Is there other life in the universe?” People have been wondering that for thousands of years. Now TESS won’t answer that question directly, but it’s a step, just like Diana mentioned, on the path to getting us the data to see where there might be other life out there. That’s something we’ve been struggling with and questioning since we were able to come up with questions.

    TKF: What exactly do you expect TESS to find?

    DRAGOMIR: TESS will probably find 100 to 200 approximately Earth-size worlds, as well as thousands of more exoplanets all the way up to Jupiter in size.

    BERTHIAUME: We’re trying to find planets that are Earth analogs, meaning they’ll be Earth-like in their characteristics, such as size, mass, and so on. That means we want to find planets with atmospheres, with gravity similar to Earth’s. We want to find planets that are cool enough so water can be liquid on their surfaces, and not so cold that the water is frozen all the time. We call these “Goldilocks” planets, located in a star’s “habitable zone.” That’s really our target.

    DRAGOMIR: Exactly right. We want to find the first “Earth twin.” TESS will mainly find planets in the habitable zone of red dwarfs. These are stars a bit smaller and cooler than the Sun. A planet around a red dwarf can be located in an orbit closer to its star than it could be with a hotter star like our Sun and still maintain that nice, Goldilocks temperature. Closer orbits translate to more transits, or star crossings, which makes these red dwarf planets easier to find and study than planets around Sun-like stars.

    Astronomers are working hard on ways that we might push the TESS data and find some planets in the habitable zone of Sun-like stars, too. It’s challenging because those planets have longer orbital periods—years, that is—than close-in planets. That means we need a lot more observation time in order to detect enough transits of the planets across their stars to say we’ve definitely detected a planet. But we’re hopeful, so stay tuned!

    TKF: What do you need to see in order to deem any of the planets discovered by TESS as potentially habitable?

    DRAGOMIR: We want a planet to be close to Earth in size for all the reasons we just gave, but there’s a small problem with that. Those sorts of planets will probably have pretty small atmospheres, compared to how much rock makes up their bulk. And for most telescopes to be able to look at an atmosphere in detail, we actually need the planet to have a substantial atmosphere.

    This is because of a technique we use called transmission spectroscopy. It gathers the light from the star that has gone through the atmosphere of the planet when the planet is crossing the star. That light comes to us with a spectrum of the planet’s atmosphere imprinted on it, which we can analyze to identify the composition of the atmosphere. The more atmosphere there is, the more material there is that can imprint on the spectrum, giving us a bigger signal.

    If the light from the star is going through very little atmosphere, though, like we’d be looking at with an Earth twin, the signal would be very small. Based on what TESS finds, we’re therefore going to be starting with bigger planets that have a lot of atmosphere, and as we get better instruments, we’re going to move towards smaller and smaller planets with less atmosphere. It’s those latter planets which will more likely be habitable.

    BERTHIAUME: What we’re going to look for in the atmosphere are things like water vapor, oxygen, carbon dioxide—the standard gases we see in our atmosphere that life needs and life produces. We’re also going to try and measure the nasty things that aren’t compatible with life as we know it on Earth. For instance, it would be a bad thing for biology if there were too much ammonia in a world’s atmosphere. Hydrocarbons, like methane, would also be problematic in too high an abundance.

    TKF: Diana, your specialty is exoplanets smaller than Neptune—a planet four times bigger than Earth. What is our general knowledge about those kinds of worlds and how will TESS help with your research?

    DRAGOMIR: One thing we know about these planets is that they are extremely common compared to planets larger than Neptune. So that’s good. We therefore expect TESS to find lots and lots of planets smaller than Neptune for us to look at.

    Although small is bad for getting those atmospheric imprints we just talked about, if the stars are nearby and bright, we might still be able to get enough light for doing good studies. I’m hoping that we’ll get enough below Neptune-size that we’ll start looking at the atmospheres of “super-Earths,” which are planets twice the size of Earth or so. We don’t have any super-Earths in our solar system, so we’d love to get a closer look at one of these kinds of worlds. And just maybe, if we find a really, really good planetary candidate, we may be able to start looking at the atmosphere of an Earth-sized planet.

    With my research, one more thing TESS could really help with is figuring out the boundary between a very gassy planet like Neptune and a very rocky planet like Earth. We believe it’s mostly a matter of mass; have too much mass, and the planet stars to hold into a thick atmosphere. Right now, we’re not sure where that threshold is. And that matters so we know when a planet is rocky and potentially habitable, or gassy and not habitable.

    TKF: Greg, as the TESS Instrument Manager, a lot rides on your shoulders for the mission’s success. Can you tell us a bit about your job?

    BERTHIAUME: My job as instrument manager is different from a science job, for sure. My job was to make sure that all of the pieces, all the parts that go into the four flight cameras and the image processing hardware all play and work together and give us the great data that we need for Diana to go and continue to explore exoplanets. My personal role on the mission actually ends shortly after launch. Once we’ve demonstrated that the satellite provides the data that we expect, and we deal with any surprises that may come up, then I move on and data goes off to the science community.

    I definitely feel responsible for getting the quality of the data as high as it possibly can be. A lot of people worked really hard for years to build the cameras that are flying on TESS and it’s been great to be part of that team.

