Planetary atmosphere observation analysis

Abstract:

The recent discovery of three Earth-sized, potentially habitable planets around a nearby cool star, TRAPPIST-1, has provided three key targets for the upcoming James Webb Space Telescope (JWST). Depending on their atmospheric characteristics and precise orbit configurations, it is possible that any of the three planets may be in the liquid water habitable zone, meaning that they may be capable of supporting life. We find that present-day Earth levels of ozone, if present, would be detectable if JWST observes 60 transits for innermost planet 1b and 30 transits for 1c and 1d.

Abstract:

We place upper limits on lunar olivine abundance using midinfrared (5–25 µm) data from the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment (Diviner) along with effective emissivity spectra of mineral mixtures in a simulated lunar environment. Olivine-bearing, pyroxene-poor lithologies have been identified on the lunar surface with visible-near-infrared (VNIR) observations. Since the Kaguya Spectral Profiler (SP) VNIR survey of olivine-rich regions is the most complete to date, we focus this work on exposures identified by that study. We first confirmed the locations with VNIR data from the Moon Mineralogy Mapper (M3) instrument. We then developed a Diviner olivine index from our laboratory data which, along with M3and Lunar Reconnaissance Orbiter Camera wide-angle camera data, was used to select the geographic area over which Diviner emissivity data were extracted. We calculate upper limits on olivine abundance for these areas using laboratory emissivity spectra of anorthite-forsterite mixtures acquired under lunar-like conditions. We find that these exposures have widely varying olivine content. In addition, after applying an albedo-based space weathering correction to the Diviner data, we find that none of the areas are unambiguously consistent with concentrations of forsterite exceeding 90 wt %, in contrast to the higher abundance estimates derived from VNIR data.