11 research outputs found

    EarthFinder Probe Mission Concept Study: Characterizing nearby stellar exoplanet systems with Earth-mass analogs for future direct imaging

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    EarthFinder is a NASA Astrophysics Probe mission concept selected for study as input to the 2020 Astrophysics National Academies Decadal Survey. The EarthFinder concept is based on a dramatic shift in our understanding of how PRV measurements should be made. We propose a new paradigm which brings the high precision, high cadence domain of transit photometry as demonstrated by Kepler and TESS to the challenges of PRV measurements at the cm/s level. This new paradigm takes advantage of: 1) broad wavelength coverage from the UV to NIR which is only possible from space to minimize the effects of stellar activity; 2) extremely compact, highly stable, highly efficient spectrometers (R>150,000) which require the diffraction-limited imaging possible only from space over a broad wavelength range; 3) the revolution in laser-based wavelength standards to ensure cm/s precision over many years; 4) a high cadence observing program which minimizes sampling-induced period aliases; 5) exploiting the absolute flux stability from space for continuum normalization for unprecedented line-by-line analysis not possible from the ground; and 6) focusing on the bright stars which will be the targets of future imaging missions so that EarthFinder can use a ~1.5 m telescope.Comment: NASA Probe Mission concept white paper for 2020 Astrophysics National Academies Decadal Surve

    EarthFinder Probe Mission Concept Study: Characterizing nearby stellar exoplanet systems with Earth-mass analogs for future direct imaging

    Get PDF
    EarthFinder is a NASA Astrophysics Probe mission concept selected for study as input to the 2020 Astrophysics National Academies Decadal Survey. The EarthFinder concept is based on a dramatic shift in our understanding of how PRV measurements should be made. We propose a new paradigm which brings the high precision, high cadence domain of transit photometry as demonstrated by Kepler and TESS to the challenges of PRV measurements at the cm/s level. This new paradigm takes advantage of: 1) broad wavelength coverage from the UV to NIR which is only possible from space to minimize the effects of stellar activity; 2) extremely compact, highly stable, highly efficient spectrometers (R>150,000) which require the diffraction-limited imaging possible only from space over a broad wavelength range; 3) the revolution in laser-based wavelength standards to ensure cm/s precision over many years; 4) a high cadence observing program which minimizes sampling-induced period aliases; 5) exploiting the absolute flux stability from space for continuum normalization for unprecedented line-by-line analysis not possible from the ground; and 6) focusing on the bright stars which will be the targets of future imaging missions so that EarthFinder can use a ~1.5 m telescope

    The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report

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    The Habitable Exoplanet Observatory, or HabEx, has been designed to be the Great Observatory of the 2030s. For the first time in human history, technologies have matured sufficiently to enable an affordable space-based telescope mission capable of discovering and characterizing Earthlike planets orbiting nearby bright sunlike stars in order to search for signs of habitability and biosignatures. Such a mission can also be equipped with instrumentation that will enable broad and exciting general astrophysics and planetary science not possible from current or planned facilities. HabEx is a space telescope with unique imaging and multi-object spectroscopic capabilities at wavelengths ranging from ultraviolet (UV) to near-IR. These capabilities allow for a broad suite of compelling science that cuts across the entire NASA astrophysics portfolio. HabEx has three primary science goals: (1) Seek out nearby worlds and explore their habitability; (2) Map out nearby planetary systems and understand the diversity of the worlds they contain; (3) Enable new explorations of astrophysical systems from our own solar system to external galaxies by extending our reach in the UV through near-IR. This Great Observatory science will be selected through a competed GO program, and will account for about 50% of the HabEx primary mission. The preferred HabEx architecture is a 4m, monolithic, off-axis telescope that is diffraction-limited at 0.4 microns and is in an L2 orbit. HabEx employs two starlight suppression systems: a coronagraph and a starshade, each with their own dedicated instrument

    The Habitable Exoplanet Observatory (HabEx) Mission Concept Study Final Report

    Get PDF
    The Habitable Exoplanet Observatory, or HabEx, has been designed to be the Great Observatory of the 2030s. For the first time in human history, technologies have matured sufficiently to enable an affordable space-based telescope mission capable of discovering and characterizing Earthlike planets orbiting nearby bright sunlike stars in order to search for signs of habitability and biosignatures. Such a mission can also be equipped with instrumentation that will enable broad and exciting general astrophysics and planetary science not possible from current or planned facilities. HabEx is a space telescope with unique imaging and multi-object spectroscopic capabilities at wavelengths ranging from ultraviolet (UV) to near-IR. These capabilities allow for a broad suite of compelling science that cuts across the entire NASA astrophysics portfolio. HabEx has three primary science goals: (1) Seek out nearby worlds and explore their habitability; (2) Map out nearby planetary systems and understand the diversity of the worlds they contain; (3) Enable new explorations of astrophysical systems from our own solar system to external galaxies by extending our reach in the UV through near-IR. This Great Observatory science will be selected through a competed GO program, and will account for about 50% of the HabEx primary mission. The preferred HabEx architecture is a 4m, monolithic, off-axis telescope that is diffraction-limited at 0.4 microns and is in an L2 orbit. HabEx employs two starlight suppression systems: a coronagraph and a starshade, each with their own dedicated instrument.Comment: Full report: 498 pages. Executive Summary: 14 pages. More information about HabEx can be found here: https://www.jpl.nasa.gov/habex

    Mind the \u27Gap,\u27 Modern Creationism and the KJB

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    Despite the scientific community’s overwhelming support for an evolutionary explanation of the origins of the universe, nearly half of the American public believes in biblical creationism. This disjunction between scientific authority and popular religion is striking because it signifies that many place the inerrancy of the Bible and a literal reading of the book of Genesis above the findings of the mainstream scientific community. Most contemporary creationists hold to “Young Earth” creationism, the theory that God created the universe in six literal, twenty-four days no more than 6-10,000 years ago. But creationism in the first decade of the twenty-first century differs greatly from creationism a century ago. By the late nineteenth century, a majority of creationists believed in a geologically ancient earth. For most evangelicals, young earth creationism seemed passé, out of touch with recent geological discoveries. Instead, these old earth creationists adopted one of two approaches to accommodate the fossil record. “Day Age” creationism made room for the geological ages by proposing that each individual day of creation actually represented a period of thousands, or even millions, of years. The counter position among creationists was the “Gap Theory” in which the Genesis account of creation described two distinct creative acts, separated by a period of time during which geological strata and the fossil record could have accumulated. This paper will show that the Gap Theory—the most prevalent creationist belief at the turn of the twentieth century—could not have existed but for a translation decision made by the King James Translators regarding Genesis 1:1. The translators relied upon medieval rabbinical sources in translating the Old Testament, but the rabbis differed over whether or not Genesis 1:1 should begin with a dependent or an independent clause. If the King James Bible translators had opted for a dependent clause “In the beginning of God’s creating…” instead of the independent clause, “In the beginning, God created…” the Gap Theory would not have been a viable alternative for creationists three hundred years later. If that had been so, more evangelicals would have opted for theistic evolutionism (or its cousin, the Day Age Theory) rather than defending the unpopular Young Earth Theory of creation. Without a viable Gap Theory, it is likely that fewer evangelicals would today be young earth creationists. The Gap Theory acted as a kind of “ark,” allowing evangelicals to harmonize their belief in biblical inerrancy with modern scientific discoveries without having to acknowledge the theory of evolution. Thus, when Young Earth Creationism rebounded in the 1960s, Gap Theorists were able to smoothly transition to Young Earth Creationism

    Referate

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