A Laboratory Study on End-Member Mixing for the Deconvolution of Spectra Measured from VEM on NASA VERITAS Mission

Kurzfassung

In June 2021, NASA selected the VERITAS and DAVINCI missions under the Discovery program) and ESA selected the mission EnVision (under the Cosmic Vision plan) to study the planet Venus. All three missions will collect data to help scientists understanding how Venus geology has evolved over time, what geologic processes are still active on its surface, and if water was ever present. VERITAS is designed to gather global, high-resolution topography and imaging of Venus' surface and produce the first maps of global surface composition, thermal emissivity, and gravity fields. Onboard the spacecraft will be two scientific instruments, the Venus Emissivity Mapper (VEM) and Venus Interferometric Synthetic Aperture Radar (VISAR). VEM will map the Venus surface emissivity using six spectral bands in five atmospheric windows that see through the CO2-rich clouds. VEM also carries eight additional bands for calibration and detection of near-surface water vapor. The Planetary Spectroscopy Laboratory (PSL) is operated by the VEM PI-team. It is the only facility in the world capable of acquiring emissivity spectra of Venus analogs in vacuum at Venus surface temperatures (routinely 400°, 440°, and 480°C), and hemispherical reflectance (in vacuum at 25°C) in the VEM spectral range. We present here results on spectra of binary mixtures of end-members to improve our understanding of mixing properties at this wavelength and assist with interpretation of VEM data.