The Cassini Imaging Science Subsystem (ISS) is the highest-resolution two-dimensional imaging device on the Cassini Orbiter and has been designed for investigations of the bodies and phenomena found within the Saturnian planetary system. It consists of two framing cameras: a narrow angle, reflecting telescope with a 2-m focal length and a square field of view (FOV) 0.35 • across, and a wide-angle refractor with a 0.2-m focal length and a FOV 3.5 • across. At the heart of each camera is a charged coupled device (CCD) detector consisting of a 1024 square array of pixels, each 12 µ on a side. The data system allows many options for data collection, including choices for on-chip summing, rapid imaging and data compression. Each camera is outfitted with a large number of spectral filters which, taken together, span the electromagnetic spectrum from 200 to 1100 nm. These were chosen to address a multitude of Saturn-system scientific objectives: sounding the three-dimensional cloud structure and meteorology of the Saturn and Titan atmospheres, capturing lightning on both bodies, imaging the surfaces of Saturn's many icy satellites, determining the structure of its enormous ring system, searching for previously undiscovered Saturnian moons (within and exterior to the rings), peering through the hazy Titan atmosphere to its yet-unexplored surface, and in general searching for temporal variability throughout the system on a variety of time scales. The ISS is also the optical navigation instrument for the Cassini mission. We describe here the capabilities and characteristics of the Cassini ISS, determined from both ground calibration data and in-flight data taken during cruise, and the Saturn-system investigations that will be conducted with it. At the time of writing, Cassini is approaching Saturn and the images returned to Earth thus far are both breathtaking and promising. r forty-five (45) close 'targeted' flybys of Titan (40 of which approach within 2500 km of the surface, and 24 of these within 1000 km of the surface); r very close 'targeted' flybys of Enceladus (4) (Figure 3), Dione, Rhea, Iapetus, and Hyperion, all approaching within ∼1500 km of the surface; r thirty-one (31) non-targeted but still close (within 100,000 km of the surface) flybys of Iapetus and the five major icy satellites Mimas, Enceladus, Tethys, Dione and Rhea;

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EDTA has become a major organic pollutant in the environment because of its extreme usage and resistance to biodegradation. Recently, two critical enzymes, EDTA monooxygenase (EmoA) and NADH:FMN oxidoreductase (EmoB), belonging to the newly established two-component flavin-diffusible monooxygenase family, were identified in the EDTA degradation pathway in Mesorhizobium sp. BNC1. EmoA is an FMNH 2 -dependent enzyme that requires EmoB to provide FMNH 2 for the conversion of EDTA to ethylenediaminediacetate. To understand the molecular basis of this FMN-mediated reaction, the crystal structures of the apo-form, FMN⅐FMN complex, and FMN⅐NADH complex of EmoB were determined at 2.5 Å resolution. The structure of EmoB is a homotetramer consisting of four ␣/␤-single-domain monomers of five parallel ␤-strands flanked by five ␣-helices, which is quite different from those of other known two-component flavin-diffusible monooxygenase family members, such as PheA2 and HpaC, in terms of both tertiary and quaternary structures. For the first time, the crystal structures of both the FMN⅐FMN and FMN⅐NADH complexes of an NADH:FMN oxidoreductase were determined. Two stacked isoalloxazine rings and nicotinamide/isoalloxazine rings were at a proper distance for hydride transfer. The structures indicated a ping-pong reaction mechanism, which was confirmed by activity assays. Thus, the structural data offer detailed mechanistic information for hydride transfer between NADH to an enzyme-bound FMN and between the bound FMNH 2 and a diffusible FMN.EDTA has quietly become a major organic pollutant, currently present in the environment at higher concentrations than any other organic pollutant (1). A high level of EDTA in natural waters is due to its extensive usage, such as in industrial cleaning to remove calcium deposits, in detergent as a sequestering agent, in phytoremediation to mobilize heavy metals, and in scientific laboratories as a chelating agent (2, 3). EDTA is recalcitrant to biodegradation and exists mainly in metal⅐EDTA complexes, many of which are toxic (4, 5). In addition, the codisposal of EDTA with radionuclides has led to the enhanced mobilization of radionuclides in groundwater, rapidly spreading radioactive contamination (3, 6 -8). Concerns over EDTA recalcitrance and the potential mobilization of heavy metals and radionuclides have led the European Union, Australia, and some parts of the United States to ban EDTA in detergent. It is now also being carefully controlled in many other products to reduce contamination of water resources.Several bacteria that can degrade EDTA and the related compound, nitrilotriacetate, and use them as a sole source of carbon and energy have been isolated (9 -12). They are phylogenetically related to Mesorhizobium and Agrobacterium species (11), likely forming a new branch within the Phyllobacteriaceae, the "Mesorhizobia" family (13). In these bacteria, reduced flavin mononucleotide (FMNH 2 )-dependent EDTA monooxygenase (EmoA) and NADH:FMN oxidoreductase (EmoB) together oxidize EDTA to e...

We find that Jupiter is significantly darker at partial phases than an idealized Lambertian planet by roughly 25% and is not well fit by Jupiter-like exoplanet atmospheric models across all wavelengths. We provide analytic fits to Jupiter's phase function in several Cassini/ISS imaging filter bandpasses. In addition, these observations show that Jupiter's color is more variable with phase angle than predicted by models. Therefore, the color of even a near Jupiter-twin planet observed at a partial phase cannot be assumed to be comparable to that of Jupiter at full phase. We discuss how WFIRST and other future direct-imaging missions can enhance the study of cool giants.