    TKF: New exoplanet missions like the European Space Agency’s Ariel and Plato satellites are slated to begin in the late 2020s. How might these future spacecraft complement and build on TESS’ body of work?

    DRAGOMIR: The great thing about TESS is that it’s going to give us a lot to choose from in terms of the best options for planets we’ll want to study. In that way, TESS will set the stage for Ariel’s mission, which is to deeply study the atmospheres of a select group of exoplanets.

    The Plato mission will be looking for planets that are habitable, but around bigger stars like the Sun, whereas TESS will focus on looking for habitable planets around smaller stars. I’m happy with that because I don’t want us to put all of our eggs in one basket by only looking at red dwarf stars with TESS. Planets around these red dwarfs are very exciting right now because they’re easier to study and they transit their stars more often, making them easier to find. But at the same time, red dwarfs tend to be much more active than the Sun. When a star is active, that means it often expels bursts of radiation called flares. These flares could be very damaging to a planet’s atmosphere and make the world uninhabitable.

    In the end, we of course live around a Sun-like star, and so far, we are the only “we” we know of in the universe. So for those reasons, it’s great to have Plato complementarily come along and find those planets around suns that TESS will probably not be able to find.

    TKF: When do you expect TESS’ first discoveries of brand new worlds to be reported?

    BERTHIAUME: First, it’s going to take a while to get TESS into its unique orbit. It’s the first time we’re putting a spacecraft in a new kind of far-ranging, highly elliptical orbit, where the gravity from the Earth and the Moon will keep TESS very stable, both from an orbit perspective and from a thermal perspective. So a big part of what’s going to happen over the first six weeks is just achieving that final orbit.

    Then there’s a period of time where there’ll be data collected to make sure the instruments are working as expected, as well as getting our data processing pipeline tuned up. I think we’ll start to see interesting results come out sometime this summer.

    TKF: Besides new worlds, what else might TESS reveal about the universe?

    2
    A set of flight camera electronics on one of the TESS cameras, developed by the MIT Kavli Institute for Astrophysics and Space Research (MKI). (Image: MIT Kavli Institute)

    DRAGOMIR: Because TESS is observing so much of the sky, it’s going to see lots of things that are happening in real-time, not just exoplanets crossing stars. As for those stars, we can learn a lot about their properties and even measure their masses quite precisely by doing asteroseismology with TESS. This technique involves tracking brightness changes as sound waves move through the interiors of stars—just like how seismic waves pass through the Earth’s rock and molten insides during earthquakes.

    We’ll also be studying the flaring activity of the stars, which as we spoke about earlier might make close-in, temperate planets around red dwarf stars uninhabitable.

    Moving up in size, scientists will want to search the TESS data for evidence of small black holes. These extreme objects, formed when colossal stars explode, can orbit normal stars that are still “alive,” so to speak. These systems will help us better understand how those black holes form and how they interact with companion stars.

    And then finally, going even bigger, TESS will look at galaxies called quasars. These ultra-bright galaxies are powered by supermassive black holes in their cores. TESS will help us monitor how quasars’ brightness changes, which we can link back to the dynamics of their black holes.

    TKF: The James Webb Space Telescope, hailed as the successor to the Hubble Space Telescope, has long been talked about as a primary instrument for doing the detailed follow-up observations on promising exoplanets found by TESS. However, James Webb’s launch, already delayed multiple times, just got pushed out yet another year, to 2020. How will the ongoing James Webb delays affect the TESS mission?

    DRAGOMIR: The James Webb delay is not so much of a problem because it actually gives us more time to collect great target planets with TESS. Before we can use James Webb to really observe candidate exoplanets and study their atmospheres, we first need to confirm the planets are real—that what we think are planets are not false positives caused, for instance, by stellar activity. That confirmation process takes weeks, using support observations from ground-based telescopes. It will then also take weeks to months to obtain the mass of the planets. We measure that by registering how much planets cause their host stars to experience slight “wobbles” in their motion over time, owing to the planets’ gravities, which are determined by their mass.

    Once you have that mass, plus the size of an exoplanet based on how much starlight it blocks during a TESS detection, you can measure its density and determine if it’s rocky or gaseous. With this information, it is then easier to decide which planets we want to prioritize, and the more we can make sense out of what James Webb will tell us about their atmospheres.

    TKF: Spacecraft sometimes have humorous or even profound extra elements built into them. One example: the “Golden Records” on the twin Voyager spacecraft, which contain images and sounds of life and civilization on Earth, including the Taj Mahal and birdsong. Are there any such items included on TESS? Any subtle maker’s marks or messages?

    BERTHIAUME: One of the things that’s flying along with TESS is a metal plaque that has the signatures of many of the people who worked on developing and building the spacecraft. That was an exciting thing for us.

    DRAGOMIR: That’s cool. I didn’t know that!

    BERTHIAUME: Also, NASA ran an international contest inviting people from around the world to submit drawings of what they thought exoplanets might look like. I know many children participated. All of those drawings were scanned onto a thumb drive and they’re flying along with TESS. The spacecraft’s orbit is stable for a century at least, so the plaque and the drawings will be in space for a long time!

    See the full article here .

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    The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

    The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.

