Presentation #515.04 in the session Mars Surface (iPosters).
Hyperspectral images recorded from planetary mission spectrometers provide various illumination and observation angles of planetary surfaces. These instruments provide us with data that allows us to study their properties of surface materials. For the best interpretations of those data, these observations frequently need to be compared to laboratory measurements. One such measurement that has not been made before is the bidirectional reflectance distribution function (BRDF) of CO2 ice, an atmospheric constituent of Mars that seasonally covers latitudes from ~50° to the poles in each hemisphere. Additionally, Mars has a South Polar Residual Cap (SPRC) that persists throughout the warmest months on the planet. At Mars, Remote-sensing spectrometers such as the Compact Reconnaissance Imaging Spectrometer (CRISM) flown on Mars Reconnaissance Orbiter (MRO) provides hyperspectral images of the seasonal cap and the SPRC.
At York University, we generate CO2 ice in our environmental chamber that can control and maintain a stable pressure and temperature as low as 1 mbar and 140 K. This allows us to simulate the Martian polar conditions. Under various pressure and temperature regimes, we can simulate environments that are analogous to the seasonal changes of Mars and then perform spectral measurements to compliment CRISM observations.
In previous work we have successfully grown CO2 ice under Martian conditions. We have measured the albedo using an infrared camera and reflectance of the ice with our spectrometer. We have also observed various CO2 ice textures under various pressure and temperature changes. When CO2 ice deposits on our cold plate it forms in one of two modes: transparent slab ice, or fine-grained frost. These modes were expected as they resemble the CO2 ice found at the SPRC of Mars. When activating our heater, we observed fracturing and healing, potentially analogous to the formation of jets on the Cryptic Terrain found at the south pole of Mars.