THEMIS

  • Thermal Emission Imaging System
  • MISSION: Mars Odyssey
  • Launch: April 2001
  • Arrival: October 2001
  • Currently: Orbiting Mars

What is THEMIS?

The Thermal Emission Imaging System (THEMIS) is an instrument on board the Mars Odyssey spacecraft. It combines a 5-wavelength visual imaging system with a 9-wavelength infrared imaging system.

What does it do?

The Thermal Emission Imaging System (THEMIS) is a special camera on the Mars Odyssey spacecraft. Its main tasks are mapping rock mineralogies and detecting heat, which yields information on the physical and thermal properties of the martian surface.

Why is it Significant?

THEMIS investigates the surface mineralogy and physical properties of Mars, mapping the planet using visual and infrared images. Since most geologic materials have strong fundamental vibrational absorption bands in the thermal-infrared spectral region, we are able to learn about the surface mineral composition.

Science Objectives

  • LOOK FOR ROCKS ALTERED BY WATER
  • STUDY GEOLOGIC DETAILS ON MARS
  • HUNT FOR "HOT SPOTS" INDICATING UNDERGROUND HYDROTHERMAL SYSTEMS
Mars Odyssey launched from Kennedy Space Center on April 7, 2001 and arrived at Mars on October 24, 2001. It spent the next several months achieving a circular mapping orbit by aerobraking (dipping into the atmosphere to slow and shrink the orbit). Aerobraking concluded in early February 2002, and primary mapping operations began a few weeks later. The spacecraft is in a 2-hour orbit around Mars. Mars Odyssey carries three main science instruments: The Gamma Ray Spectrometer (GRS), the Thermal Emission Imaging System (THEMIS), and the Mars Radiation Environment Experiment (MARIE).

Meet the Group

PRINCIPAL INVESTIGATOR

  • Philip Christensen
  • Arizona State University

CO-INVESTIGATORS

  • Bruce Jakosky
  • University of Colorado, Boulder
  • Hugh Kieffer
  • U.S. Geological Survey, Flagstaff (retired)
  • Kenneth Nealson
  • University of Southern California
  • Michael Malin
  • Malin Space Science Systems
  • Harry McSween
  • University of Tennessee

PARTICIPATING SCIENTISTS

  • James Bell
  • Arizona State University
  • Thomas Duxbury
  • George Mason University
  • Anton Ivanov
  • Jet Propulsion Laboratory
  • Melissa Lane
  • Planetary Science Institute
  • Jeff Moersch
  • University of Tennessee
  • Mark Richardson
  • Ashima Research
  • Tim Titus
  • U.S. Geological Survey, Flagstaff
  • Joseph Boyce
  • University of Hawaii
  • Victoria Hamilton
  • Southwest Research Institute
  • Alfred McEwen
  • University of Arizona
  • Michael Ramsey
  • University of Pittsburgh
  • Michael Smith
  • NASA Goddard Space Flight Center
  • Rebecca Williams
  • Planetary Science Institute

THEMIS MISSION MANAGER

  • Greg Mehall
  • Arizona State University

Updates

    THEMIS Discoveries

    NASA originally directed THEMIS to look for places on Mars altered by water, which it achieved. Yet the instrument’s capabilities have reached far beyond its initial mission. Below are more than a dozen additional discoveries about Mars thanks to THEMIS. Click on each to learn more.

    Frequently Asked Questions

    • What is THEMIS?

      THEMIS is a thermal emission imaging system. It contains two independent multi-spectal imaging sub-systems: a 10-band thermal infrared imager (IR), and a 5-band visible imager (VIS).

    • What's the resolution of THEMIS images?

      The IR subsystem has a resolution of 100m/pixel; the VIS subsystem has a resolution of 19m/pixel.

    • What bands does THEMIS use?

      The IR bands used by THEMIS are centered at: 6.78 microns, 6.78 microns, 7.93 microns, 8.56 microns, 9.35 microns,10.21 microns, 11.04 microns, 11.79 microns, 12.57 microns and 14.88 microns. The visible bands are centered at: 0.425 microns, 0.540 microns, 0.654 microns, 0.749 microns and 0.860 microns.

    • Why is the 6.78 micron band listed twice?

      There are 10 different filters on THEMIS, however the first two filters have the same spectral center.

    • What's up with the 14.88 micron band? It doesn't look like the others.

      At 14.88 microns, the atmosphere of Mars is opaque, so THEMIS cannot see the surface of the planet.

    • Who built THEMIS?

      The infrared-wavelength imaging portion of THEMIS was fabricated at Raytheon/Hughes Santa Barbara Remote Sensing of Goleta, California.

      The visible-wavelength camera portion of THEMIS was provided by Malin Space Science Systems of San Diego, California.

      The THEMIS telescope was manufactured by Axsys Technologies.

      THEMIS is controlled and operated from the Arizona State University campus in Tempe, Arizona.

    • Can THEMIS detect water or ice?

      Yes. Both water and ice are strongly absorbing in the IR wavelength bands THEMIS uses.

    • Can THEMIS see through dust?

      THEMIS can see through a small amount of atmospheric dust, but even a thin layer of surface dust (~100µm or 0.1mm) will obscure any underlying thermal IR signatures. Diurnal thermal conductivity can occur through several centimeters of dust, but will only increase or decrease the temperature of the dust on top.

    • When will the public get access to the THEMIS data?

      Now! The THEMIS team releases all images at the THEMIS Data Releases website and via the Planetary Data System at three-month intervals.