Frequently Asked Questions


1) 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).
2) 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.
3) 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.
4) 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.
5) 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.
6) Who built THEMIS?
7) Can THEMIS detect water or ice?
Yes. Both water and ice are strongly absorbing in the IR wavelength bands THEMIS uses.
8) 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.
9) 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.