• Miniature Thermal Emission Spectrometer
  • MISSION: Mars Exploration Rovers
  • Launch: July 2003
  • Arrival: January 2004
  • Currently: Lost contact

What was Mini-TES?

The Athena package was composed of several science instruments on the twin 2003 Mars Exploration rovers Spirit and Opportunity. One of the Athena instruments was the Mini-TES, short for Miniature Thermal Emission Spectrometer, which characterized the martian terrain around the rovers using thermal infrared spectroscopy.

What did it do?

The Mini-TES instrument captured temperature and emissivity data, which was used to determine the mineralogy of the martian surface materials. This enabled the rover science team to find promising sites at a distance, and select places for the rovers to examine more closely with its other instruments.

Why was it significant?

Making measurements in the thermal infrared has many advantages for a Mars rover. The thermal IR has the ability to penetrate through the dust coatings common to the martian surface that can present problems for remote sensing observations made at visual wavelengths. Mini-TES was able to recognize carbonates, silicates, organic molecules, and minerals formed in water. Thermal IR data also helped scientists assess the capacity of rocks and soils to hold heat over the wide temperature range of a martian day.

Science Objectives

  • Determine the mineralogy of rocks and soils.
  • Determine the thermophyscial properties of selected soil patches.
  • Determine the temperature profile, dust and water-ice opacity, and water vapor abundance in the lower atmospheric boundary layer.
On June 10, 2003, the first Mars Exploration Rover Spirit was launched on a Delta II rocket from Cape Canaveral, Florida. After a seven month flight, it entered the martian atmosphere in January 3, 2004. The second lander and rover, Opportunity, followed on January 24. After entering the atmosphere, the rovers deployed parachutes and airbags, hitting the surface and bouncing back up a hundred feet in the martian air. After finally settling down, the airbags deflated and the lander petals opened to reveal the rovers folded inside like origami. The rovers unfolded themselves carefully, deploying their camera masts, antennae, wheels, and solar arrays. Each rover was able to take a 360-degree visible color and infrared image panorama. Athena scientists chose rock and soil targets and commanded the rovers to explore their surroundings. When either rover reached a target, its multi-jointed arm deployed and the target was examined with a microscopic "hand lens" and two spectrometers. The original mission plan called for the rovers to operate for around 90 sols (martian days), but both lasted much longer. Spirit operated for 2623 sols (until March 2010), while Oppportunity ceased responding in June 2018 after 5111 sols.

Meet the Group

Principal Investigator

  • Philip Christensen, Principal Investigator
  • Arizona State University

Engineering Team

  • Greg Mehall
  • Arizona State University
  • Saadat Anwar
  • Arizona State University
  • George Cannon
  • Arizona State University
  • Noel Gorelick
  • Arizona State University
  • Rolph Kheen
  • Arizona State University
  • Tom Tourville
  • Arizona State University
  • Duane Bates
  • Raytheon Santa Barbara Remote Sensing
  • Steven Ferry
  • Raytheon Santa Barbara Remote Sensing
  • Teresa Fortuna
  • Raytheon Santa Barbara Remote Sensing
  • John Jeffryes
  • Raytheon Santa Barbara Remote Sensing
  • William O'Donnell
  • Raytheon Santa Barbara Remote Sensing
  • Richard Peralta
  • Raytheon Santa Barbara Remote Sensing
  • Steven Silverman
  • Raytheon Santa Barbara Remote Sensing
  • Thomas Wolverton
  • Raytheon Santa Barbara Remote Sensing
  • Diana Blaney
  • Jet Propulsion Laboratory
  • Robert Denise
  • Jet Propulsion Laboratory
  • Joel Rademacher
  • Jet Propulsion Laboratory
  • Richard Morris
  • Cornell University
  • Steven Squyres
  • Cornell University


    Frequently Asked Questions

    • What is Mini-TES?

      The Miniature Thermal Emission Spectrometer (Mini-TES) will provide remote measurements of mineralogy and thermophysical properties of the landscape around the Mars Exploration Rovers, and guide the Rovers to key targets for detailed investigation by other Rover experiments.

      Mini-TES collects high-resolution infrared spectra that will help identify the mineralogy of all geologic materials including silicates, carbonates, sulfates, phosphates, oxides and hydroxides. Mini-TES will also measure the lower atmospheric boundary layer and provide information on suspended dust, water ice, and water vapor opacity.

      The Mini-TES is a miniaturized version of the Thermal Emission Spectrometer (TES) built by Arizona State University and Raytheon Santa Barbara Remote Sensing for the Mars Observer and Mars Global Surveyor missions.

