The moons of Uranus: A NIRSpec investigation of their origins, organic constituents, and possible ocean world activity

We propose to observe the leading and trailing hemispheres of the Uranian moons Ariel, Umbriel, Titania, and Oberon using NIRSpec IFU (G395M, 2.87 - 5.27 microns) to determine whether NH3-rich species, organics, and carbonates are present and measure CO2 ice and H2O ice features on these moons. These observations will provide an ideal opportunity to investigate the spectral evidence for past ocean world activity on these moons, assess the organic constituents on their surfaces, and measure carbon and hydrogen isotopes to assess the formation conditions in the Uranian subnebula. These science goals are highly challenging to investigate with ground-based facilities because of strong overprinting telluric bands over the 2.9 to 3.5 microns wavelength range. Furthermore, Earth's atmosphere is opaque between 4.2 and 4.5 microns, making detection and measurement of the 4.27-micron CO2 ice band on the Uranian moons and other planetary surfaces impossible to do using ground-based facilities. JWST is therefore the only existing facility that can make these observations. We require 9.96 hours of science time, and 20.72 hours of total charged time, to make the eight observations required to complete this project's science objectives. These observations will generate an important dataset that will inform the spectroscopic priorities of future spacecraft mission concepts that aim to explore Uranus and its moons.