September 2022 – Page 6 – My WordPress Site

Schematic diagrams highlighting the interesting components of emission from a binary neutron star merger at two different temporal and spatial scales. In (a), the system is shown at sub-parsec scales and within the first few years after the merger. The locations of gamma-ray emission in the dynamical ejecta and the cocoon surrounding the jet are highlighted, as well as the X-ray emission from the interaction between the jet and the interstellar medium (ISM). While the jet and cocoon emission are short-lived, the afterglow produces continuum emission for many years. Only the emitted X-rays produce the fluence that could be lethal. The kilonova, i.e., the UV/optical/IR emission powered by radioactivity in the ejecta, is also shown for additional context, but is undetectable after a week. In (b), the larger, late-time structure of the remnant is shown with the long-since dissipated jet location indicated. The explosion from the merger will launch a strong shock that sweeps out a bubble-like structure as it expands through the ISM, which is a source of potentially threatening cosmic rays. -- astro-ph.HE

Biogeochemical Cycles & Geobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life

The Evolution And Spread Of Sulfur-cycling Enzymes Reflect Volcanic Sulfur Sources And The Redox State Of The Early Earth

by Keith CowingSeptember 18, 2022September 16, 2022

view of Hydraotes Chaos (white outline), including the location of the proposed mud lake (black arrow) -- PSI

Away Teams & Field Reports, Caves, Craters, Mountains & Lava Tubes, Imaging & Spectroscopy, Tricorders & Sensors

Tricorder Tech: NASA Astrobiology Field Research With A Hand-held X-ray Fluorescence Field Spectrometer

by Keith CowingSeptember 16, 2022December 17, 2023

Example images of HIP 65426 (top panels) and HD 116084 (bottom panels) before and after bad pixel correction (left and right panels, respectively). The color scale has been stretched so that it ranges from 0 to 1% of the peak counts in each image. Residual striping features are seen in the HD 116084 images, which we discuss in Section 4.1. The pixel size in all images is 65 mas, for a total field of view of 5.2 × 5.2 arcseconds. -- astro-ph.EP

Europa, Missions & Hardware

NASA ROSES-22 Amendment 50: C.27 Precursor Science Investigations for Europa Final Text and Due Dates

by Keith CowingSeptember 16, 2022September 16, 2022

Simulated nicotinic acid abundances compared to measured values in carbonaceous chondrites and asteroid (162173) Ryugu. A rock density of 3 g cm−3 , a porosity of 0.2, [56–58] and an ice density of 0.917 g cm−3 completely filling the pores (after all radionuclides have decayed and aqueous activity has ceased) were assumed as the properties of the planetesimal/carbonaceous chondrite hosting the chemical synthesis. The simulations were run at a pressure of 100 bar. From left to right, the plotted bars show the simulated molecular abundance of nicotinic acid (solid black line on the very left) for the whole temperature range of liquid water, as well as the abundances measured in samples of Cb asteroid (162173) Ryugu collected during the Hayabusa2 spacecraft mission, [14] in the CI chondrite Orgeil, [14] several Antarctic CM2 chondrites, [12] the CM2 chondrites Murchison and Murray, and the ungrouped C2 chondrite Tagish Lake [13] as lines and shaded ranges described in the legend. Each time, the measured nicotinic acid abundance and the sum of all isomers (nicotinic acid, isonicotinic acid, picolinic acid) are given, since thermochemical equilibrium simulations cannot distinguish between isomers. The type of extraction method used (hot water, cold water ultrasonication, HCl-hydrolyzed, formic acid) is denoted next to each panel. A tabulated version of the data presented here is available in the Supporting Information in Table S1. -- astro-ph.EP