    Mission Statement

    The mission of the MIT Kavli Institute (MKI) for Astrophysics and Space Research is to facilitate and carry out the research programs of faculty and research staff whose interests lie in the broadly defined area of astrophysics and space research. Specifically, the MKI will

    Provide an intellectual home for faculty, research staff, and students engaged in space- and ground-based astrophysics
    Develop and operate space- and ground-based instrumentation for astrophysics
    Engage in technology development
    Maintain an engineering and technical core capability for enabling and supporting innovative research
    Communicate to students, educators, and the public an understanding of and an appreciation for the goals, techniques and results of MKI’s research.

     
  • richardmitnick 8:52 am on April 18, 2018 Permalink | Reply
    Tags: , , , , NASA TESS,   

    From Vanderbilt University: “NASA’s TESS mission to discover new worlds will use a map developed at Vanderbilt” 

    Vanderbilt U Bloc

    Vanderbilt University

    1
    TESS. NASA.

    Apr. 16, 2018
    No writer credit

    When NASA’s Transiting Exoplanet Survey Satellite (TESS) launches from Florida’s Cape Canaveral on a mission to identify potentially habitable planets orbiting nearby stars, it will carry with it a map, of sorts, developed right here at Vanderbilt. Keivan Stassun, Stevenson Professor of Physics and Astronomy, serves as a deputy principal investigator on the mission, tasked with identifying the most promising stars for TESS to target.

    “The TESS mission represents a dream come true for me and for the many scientists and engineers who have worked on the mission,” said Stassun. “Our ambition is to not only detect hundreds of Earth-like worlds in other solar systems, but to find them around our closest neighboring solar systems.”

    TESS is looking for small, rocky, Earth-like planets, which are most likely to be found orbiting red dwarfs like Barnard’s Star, named after the Vanderbilt astronomer who first discovered it. Using data from a number of sources, including Vanderbilt’s KELT telescope and the star “flicker” analysis method pioneered at Vanderbilt, Stassun and his team have been working since 2012 to narrow down the field from 470 million stars visible to TESS to the 250,000 most likely to host a planet like our own.

    KELT South robotic telescope, Southerland, South Africa, jointly operated by Ohio State, Vanderbilt and Lehigh universities

    The work to sift through such a massive volume of data was done by Vanderbilt undergraduates, graduate students and postdoctoral scientists associated with the Vanderbilt Initiative in Data-intensive Astrophysics (VIDA), as well as students, developers, and data visualizers associated with the Vanderbilt Initiative for Autism & Innovation.

    Focusing on the nearest stars means that any new worlds that TESS discovers will be close enough that future telescopes like the James Webb Space Telescope will be able to detect and measure the thin atmospheres of those planets, said Stassun.

    “In a few years’ time, we may very well know that there are other habitable planets out there, with breathable atmospheres,” he said. “Of course, we won’t yet know whether there is anything, or anyone, there breathing it. Still, this is a remarkable time in human history and a huge leap for our understanding of our place in the universe.”

    See the full article here .

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    Commodore Cornelius Vanderbilt was in his 79th year when he decided to make the gift that founded Vanderbilt University in the spring of 1873.

    The $1 million that he gave to endow and build the university was the commodore’s only major philanthropy. Methodist Bishop Holland N. McTyeire of Nashville, husband of Amelia Townsend who was a cousin of the commodore’s young second wife Frank Crawford, went to New York for medical treatment early in 1873 and spent time recovering in the Vanderbilt mansion. He won the commodore’s admiration and support for the project of building a university in the South that would “contribute to strengthening the ties which should exist between all sections of our common country.”

    McTyeire chose the site for the campus, supervised the construction of buildings and personally planted many of the trees that today make Vanderbilt a national arboretum. At the outset, the university consisted of one Main Building (now Kirkland Hall), an astronomical observatory and houses for professors. Landon C. Garland was Vanderbilt’s first chancellor, serving from 1875 to 1893. He advised McTyeire in selecting the faculty, arranged the curriculum and set the policies of the university.

    For the first 40 years of its existence, Vanderbilt was under the auspices of the Methodist Episcopal Church, South. The Vanderbilt Board of Trust severed its ties with the church in June 1914 as a result of a dispute with the bishops over who would appoint university trustees.

    kirkland hallFrom the outset, Vanderbilt met two definitions of a university: It offered work in the liberal arts and sciences beyond the baccalaureate degree and it embraced several professional schools in addition to its college. James H. Kirkland, the longest serving chancellor in university history (1893-1937), followed Chancellor Garland. He guided Vanderbilt to rebuild after a fire in 1905 that consumed the main building, which was renamed in Kirkland’s honor, and all its contents. He also navigated the university through the separation from the Methodist Church. Notable advances in graduate studies were made under the third chancellor, Oliver Cromwell Carmichael (1937-46). He also created the Joint University Library, brought about by a coalition of Vanderbilt, Peabody College and Scarritt College.

    Remarkable continuity has characterized the government of Vanderbilt. The original charter, issued in 1872, was amended in 1873 to make the legal name of the corporation “The Vanderbilt University.” The charter has not been altered since.

    The university is self-governing under a Board of Trust that, since the beginning, has elected its own members and officers. The university’s general government is vested in the Board of Trust. The immediate government of the university is committed to the chancellor, who is elected by the Board of Trust.

