Solid organics in cometary comae

Dynamic molecular oxygen production in cometary comae

Abundant molecular oxygen was discovered in the coma of comet 67P/Churyumov-Gerasimenko. Its origin was ascribed to primordial gaseous O2 incorporated into the nucleus during the comet's formation. This thesis was put forward after discounting several O2 production mechanisms in comets, including photolysis and radiolysis of water, solar wind-surface interactions and gas-phase collisions. Here ...

Origin and production of C(1D) atoms in cometary comae

The abundance of carbon atoms in the metastable 1D state near the cometary nucleus provides an important diagnostic of one of the principal sources of carbon in the cometary coma. This quantity may be determined in two independent ways: measurement of 1D–1P fluorescence at 1931 Å and by prompt emission of the 1D–3P doublet at 9823/9850 Å. The latter is analogous to the [O i] λλ6300/6364 emissio...

Anaerobic Digestion of Biodegradable Organics in Municipal Solid Wastes

Atomic Oxygen in the Comae of Comets

We report on the detection of atomic oxygen lines in the spectra of 8 comets. These forbidden lines are a result of the photodissociation of the parent oxygen-bearing species directly into an excited state. We used high resolution spectra obtained at the McDonald Observatory 2.7m telescope to resolve the cometary oxygen lines from the telluric oxygen lines and from other cometary emissions. We ...

Subcritical-Water Extraction of Organics From Solid Matrices

An apparatus for extracting organic compounds from soils, sands, and other solid matrix materials utilizes water at subcritical temperature and pressure as a solvent. The apparatus, called subcritical water extractor (SCWE), is a prototype of subsystems of future instrumentation systems to be used in searching for organic compounds as signs of past or present life on Mars. An aqueous solution g...