Spectroscopy from Space

Abstract

This chapter reviews detection of materials on solid and liquid (lakes and ocean) surfaces in the solar system using ultraviolet to infrared spectroscopy from space, or near space (high altitude aircraft on the Earth), or in the case of remote objects, earth-based and earth-orbiting telescopes. Point spectrometers and imaging spectrometers have been probing the surfaces of our solar system for decades. Spacecraft carrying imaging spectrometers are currently in orbit around Mercury, Venus, Earth, Mars, and Saturn, and systems have recently visited Jupiter, comets, asteroids, and one spectrometer-carrying spacecraft is on its way to Pluto. Together these systems are providing a wealth of data that will enable a better understanding of the composition of condensed matter bodies in the solar system. Minerals, ices, liquids, and other materials have been detected and mapped on the Earth and all planets and/or their satellites where the surface can be observed from space, with the exception of Venus whose thick atmosphere limits surface observation. Basaltic minerals (e.g., pyroxene and olivine) have been detected with spectroscopy on the Earth, Moon, Mars and some asteroids. The greatest mineralogic diversity seen from space is observed on the Earth and Mars. The Earth, with oceans, active tectonic and hydrologic cycles, and biological processes, displays the greatest material diversity including the detection of amorphous and crystalline inorganic materials, organic compounds, water and water ice.

Ocean worlds in the outer solar system

“…Ammonia has been detected directly at Enceladus [ Waite et al , ] and may be the ultimate source of the N 2 in Titan's atmosphere [ Glein , ]. Ammonia ice has been identified spectroscopically at Charon and some of the Saturnian satellites, but not in the Jovian moons [ Clark et al , ]. This apparent absence of NH 3 is consistent with the expected higher temperatures during accretion of Jupiter satellites compared with the satellites of Saturn [ Lunine and Stevenson , ].…”

Sentinel-MSI VNIR and SWIR Bands Sensitivity Analysis for Soil Salinity Discrimination in an Arid Landscape

“…To enhance these absorption features, many approaches were proposed, such as the relative absorption-band-depth [35], the spectral feature fitting technique [36], and the Tricorder and Tetracorder algorithms [37,38]. These approaches work on so-called CRRS, thus acknowledging that the absorption in a spectrum has two components: a continuum and individual features [24,34,39]. A continuum is a mathematical function used to isolate a particular absorption feature for analysis.…”

Multi- and hyperspectral spaceborne remote sensing of the Aggeneys base metal sulphide mineral deposit sites in the Lower Orange River region, South Africa

“…Additional characteristic absorption features are treated in a similar manner. This process (Clark et al, 1987) now facilitates further qualitative and quantitative analysis because only the material characteristic absorption features (Hunt and Ashley, 1979;Townsend, 1987) are used in the analysis of the data (Clark et al, 2014). This preprocessing step is carried out on a spectral reference database, such as the USGS digital spectral library (Clark et al, 2007), which contains mineralogical wellcharacterized reference spectra that serve as reference standards for a later comparison of the reference spectrum to an unknown spectrum (e.g.)…”