    The original Vanderbilt campus consisted of 75 acres. By 1960, the campus had spread to about 260 acres of land. When George Peabody College for Teachers merged with Vanderbilt in 1979, about 53 acres were added.

    wyatt centerVanderbilt’s student enrollment tended to double itself each 25 years during the first century of the university’s history: 307 in the fall of 1875; 754 in 1900; 1,377 in 1925; 3,529 in 1950; 7,034 in 1975. In the fall of 1999 the enrollment was 10,127.

    In the planning of Vanderbilt, the assumption seemed to be that it would be an all-male institution. Yet the board never enacted rules prohibiting women. At least one woman attended Vanderbilt classes every year from 1875 on. Most came to classes by courtesy of professors or as special or irregular (non-degree) students. From 1892 to 1901 women at Vanderbilt gained full legal equality except in one respect — access to dorms. In 1894 the faculty and board allowed women to compete for academic prizes. By 1897, four or five women entered with each freshman class. By 1913 the student body contained 78 women, or just more than 20 percent of the academic enrollment.

    National recognition of the university’s status came in 1949 with election of Vanderbilt to membership in the select Association of American Universities. In the 1950s Vanderbilt began to outgrow its provincial roots and to measure its achievements by national standards under the leadership of Chancellor Harvie Branscomb. By its 90th anniversary in 1963, Vanderbilt for the first time ranked in the top 20 private universities in the United States.

    Vanderbilt continued to excel in research, and the number of university buildings more than doubled under the leadership of Chancellors Alexander Heard (1963-1982) and Joe B. Wyatt (1982-2000), only the fifth and sixth chancellors in Vanderbilt’s long and distinguished history. Heard added three schools (Blair, the Owen Graduate School of Management and Peabody College) to the seven already existing and constructed three dozen buildings. During Wyatt’s tenure, Vanderbilt acquired or built one-third of the campus buildings and made great strides in diversity, volunteerism and technology.

    The university grew and changed significantly under its seventh chancellor, Gordon Gee, who served from 2000 to 2007. Vanderbilt led the country in the rate of growth for academic research funding, which increased to more than $450 million and became one of the most selective undergraduate institutions in the country.

    On March 1, 2008, Nicholas S. Zeppos was named Vanderbilt’s eighth chancellor after serving as interim chancellor beginning Aug. 1, 2007. Prior to that, he spent 2002-2008 as Vanderbilt’s provost, overseeing undergraduate, graduate and professional education programs as well as development, alumni relations and research efforts in liberal arts and sciences, engineering, music, education, business, law and divinity. He first came to Vanderbilt in 1987 as an assistant professor in the law school. In his first five years, Zeppos led the university through the most challenging economic times since the Great Depression, while continuing to attract the best students and faculty from across the country and around the world. Vanderbilt got through the economic crisis notably less scathed than many of its peers and began and remained committed to its much-praised enhanced financial aid policy for all undergraduates during the same timespan. The Martha Rivers Ingram Commons for first-year students opened in 2008 and College Halls, the next phase in the residential education system at Vanderbilt, is on track to open in the fall of 2014. During Zeppos’ first five years, Vanderbilt has drawn robust support from federal funding agencies, and the Medical Center entered into agreements with regional hospitals and health care systems in middle and east Tennessee that will bring Vanderbilt care to patients across the state.

    studentsToday, Vanderbilt University is a private research university of about 6,500 undergraduates and 5,300 graduate and professional students. The university comprises 10 schools, a public policy center and The Freedom Forum First Amendment Center. Vanderbilt offers undergraduate programs in the liberal arts and sciences, engineering, music, education and human development as well as a full range of graduate and professional degrees. The university is consistently ranked as one of the nation’s top 20 universities by publications such as U.S. News & World Report, with several programs and disciplines ranking in the top 10.

    Cutting-edge research and liberal arts, combined with strong ties to a distinguished medical center, creates an invigorating atmosphere where students tailor their education to meet their goals and researchers collaborate to solve complex questions affecting our health, culture and society.

    Vanderbilt, an independent, privately supported university, and the separate, non-profit Vanderbilt University Medical Center share a respected name and enjoy close collaboration through education and research. Together, the number of people employed by these two organizations exceeds that of the largest private employer in the Middle Tennessee region.
    Related links

     
  • richardmitnick 7:49 am on April 17, 2018 Permalink | Reply
    Tags: , , , , , From NASA Spaceflight: TESS, NASA TESS   

    From NASA Spaceflight: TESS 

    NASA Spaceflight

    NASA Spaceflight

    April 16, 2018
    Chris Gebhardt

    TESS background/overview:

    NASA/TESS

    The original idea for TESS goes back to 2005 when Dr. George Ricker was the Principle Investigator High Energy Transient Explorer (HETE) – the first satellite mission dedicated to the study of gamma-ray bursts. Slowly, the idea evolved in 2008 and 2009, with Dr. Ricker, now TESS’s Principal Investigator at MIT (Massachusetts Institute of Technology), saying “We wanted to initially try to do this as a privately funded system, and MIT was very helpful for us. We had support from Google for some of the studies that were originally going to be done.”

    That led to a collaboration with NASA Ames to create a proposal for a small-class explorer exoplanet mission that was ultimately not selected for flight. That then led to a partnership with Orbital ATK and the Goddard Space Flight Center in Greenbelt, Maryland, for a revised mission proposal over 2011 and 2012.

