The United Arab Emirates' (UAE) Mars mission that launched about a year ago has recently captured the most detailed images of auroras in the Martian sky.
The optics used to capture these images include a silicon carbide-coated mirror and diffraction grating for the Emirates Mars Ultraviolet Spectrometer (EMUS) that were developed by researchers at Lawrence Livermore National Laboratory (LLNL) and collaborators at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado.
The Hope Probe is designed to study Mars’ atmosphere across all its layers and at a global scale throughout the different seasons over the course of a Martian year. But the new finding is outside that main science plan and occurred even before the probe's formal science mission had begun, when scientists were testing the instruments on the spacecraft. In images from EMUS, scientists easily spotted the highly localized nightside aurora that scientists have struggled to study at Mars for decades.
“Typical planetary ultraviolet spectrometers are unable to measure emissions located at wavelengths shorter than about 115 nanometers,” said Greg Holsclaw, EMUS instrument scientist. “LLNL’s silicon carbide coating, applied to half the optic area and used in combination with a windowless, photon-counting detector, allows EMUS to access an emission at 102.6 nm that is produced by the extended hydrogen exosphere of Mars. This brings new and complementary information to the hydrogen emission at 121.6 nm that is more commonly observed.”
The optics are part of the far-ultraviolet imaging spectrograph that aims to study the Martian atmosphere in the 100-170 nanometer spectral range. The Hope Probe is the first Mars orbiter to carry a spectrometer that is sensitive to wavelengths below 121 nanometers. EMUS will be used to investigate how conditions throughout the Mars atmosphere affect rates of atmospheric escape, and how key constituents in the exosphere behave temporally and spatially.