Biosignatures & Paleobiology, Missions & Hardware, Tricorders & Sensors

Tricorder Tech: Solid-State Single-Molecule Sensing With The Electronic Life-detection Instrument For Enceladus/Europa (ELIE)

by Keith CowingSeptember 16, 2022September 16, 2022

Transmission spectra of GJ 1132 b from all three data reduction pipelines and both visits. Upper panel: the Eureka! (yellow), FIREFLy (pink), and ExoTiC-JEDI (blue) reductions are shown for both visits at R∼100. Also shown are the differences between reductions (solid, dashed, and dotted gray lines) in units of σ, demonstrating the agreement between pipelines within a single visit. A ±1σ shaded region is overlaid. Bottom panel: the Eureka! reduction for both visits, with the NIRSpec detector gap denoted by the shaded gray region. The shaded yellow regions show two important wavelength ranges that differ the most between the visits (see Sections 4.1 and 4.4.1 for further discussion on these differences). -- astro-ph.EP

Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy

The Impending Opacity Challenge in Exoplanet Atmospheric Characterization

by Keith CowingSeptember 15, 2022September 15, 2022

𝐼 and 𝑄 Stokes parameters for silicate grains measured at 220 GHz at the South magnetic pole (top) and at the equator (bottom) aligned with respect to the solar radiation field (𝑘-alignment). We note that maps at both values of 𝛼 reproduce the spurious patterns seen in the temperature maps in Fig. 6, being the ones in the 𝛼 = −2.0 due to higher opacities and boundary effects, and the strike patterns seen in the 𝛼 = −3.5 maps only due to statistical fluctuations in the spatial generation of the photon packages, resulting in negligible spatial variations in the 𝐼 and 𝑄 magnitudes. Maps for the South magnetic pole are identical to those of the equator, since both configurations are equivalent. Negative values of 𝑄 are due to the linear polarization along the 𝑌 axis of the image. -- astro-ph.EP

Discovery Of Interstellar 2-Cyanoindene (2-C9H7CN) In GOTHAM Observations of TMC-1

by Keith CowingSeptember 15, 2022September 15, 2022

Mass-radius diagram for TOI-1801 b, together with all known exoplanets (grey dots) with a precision better than 8% in radius (through transit) and 20% in mass (from RV). The population of young transiting exoplanets (< 900 Myr) with measured masses is plotted as coloured dots, according to their ages. The uncertainties on TOI-1801 b are shown as coloured shaded regions with 1, 2, and 3σ levels of confidence. In the left panel, the iso-density lines are displayed as dashed grey lines. In the remaining panels where the population of exoplanets is plotted along with TOI-1801 b, coloured lines indicate different composition models without gas (middle panel) and with a gas envelope (right panel) from Zeng et al. (2019). In the right panel, the solid and dotted lines show the models with temperatures of 300 K and 500 K, respectively, of the corresponding specific entropy at 100 bar level in the gas envelope. The Earth and Neptune are also depicted as reference. We include B22 and M22 as references because different results have been published for the same planet, and this refers to Barragán et al. (2022) and El Mufti et al. (2023), respectively. -- astro-ph.EP

Different Degrees Of Nitrogen And Carbon Depletion In The Warm Molecular Layers Of Protoplanetary Disks

by Keith CowingSeptember 15, 2022September 15, 2022

Mercury

NASA Astrobiology Program

In Memoriam: Sherwood Chang

by Keith CowingSeptember 15, 2022September 15, 2022

Side view of the ejecta curtain created during a hypervelocity impact experiment at the NASA Ames Vertical Gun Range. The experiment was designed to investigate the effects of impacts on Ceres’ organics. Credit: NASA / Johns Hopkins University Applied Physics Laboratory

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Imaging & Spectroscopy, Mars

Perseverance Rover Conducts Astrobiology And Geology Exploration On Mars

by Keith CowingSeptember 15, 2022April 14, 2024

Perseverance At Work

Analog Studies, Astrogeology, Caves, Craters, Mountains & Lava Tubes, Imaging & Spectroscopy, Tricorders & Sensors

Tricorder Tech: NASA Goddard Instrument Field Team Tests Astrobiology Instrumentation

by Keith CowingSeptember 14, 2022December 17, 2023