A temperature map of the nucleus with different spatial resolutions. The
context image (in black and white) is a HRIVIS image taken just before
impact. The color bar in the middle gives temperature in Kelvins. The sun
is to the right in all images.
These data were acquired with the IR spectrometer using signal between
1.8 and 2.2 µm and modeled to contain both a reflected and an emitted
component. After this model is applied, the resulting number is a
temperature which is represented by different colors with red being the
highest and purple the coldest.
The derived temperature varies from 260 +/- 6K to 329 +/- 8K. Shadows are
the coolest temperatures, and the point directly below the sun is hottest.
These temperatures indicate that the thermal inertia of the surface (the
quality of the surface describing the ability to conduct and store heat)
is low. In other words, on Tempel 1, it is hot in the sun and cold in the
shadows. A value for thermal inertia is estimated at <100 W/K/m2/s1/2.