The Mercury Atmospheric and Surface Composition Spectrometer for the MESSENGER Mission |
| |
Authors: | William E McClintock Mark R Lankton |
| |
Institution: | (1) Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, USA |
| |
Abstract: | The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) is one of seven science instruments onboard the MErcury
Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft en route to the planet Mercury. MASCS consists
of a small Cassegrain telescope with 257-mm effective focal length and a 50-mm aperture that simultaneously feeds an UltraViolet
and Visible Spectrometer (UVVS) and a Visible and InfraRed Spectrograph (VIRS). UVVS is a 125-mm focal length, scanning grating,
Ebert-Fastie monochromator equipped with three photomultiplier tube detectors that cover far ultraviolet (115–180 nm), middle
ultraviolet (160–320 nm), and visible (250–600 nm) wavelengths with an average 0.6-nm spectral resolution. It will measure
altitude profiles of known species in order to determine the composition and structure of Mercury’s exosphere and its variability
and will search for previously undetected exospheric species. VIRS is a 210-mm focal length, fixed concave grating spectrograph
equipped with a beam splitter that simultaneously disperses the spectrum onto a 512-element silicon visible photodiode array
(300–1050 nm) and a 256-element indium-gallium-arsenide infrared photodiode array 850–1,450 nm. It will obtain maps of surface
reflectance spectra with a 5-nm resolution in the 300–1,450 nm wavelength range that will be used to investigate mineralogical
composition on spatial scales of 5 km. UVVS will also observe the surface in the far and middle ultraviolet at a 10-km or
smaller spatial scale. This paper summarizes the science rationale and measurement objectives for MASCS, discusses its detailed
design and its calibration requirements, and briefly outlines observation strategies for its use during MESSENGER orbital
operations around Mercury. |
| |
Keywords: | Atmosphere Exosphere Mercury MESSENGER Spectrometer Surface |
本文献已被 SpringerLink 等数据库收录! |
|