    • Why are we exploring Mars?

      Mars has a fascinating and diverse terrain including polar ice caps, dry river valleys, volcanoes, canyons and craters. While we’ve already visited the planet several times before, there is still much more to learn. Of all the planets in our solar system, Mars is perhaps the most earthlike, and it may be the best location to search for extraterrestrial life.

    • Why is the search for water on Mars so important?

      The main scientific objective for both rovers is to investigate Martian geologic history and understand what role water played in it.

      Water is a basic requirement for the origin and continued existence of life. Determining how much — and how long liquid water existed on the planet’s surface are fundamental questions in our search for evidence of past or present life on Mars.

    • How will mini-TES help determine if Mars once had water?

      The mini-TES instrument is a 167 channel, high resolution, infrared spectrometer that can directly identify minerals around the landing sites.

      In Gusev Crater, mini-TES will look for minerals like carbonates and sulfates that form only in the presence of water. Finding them will provide strong evidence that Gusev was once a lake.

      In Meridiani Planum, mini-TES will help determine how the mineral gray hematite formed. On earth, gray hematite usually forms in the presence of water. At Meridiani, mini-TES will search for the minerals goethite and magnetite. If goethite is found, the area almost certainly once had water. If goethite is not present but magnetite is, the hematite formed under dry conditions.

    • What instruments besides mini-TES are on the landers?

      Each lander will deploy a solar powered Mars Exploration Rover vehicle that will explore its surroundings for several months using a variety of scientific tools.

      These include a color stereo camera, a microscope, and three unique spectrometers that will determine the mineral and elemental composition of the rocks and soils.

      The color camera will search for layered rock deposits and other past evidence of flowing or standing water.

      The rover’s microscope will examine the granular structure within the area’s rocks and soils. Water-borne particles have a smoother, rounded appearance, while fresh volcanic ash has sharper, angular grains.

    • Why is NASA landing in Gusev Crater?

      While some areas, such as rugged canyon floors or volcano calderas might be exciting to explore, they’re just too difficult and dangerous to land on.

      The landing sites chosen for the Rovers provide the right combination of safety and interesting science.

      Some scientists believe water from a large basin lying farther south turned Gusev into a lake that persisted for millions of years. A large channel called Ma’adim Vallis may once have carried water into the lake. Where the channel intersects the crater’s southern rim, we see eroded terrain that may be ancient river delta deposits.

    • Why is NASA landing in Meridiani Planum?

      While some areas, such as rugged canyon floors or volcano calderas might be exciting to explore, they’re just too difficult and dangerous to land on.

      The landing sites chosen for the Rovers provide the right combination of safety and interesting science.

      The landing site falls within an area equivalent in size to the state of Ohio that displays the spectral signature of the iron oxide mineral gray hematite.

      This was a major discovery of the Thermal Emission Spectrometer instrument, because on earth, hematite usually forms in conjunction with water.

    • How did Mini-TES get to Mars?

      On June 10th, 2003 NASA launched a Delta 2 rocket carrying Spirit –the first of two Mars Exploration Rovers on a mission to the Red Planet.

      27 days later, on July 7th, Spirit’s robot twin, named Opportunity, was launched in pursuit. It will take both spacecraft about 208 days to make the 300 million mile journey to Mars.

      Each spacecraft carries a rover with its own mini-TES instrument on board.

      After traveling through space for nearly seven months, Spirit arrived at Mars and touched down just south of the equator inside the 90-mile wide in Gusev Crater on January 3rd 2004 (PST). Opportunity is scheduled to land on January 24th 2004 in Meridiani Planum at a point 2 degrees south of the Martian equator.

    • Where are Mini-TES and the Spirit rover now?

      We believe Spirit is in the area pointed to by the arrow in this image.

    • Where are Mini-TES and the Opportunity rover now?

      Opportunity is currently approaching Mars, and is expected to land on January 24.

    • What else do scientists already know about Gusev Crater?

      Gusev is a windswept, 90-mile wide impact crater that formed between 3 and 4 billion years ago. The Mars Orbiter Laser Altimeter (MOLA) instrument has compiled topographic maps of the area that show the crater is only a little over 1 mile deep.

      We know a 2-mile thick layer of material covers Gusev’s floor, because a fresh impact of this size would be much deeper. Scientists are unsure if the crater floor deposits were transported by water from the Ma’adim Vallis channel lying to the south, or if the nearby volcano Apollinaris Patera filled the crater with ash.