Formation of smooth terrains on Comet Tempel 1

Fluidization and multiphase transport of particulate cometary material as an explanation of the smooth terrains and repetitive outbursts on 9P/Tempel 1

The shape, topography, and geology of Tempel 1 from Deep Impact observations

Deep Impact images of the nucleus of Comet Tempel 1 reveal pervasive layering, possible impact craters, flows with smooth upper surfaces, and erosional stripping of material. There are at least 3 layers 50–200 m thick that appear to extend deep into the nucleus, and several layers 1–20 m thick that parallel the surface and are being eroded laterally. Circular depressions show geographical varia...

The Composition of Dust in Jupiter-Family Comets Inferred From Infrared Spectroscopy

We review the composition of Jupiter-family comet dust as inferred from infrared spectroscopy. We find that Jupiter-family comets have 10 μm silicate emission features with fluxes roughly 20–25% over the dust continuum (emission strength 1.20–1.25), similar to the weakest silicate features in Oort Cloud comets. We discuss the grain properties that change the silicate emission feature strength (...

Comet 9p/tempel 1: Interpretation with the Deep Impact Results

According to our common understandings, the original surface of a shortperiod comet nucleus has been lost by sublimation processes during its close approaches to the Sun. Sublimation results in the formation of a dust mantle on the retreated surface and in chemical differentiation of ices over tens or hundreds of meters below the mantle. In the course of NASA’s Deep Impact mission, optical and ...

Deep Impact: excavating comet Tempel 1.

Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (<65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (>1000 kelvins). A large increase in organic materi...