The Miniature
Thermal Emission Spectrometer
The Thermal Emission Spectrometer (TES) is an instrument on board Mars Global Surveyor. TES collects two types of data, hyperspectral thermal infrared data from 6 to 50 micrometres (μm) and bolometric visible-NIR (0.3 to 2.9 μm) measurements. TE ...
(Mini-TES) is an
infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
spectrometer
A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...
used for detecting the composition of a material (typically rocks) from a distance. By making its measurements in the
thermal infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...
part of the
electromagnetic spectrum
The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies.
The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from ...
, it has the ability to penetrate through the dust coatings common to the Martian surface which is usually problematic for remote sensing observations. There is one on each of the two
Mars Exploration Rovers.
Development
The Mini-TES was originally developed by
Raytheon for the Department of Geological Sciences at
Arizona State University
Arizona State University (Arizona State or ASU) is a public research university in the Phoenix metropolitan area. Founded in 1885 by the 13th Arizona Territorial Legislature, ASU is one of the largest public universities by enrollment in the ...
. The Mini-TES is a miniaturized version of Raytheon's
Mars Global Surveyor (MGS) TES, built by Arizona State University and Raytheon SAS’ Santa Barbara Remote Sensing. The MGS TES data helped scientists choose landing sites for the Spirit and Opportunity Mars explorer rovers.
Martian soil
The Mini-TES is used for identifying promising rocks and soils for closer examination, and to determine the processes that formed Martian rocks. It measures the infrared radiation that the target rock or object emits in 167 different wavelengths, providing information about the target's composition. One particular goal is to search for minerals that were formed by the action of water, such as carbonates and clays. The instrument can also look skyward to provide temperature profiles of the Martian atmosphere and detect the abundance of dust and water vapor.
The instrument is located inside the warm electronics box in the body of the rover - the mirror redirects radiation into the aperture from above. The Mini-TES instruments aboard the MERs Opportunity and Spirit were never expected to survive the cold Martian winter even if the rovers themselves survived. It was thought that a small
potassium bromide
Potassium bromide ( K Br) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion (sodium bromide is equall ...
(KBr)
beamsplitter which was housed in an aluminium fitting would crack due to the mismatched
coefficient of thermal expansion. This never happened however and the miniTES instrument on both rovers has survived several Martian winters, and the Spirit rover continues to periodically use the Mini-TES for remote sensing. (The miniTES on the Opportunity rover is not currently being used because of accumulated dust on the mirror following the 2007 dust storm
).
There are two other types of spectrometers mounted on the
rover
Rover may refer to:
People
* Constance Rover (1910–2005), English historian
* Jolanda de Rover (born 1963), Dutch swimmer
* Rover Thomas (c. 1920–1998), Indigenous Australian artist
Places
* Rover, Arkansas, US
* Rover, Missouri, US
* ...
's arm which provide additional information about the composition when the rover is close enough to touch the object.
Mini-Tes can work with
Pancams to analyze surroundings.
The Mini-TES weighs 2.1 kg (4.6 lb)
of the total 185 kg (408 lb) for the whole rover.
See also
*
Heat Flow and Physical Properties Package (included an infrared radiometer)
References
External links
NASA JPL web-page stating purpose of Mini-TESTechnical academic publication on Mini-TES for Mars Exploration Rover
{{Mars
Mars Exploration Rover mission
Spectrometers
Spacecraft instruments