The lunar phase curve in the near ultraviolet
We present results from an ongoing program to perform UV measurements of the Moon at varying solar phase angles to understand the lunar phase curve at ultraviolet wavelength.
Moon↗
Engineering topics
Hendrix, A. R.
Publications and source records attributed to Hendrix, A. R..
The Lunar Phase Curve in the Near Ultraviolet
We present results from an ongoing program to perform UV measurements (215.0 and 237.0 nm) of the Moon at varying solar phase angles to understand the lunar phase curve at ultraviolet wavelengths. We use new observations from the Ultraviolet Spectrometer (UVS) aboard the Student Nitric Oxide Explorer (SNOE) combined with existing observations from the Galileo UVS. The lunar UV phase curve can be used to further understand the scattering properties of the lunar surface. The Moon's scattering properties at visible wavelengths are well understood; studying scattering properties at shorter wavelengths may provide insight into the roles of volume scattering vs. surface scattering and how weathering processes may affect scattering properties. The UV lunar phase curve can also be helpful for UV observers, as the Moon is often used as a UV calibration source, but the UV brightness variation with phase angle has not been well understood.
Hendrix, A. R.↗
Ultraviolet Surface Properties of the Icy Galilean Satellites from Phase Curve Analysis
In this study, we use ultraviolet observations from the International Ultraviolet Explorer (IUE) and the Galileo Ultraviolet Spectrometer (UVS) to compose the ultraviolet solar phase curves of the icy Galilean satellites. Broadband rotation phase curves from 0.26 to 0.32 microns are constructed in order to examine the rotational behavior of the icy Galilean satellites in the ultraviolet. After normalizing the rotational variations, modeling of the solar phase variations are compared to comparable studies in the visible.
Hendrix, A. R.↗
Vesta's UV lightcurve: hemispheric variation in brightness and spectral reversal
We investigate Vesta's UV lightcurve and spectral reversal. We model the UV spectra using laboratory spectra of howardite and diogenite meteorites, as well as suing candidate materials based on knowledge of Vesta's composition from visible and near-infrared spectroscopy.
Vesta↗
Vesta as Seen by IUE and HST: Correlations in UV Brightness with Topography and Composition
A reanalysis of IUE spectra of Vesta indicates longitudinal variations in a UV absorption feature that may be related to compositional and/or topographic variations, as revealed by recent HST maps.
Hendrix, A. R.↗
Hydrogen peroxide on the surface of Europa
Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.
Non-programmatic↗