    TESS was officially selected for inclusion in NASA’s Medium Explorer mission program on 5 April 2013, and with just over five years of design and build operations, now stands ready to launch. “It’s been a long time coming. It’s been 13 years, but for the last five years, basically, pretty much [everything with the mission has been] the same,” said Dr. Ricker.

    1
    TESS undergoes final pre-launch processing at the Kennedy Space Flight Center. Credit: Chris Gebhart for NSF/L2

    While TESS is generally perceived as a follow-on to NASA’s Kepler planet hunting satellite, it will perform a very different kind of mission. Where Kepler was a prolonged, deep, and narrow field observatory that looked continuously at specific stars in one quarter of 1% of the sky at an optimal range of 2,000 to 3,000 light years distance, TESS will perform a wide- and shallow-field survey covering 85% of the sky with an optimal distance stretching to 300 light years.

    TESS will accomplish its observations by using the sole science instrument onboard: a package of four wide-field-of-view CCD cameras with a low-noise, low-power 16.8 megapixel CCD detector. Each camera as a 24° x 24° field of view, a 100 mm (4 in) pupil diameter, a lens assembly with seven optical elements, and a bandpass range of 600 to 1,000 nm.

    When functioning together – as designed – the four cameras have a 24° x 96° field of view.

    The overall spacecraft is built on a LEOStar-2 satellite bus by Orbital ATK. The spacecraft bus is capable of three-axis stabilization via four hydrazine thrusters as well as four reaction wheels. This provides TESS’s cameras with greater than three-arc-second fine pointing control – necessary for the sensitive light observations TESS will perform once in its science orbit.

    The data collected during TESS’s observational campaigns – as well as general spacecraft communications – will route through a Ka-band antenna with a 100 Mbit/s downlink capability. The entire craft is powered by two solar arrays capable of generating 400 watts.

    “There’s more than 100 scientists and other personnel cooperating on the mission,” said Dr. Ricker, “and as far as the mission itself is concerned, all the work that was involved in designing, developing, and building the hardware, we’ve estimated that there’s more than a million person-hours that have gone into that over the past five years.”

    Launch and Orbit:

    The launch phase of the mission will see a Falcon 9 deliver TESS into a lunar transfer orbit, sending the craft to a precise point when the moon’s gravity will grab TESS and fling it out into a farther orbit than it’s initially launched into.

    At 350 kg (772 lb), TESS is the lightest-known payload to have ever launched on a Falcon 9. After lifting off from SLC-40 at the Cape Canaveral Air Force Station, FL, the Falcon 9 will fly due east from the pad. The first stage, after 2 minutes 29 seconds of powered flight, will separate from the second stage and perform a landing on the Of Course I Still Love You drone ship in the Atlantic.

    SpaceX will also attempt to recover the payload fairing, but as there is no fairing catching boat – yet – on the east coast, the fairing will parachute into the ocean for intact recovery, serving primarily as a test of the new recovery systems.

    For the launch, after stage separation, the second stage will continue to fire its single MVac (vacuum optimized Merlin engine) until SECO-1 (Stage Engine Cut Off -1) at 8minutes 22 seconds into flight. This will be followed by a 32 minute 33 second coast of the stage and TESS before the second stage engine re-starts for a burn to send TESS into a Lunar Transfer Orbit.

    Shortly after SECO-2, TESS will separate from the top of the Falcon 9 second stage at 48 minutes 42 seconds after launch having been placed into a super synchronous transfer orbit of 200 x 270,000 km (124 x 167,770 mi). The second stage will then perform a third burn to inject itself into a disposal hyperbolic (Earth-escape) orbit.

    Over the first five days, TESS’s control teams will check out the overall health of the spacecraft before activating TESS’s science instruments 7-8 days after launch. TESS will then perform a final lunar flyby on 16 May – one month after launch, a lunar gravity assist which will change the the craft’s orbital inclination to send it into its 13.7 day, 108,000 x 373,000 km (67,000 x 232,000 mi) science orbit of Earth – an orbit that is in perfect 2:1 resonance with the moon.

    2
    The maneuvers and encounters Leading to the final TESS orbit. PLEA and PLEP are the post lunar-encounter-apogee and perigee, respectively. Credit Ricker et al. 2015.

    The specific orbit, referred to as the P/2 lunar resonant orbit, will place TESS completely outside the Van Allen Radiation belts, with TESS’s apogee (farthest point in orbit from the Earth) approximately 90 degrees away from the position of the Moon. This will minimize the Moon’s potential destabilizing effect on TESS and maintain a stable orbit for decades while also providing a consistent, good camera temperature range for the observatory’s operations.

    Moreover, this orbit will provide TESS with unobstructed views of both the Northern and Southern Hemispheres. For almost all of its orbit, TESS will be in data gathering mode, only transmitting its stored data to Earth once per orbit during the three hours of its closest approach to Earth, or perigee. Assuming an on-time launch, TESS will enter operations on 12 June.

    Overall, TESS has daily launch opportunities from 16-21 April, no launch opportunity on the 22nd (per NASA documentation), and then daily opportunities again from 23-26 April. There is no opportunity on 22 April because the amount of time between the consecutive daily opportunities on 21 and 23 April is just slightly longer than 24 hours, thus barely skipping over all times on the 22nd.

