Albedos and spectral signatures determination and it connection to geological processes: Simile between Earth and other solar system bodies Javier Eduardo Suarez Valencia, Fabián Saavedra Daza, Luis Hernán Ochoa jaesuarezva@unal.edu.co, fsaavedrada@unal.edu.co, lhochoag@unal.edu.co Introduction Pluto In this work were used surfaces albedos, electromagnetic spectral data and satellite imagery looking to understand the glaciers dynamics in some solar system bodies; and how this is related whit their compositions and associated geological processes. By specialized software we were able to create reflectance maps and make geomorphological analysis that allows the differentiation between ice types in the glaciers and to see its interactions whit other materials. The satellite images were examined in the visible to mid-wave infrared region of the spectrum; then the spectral signatures were use to connect the reflectance whit the chemical and rheological properties of the studied compounds. The albedo or reflectance is the amount of radiation that a surface is capable of reflect in regard to the incoming radiation; if the reflected energy is big also will be the albedo (usually between 0 and 1). The DN (Digital Number) is the magnitude assigned to a pixel in the satellite images, applying a conversion factor is possible to obtain the real reflectance. Figure 3: Reflectance maps in the Sputnik Plateau region in Pluto, blue color correspond to ware ice, brown to organic mater influenced ice, and yellow to CH4 ,CO and N2 ices. Mars Method The Earth images are products of Landsat 8, the ones of Pluto were captured by the spacecraft New Horizons; both were worked using the software ArcGIS 10.1. For Mars were selected captures taken by the HiRISE cam in the MRO spacecraft (Mars Reconnaissance Orbiter) and were studied whit the software Hiview. The Nevado del Ruiz spectral signature was obtained by EO-1 satellite data processed in the software ENVI. Results Figure 4: DN distribution for the pixels in the pointed areas, every type of surface has a unique dispersion. Earth Spectral Signatures Figure 6: Spectral signature (reflectance) for Pluto surface, it can be distinguee CH4 ,CO and N2 signatures (taken from Cruikshank, 2014) . Figure 1: “Parque natural nacional de los nevados”: Visible range in the left, and the 7-4-1 band composite to the right (ideal combination for water ice detection). Figure 7: Spectral signature (reflectance) of a Martian glacier in black, CO2 spectral signature in red and H2O signature in blue (Taken from Birbring, 2004). Figure 5: Spectral signature (reflectance) for Nevado del Ruiz glacier, it can be observed similar pattern to the water ice. Conclusions • • Figure 2: Reflectance maps in the Nevado del Ruiz glacier, A) Reflectance in the NIR ( NearInfrared), B) Reflectance in the visible. References • Fengming HUI et al., (2014), Mapping blue-ice areas in Antartica using ETM+ and MODIS data. • Stern et al. (2015), The Pluto system: Initial results from its exploration by New Horizons. • Whinter (1993), Landsat TM derevied and ni situ summer reflectance of glacier in Svalbard. • Song et al (2001), Classification and Change Detection Using Landsat TM Data: When and How to Correct Atmospheric Effects?. • Cruikshank (2014), The surface composition of Pluto and Charon. • Bibring (2004), Perennial water ince identified in the south polar caps of Mars. • The reflectance for water ice bodies are very high in the visible range and low in the NIR, this relation becomes inverse in silicate materials as volcanic ashes. The last allow reflectance maps to be optimums in the identification of other materials present in glaciers of water ice; and to understand the temporal evolution of recurrent volcanic activity zones, like Nevado del Ruiz. The albedo analysis is a efficient method to differentiate materials of a heterogeneous surface; the distinct reflectance's of the ices in Pluto surface allowed a good discrimination based in the radiation that reflects every material. However, its necessary the apply of spectral signatures to obtain approximated chemical compositions of the icy bodies. The combination of this two methodologies is essential to understand the glacier dynamics in other solar system bodies. The level of correlation between the processes happening to glaciers in Earth and those in other solar system bodies rely on the surface conditions of every body; the low temperatures of Pluto drive the water ice to behave as solid rock, while other materials like CH4 ,CO and N2 behave very plastic and low resilient. In Mars the conditions aren't to different to Earth, the glaciers go trough similar processes in both planets, yet in the Martian poles CO2 ices and snow can be accumulated, allowing unique processes such as linear gullies.