13. Una Crociera Movimentata I fly-bys con la Terra e Venere hanno fornito l’equivalente di 75 tonnellate di carburante (Al lancio i serbatoi di Cassini ne contenevano 3 tonnellate)
25. Saturn is less brightly banded than Jupiter: Same 3 layers, but atmosphere is thicker, so we don’t see different colored layers as well. This is due to Saturn’s lower surface gravity
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28. Le immagini mostrate in bianco e nero sono state riprese dalla fotocamera di Cassini mentre le due in blu e rosso sono dello strumento VIMS. Il Polo stesso è proprio nell’occhio di questo immenso vortice polare delle dimensioni di circa 1500km. Il Polo Sud di Saturno 460nm 752nm 728nm 890nm 5000nm 2800nm CH 4 CH 4
35. Rings and the “Roche Limit” Inside the Roche limit, the tidal stresses on a body (which grow with its size and closeness) are stronger than its internal strength (basically gravity, in the case of moons). This is generally at 2.5 planetary radii or so.
36. Composition of Saturn’s Rings Rings are composed of ice particles moving at large velocities around Saturn, but small relative velocities (all moving in the same direction). 0
45. The “Opposition Surge” on Saturn’s rings. This appears exactly opposite to the direction to the Sun, at phase angle 0°. The size of the surge is a measure of how rough the particles are.
52. Febe è il satellite più lontano e si trova su di una orbita retrograda ad una distanza di 13 milioni di km da Saturno; La densità, l’aspetto e le dimensioni di Febe sono caratteristiche dei cosiddetti planetesimi, frammenti di materiale primordiale andato poi ad accumularsi a formare i pianeti. Simili residui del processo di accrescimento potrebbero essere sopravvissuti nelle zone più esterne del sistema solare, ma non nelle vicinanze di Saturno. Febe: un alieno alla corte di Saturno? 0.3 Km/px 2.1 Km/px
63. … and VIMS Ratio of 1.2 µm continuum over 1.6 µm cristalline water ice band Cristalline ice is concentrated inside the tiger stripes Consistent with higher emission temperatures
67. Titan Facts Titan belongs to the triad of giant moons with bulk densities of 1.8 g/cm3, and radii ~ 2500 km, along with Ganymede and Callisto. Titan has the second-densest atmosphere of the solid bodies of the solar system Surface P,T=1.5bars, 95K. Methane 2-10% near-surface, 2% in stratosphere. Nitrogen-methane atmospheric composition implies organic chemistry.
68. Methane Cycle The photolysis of methane and nitrogen leads to the formation of complex hydrocarbons, polycyclic aromatic hydrocarbon (PAH), nitriles and polymers; The resulting compounds lead to the production of haze (Tholins), of hydrocarbons condensates and their precipitation on ground. Methane is also key to the maintenance of the thick nitrogen atmosphere. The nitrogen atmosphere would gradually condense in the absence of warming resulting from the hydrocarbon haze Methane is lost in the atmosphere with a lifetime of 10-100 Myr Waite et al, 2007 700km
80. IAPETUS - ORSHIRES001-V1568145604 Distance 45600 km - Phase 32° - VIMS 22.8 Km/pixel VIMS-IR @ R 2.42 um (CN); G 2.05 um (H2O), B 1.94 um (OH) ISS-WAC (raw data) VIMS-V @ 970 nm