    However, if for some reason TESS is not off the ground by 26 April, the exoplanet hunter must stand down launch operations so that NASA’s Launch Services Provider (LSP) group can shift gears to support the agency’s InSight mission launch to Mars from Vandenberg Air Force Base, California.

    The LSP does not have a large enough staff to support two missions from both coasts, and since InSight has a short interplanetary launch window it must launch within, InSight would get priority over TESS. After InSight, TESS has additional launch opportunities in both May and June.

    Mission:

    Once its checkout phase is complete, TESS will begin its 26 observational campaigns (13 for each hemisphere) to survey 85% of the sky for transiting exoplanets near Earth. Observations will start with the Southern Hemisphere, and those 13 campaigns will last approximately one year.

    According to Dr. Ricker, choosing to survey the Southern Hemisphere first was “a function of the follow-up resources that are currently available. Many of the most powerful telescopes that ground-based astronomers use are located in the Southern Hemisphere.”

    TESS will then be re-aimed to perform the 13 observational campaigns needed to cover the Northern Hemisphere. During all 26 campaigns, the entire south and north polar sky regions will receive near-continuous year-long assessments from TESS’s cameras – as each observation campaign for the Southern and Northern Hemispheres overlap completely at their respective pole.

    3
    Dr. Ricker shows the number of exoplanets TESS is predicted to find within 100 parsecs (326 lightyears) of Earth. Credit Ricker et al. for NSF/L2

    Every 13.7 days, when TESS swings closest to Earth, the craft will downlink its observation data to scientists at MIT who will process it and make it available to other scientists and the public. Specifically, TESS’s team will focus on the 1,000 closest red dwarf stars to Earth as well as nearby G, K, and M type stars with apparent magnitudes greater than 12.

    Over its primary 2 year mission, TESS will observe about half a million stars in an area 400 times larger than the Kepler mission and is expected to find 20,000 exoplanets – including 500-1,000 Earth-sized planets and Super-Earths.

    These planets will be added to the growing number of known exoplanets. According to NASA’s Exoplanet Archive hosted by CalTech, as of 12 April 2018, there are 3,717 known exoplanets with 2,652 of those found by the Kepler Space Telescope.

    TESS’s primary mission duration is two years, during which all of its science objectives are scheduled to be completed. While a mission extension is never a guarantee, TESS can be extended for additional observations based on its design and orbit. “We can extend, because the orbit will be operating and aligned for more than two decades,” said Dr. Ricker. “Now, as is the case for many Explorer missions, we fully expect that there will be an extended mission for TESS, so we pre-designed the satellite and the operation so that it can go on for a much longer time.”

    See the full article here .

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    NASASpaceFlight.com, now in its eighth year of operations, is already the leading online news resource for everyone interested in space flight specific news, supplying our readership with the latest news, around the clock, with editors covering all the leading space faring nations.

    Breaking more exclusive space flight related news stories than any other site in its field, NASASpaceFlight.com is dedicated to expanding the public’s awareness and respect for the space flight industry, which in turn is reflected in the many thousands of space industry visitors to the site, ranging from NASA to Lockheed Martin, Boeing, United Space Alliance and commercial space flight arena.

    With a monthly readership of 500,000 visitors and growing, the site’s expansion has already seen articles being referenced and linked by major news networks such as MSNBC, CBS, The New York Times, Popular Science, but to name a few.

     
  • richardmitnick 11:15 am on April 13, 2018 Permalink | Reply
    Tags: , MIT led NASA High Energy Transient Explorer 2HETE 2 NASA, NASA TESS   

    From MIT: “TESS readies for takeoff” 

    MIT News

    MIT Widget

    MIT News

    April 12, 2018
    Jennifer Chu

    1
    A set of flight camera electronics on one of the TESS cameras, developed by the MIT Kavli Institute for Astrophysics and Space Research (MKI), will transmit exoplanet data from the camera to a computer aboard the spacecraft that will process it before transmitting it back to scientists on Earth. Image: MIT Kavli Institute.

    2
    NASA’s Transiting Exoplanet Survey Satellite (TESS), shown here in a conceptual illustration, will identify exoplanets orbiting the brightest stars just outside our solar system. TESS will search for exoplanets orbiting stars within hundreds of light-years of our solar system. Looking at these close, bright stars will allow large ground-based telescopes and the James Webb Space Telescope to do follow-up observations on the exoplanets TESS finds to characterize their atmospheres. Image: NASA’s Goddard Space Flight Center.

    3
    NASA’s Transiting Exoplanet Survey Satellite (TESS), shown here in a conceptual illustration, will identify exoplanets orbiting the brightest stars just outside our solar system. Image: NASA’s Goddard Space Flight Center.

    Satellite developed by MIT aims to discover thousands of nearby exoplanets, including at least 50 Earth-sized ones.

    There are potentially thousands of planets that lie just outside our solar system — galactic neighbors that could be rocky worlds or more tenuous collections of gas and dust. Where are these closest exoplanets located? And which of them might we be able to probe for clues to their composition and even habitability? The Transiting Exoplanet Survey Satellite (TESS) will be the first to seek out these nearby worlds.

    The NASA-funded spacecraft, not much larger than a refrigerator, carries four cameras that were conceived, designed, and built at MIT, with one wide-eyed vision: to survey the nearest, brightest stars in the sky for signs of passing planets.

    Now, more than a decade since MIT scientists first proposed the mission, TESS is about to get off the ground. The spacecraft is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station in Florida, no earlier than April 16, at 6:32 p.m. EDT.

    4
    The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever space borne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. (NASA’s Goddard Space Flight Center/CI Lab).

    TESS will spend two years scanning nearly the entire sky — a field of view that can encompass more than 20 million stars. Scientists expect that thousands of these stars will host transiting planets, which they hope to detect through images taken with TESS’s cameras.

    Amid this extrasolar bounty, the TESS science team at MIT aims to measure the masses of at least 50 small planets whose radii are less than four times that of Earth. Many of TESS’s planets should be close enough to our own that, once they are identified by TESS, scientists can zoom in on them using other telescopes, to detect atmospheres, characterize atmospheric conditions, and even look for signs of habitability.

    “TESS is kind of like a scout,” says Natalia Guerrero, deputy manager of TESS Objects of Interest, an MIT-led effort that will catalog objects captured in TESS data that may be potential exoplanets.

    “We’re on this scenic tour of the whole sky, and in some ways we have no idea what we will see,” Guerrero says. “It’s like we’re making a treasure map: Here are all these cool things. Now, go after them.”

    A seed, planted in space

    TESS’s origins arose from an even smaller satellite that was designed and built by MIT and launched into space by NASA on Oct. 9, 2000. The High Energy Transient Explorer 2, or HETE-2, orbited Earth for seven years, on a mission to detect and localize gamma-ray bursts — high-energy explosions that emit massive, fleeting bursts of gamma and X-rays.

    MIT led NASA High Energy Transient Explorer 2HETE 2 NASA

    To detect such extreme, short-lived phenomena, scientists at MIT, led by principal investigator George Ricker, integrated into the satellite a suite of optical and X-ray cameras outfitted with CCDs, or charge-coupled devices, designed to record intensities and positions of light in an electronic format.

    “With the advent of CCDs in the 1970s, you had this fantastic device … which made a lot of things easier for astronomers,” says HETE-2 team member Joel Villasenor, who is now also instrument scientist for TESS. “You just sum up all the pixels on a CCD, which gives you the intensity, or magnitude, of light. So CCDs really broke things open for astronomy.”

    In 2004, Ricker and the HETE-2 team wondered whether the satellite’s optical cameras could pick out other objects in the sky that had begun to attract the astronomy community: exoplanets. Around this time, fewer than 200 planets outside our solar system had been discovered. A few of these were found with a technique known as the transit method, which involves looking for periodic dips in the light from certain stars, which may signal a planet passing in front of the star.

    “We were thinking, was the photometry of HETE-2’s cameras sufficient so that we could point to a part of the sky and detect one of these dips? Needless to say, it didn’t exactly work,” Villasenor recalls. “But that was sort of the seed that started us thinking, maybe we should try to fly CCDs with a camera to try and detect these things.”

    A path, cleared

    In 2006, Ricker and his team at MIT proposed a small, low cost satellite (HETE-S) to NASA as a Discovery class mission, and later on as a privately funded mission for $20 million. But as the cost of, and interest in, an all-sky exoplanet survey grew, they decided instead to seek NASA funding, at a higher level of $120 million. In 2008, they submitted a proposal for a NASA Small Explorer (SMEX) Class Mission with the new name — TESS.

    At this time, the satellite design included six CCD cameras, and the team proposed that the spacecraft fly in a low-Earth orbit, similar to that of HETE-2. Such an orbit, they reasoned, should keep observing efficiency relatively high, as they already had erected data-receiving ground stations for HETE-2 that could also be put to use for TESS.

    But they soon realized that a low-Earth orbit would have a negative impact on TESS’s much more sensitive cameras. The spacecraft’s reaction to the Earth’s magnetic field, for example, could lead to significant “spacecraft jitter,” producing noise that hides an exoplanet’s telltale dip in starlight.

    NASA bypassed this first proposal, and the team went back to the drawing board, this time emerging with a new plan that hinged on a completely novel orbit. With the help of engineers from Orbital ATK, the Aerospace Corporation, and NASA’s Goddard Space Flight Center, the team identified a never-before-used “lunar-resonant” orbit that would keep the spacecraft extremely stable, while giving it a full-sky view.

    Once TESS reaches this orbit, it will slingshot between the Earth and the moon on a highly elliptical path that could keep TESS orbiting for decades, shepherded by the moon’s gravitational pull.

    “The moon and the satellite are in a sort of dance,” Villasenor says. “The moon pulls the satellite on one side, and by the time TESS completes one orbit, the moon is on the other side tugging in the opposite direction. The overall effect is the moon’s pull is evened out, and it’s a very stable configuration over many years. Nobody’s done this before, and I suspect other programs will try to use this orbit later on.”

    In its current planned trajectory, TESS will swing out toward the moon for less than two weeks, gathering data, then swing back toward the Earth where, on its closest approach, it will transmit the data back to ground stations from 67,000 miles above the surface before swinging back out. Ultimately, this orbit will save TESS a huge amount of fuel, as it won’t need to burn its thrusters on a regular basis to keep on its path.

    With this revamped orbit, the TESS team submitted a second proposal in 2010, this time as an Explorer class mission, which NASA approved in 2013. It was around this time that the Kepler Space Telescope ended its original survey for exoplanets. The observatory, which was launched in 2009, stared at one specific patch of the sky for four years, to monitor the light from distant stars for signs of transiting planets.

    By 2013, two of Kepler’s four reaction wheels had worn out, preventing the spacecraft from continuing its original survey. At this point, the telescope’s measurements had enabled the discovery of nearly 1,000 confirmed exoplanets. Kepler, designed to study far-off stars, paved the way for TESS, a mission with a much wider view, to scan the nearest stars to Earth.

    “Kepler went up, and was this huge success, and researchers said, ‘We can do this kind of science, and there are planets everywhere,” says TESS member Jennifer Burt, an MIT-Kavli postdoc. “And I think that was really the scientific check box that we needed for NASA to say, ‘Okay, TESS makes a lot of sense now.’ It’ll enable not just detecting planets, but finding planets that we can thoroughly characterize after the fact.”

    Stripes in the sky

    With the selection by NASA, the TESS team set up facilities on campus and in MIT’s Lincoln Laboratory to build and test the spacecraft’s cameras. The engineers designed “deep depletion” CCDs specifically for TESS, meaning that the cameras can detect light over a wide range of wavelengths up to the near infrared. This is important, as many of the nearby stars TESS will monitor are red-dwarfs — small, cool stars that emit less brightly than the sun and in the infrared part of the electromagnetic spectrum.

    If scientists can detect periodic dips in the light from such stars, this may signal the presence of planets with significantly tighter orbits than that of Earth. Nevertheless, there is a chance that some of these planets may be within the “habitable zone,” as they would circle much cooler stars, compared with the sun. Since these stars are relatively close by, scientists can do follow-up observations with ground-based telescopes to help identify whether conditions might indeed be suitable for life.

    TESS’s cameras are mounted on the top of the satellite and surrounded by a protective cone to shield them from other forms of electromagnetic radiation. Each camera has a 24 by 24 degree view of the sky, large enough to encompass the Orion constellation. The satellite will start its observations in the Southern Hemisphere and will divide the sky into 13 stripes, monitoring each segment for 27 days before pivoting to the next. TESS should be able to observe nearly the entire sky in the Southern Hemisphere in its first year, before moving on to the Northern Hemisphere in its second year.

    While TESS points at one stripe of the sky, its cameras will take pictures of the stars in that portion. Ricker and his colleagues have made a list of 200,000 nearby, bright stars that they would particularly want to observe. The satellite’s cameras will create “postage stamp” images that include pixels around each of these stars. These images will be taken every two minutes, in order to maximize the chance of catching the moment that a planet crosses in front of its star. The cameras will also take full-frame images of all the stars in a particular stripe of the sky, every 30 minutes.

    “With the two-minute pictures, you can get a movie-like image of what the starlight is doing as the planet is crossing in front of its host star,” Guerrero says. “For the 30-minute images, people are excited about maybe seeing supernovae, asteroids, or counterparts to gravitational waves. We have no idea what we’re going to see at that timescale.”

    Are we alone?

    After TESS launches, the team expects that the satellite will reestablish contact within the first week, during which it will turn on all its instruments and cameras. Then, there will be a 60-day commissioning phase, as engineers and scientists at Orbital ATK, NASA, and MIT calibrate the instruments and monitor the satellite’s trajectory and performance. After that, TESS will begin to collect and downlink images of the sky. Scientists at MIT and NASA will take the raw data and convert it into light curves that indicate the changing brightness of a star over time.

    From there, the TESS Science Team, including Sara Seager, the Class of 1941 Professor of Earth, Atmospheric and Planetary Sciences, and deputy director of science for TESS, will look through thousands of light curves, for at least two similar dips in starlight, indicating that a planet may have passed twice in front of its star. Seager and her colleagues will then employ a battery of methods to determine the mass of a potential planet.

    “Mass is a defining planetary characteristic,” Seager says. “If you just know that a planet is twice the size of Earth, it could be a lot of things: a rocky world with a thin atmosphere, or what we call a “mini-Neptune” — a rocky world with a giant gas envelope, where it would be a huge greenhouse blanket, and there would be no life on the surface. So mass and size together give us an average planet density, which tells us a huge amount about what the planet is.”

    During TESS’s two-year mission, Seager and her colleagues aim to measure the masses of 50 planets with radii less than four times that of Earth — dimensions that could signal further observations for signs of habitability. Meanwhile, the whole scientific community and public will get a chance to search through TESS data for their own exoplanets. Once the data are calibrated, the team will make them publicly available. Anyone will be able to download the data and draw their own interpretations, including high school students, armchair astronomers, and other research institutions.

    With so many eyes on TESS’S data, Seager says there’s a chance that, some day, a nearby planet discovered by TESS might be found to have signs of life.

    “There’s no science that will tell us life is out there right now, except that small rocky planets appear to be incredibly common,” Seager says. “They appear to be everywhere we look. So it’s got to be there somewhere.”

    TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. George Ricker of MIT’s Kavli Institute for Astrophysics and Space Research serves as principal investigator for the mission. Additional partners include Orbital ATK, NASA’s Ames Research Center, the Harvard-Smithsonian Center for Astrophysics, and the Space Telescope Science Institute. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.

    See the full article here .

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