Cassini

Two important substances have so far not been found on Titan the noble gas argon and water. The analysis of the results of the successful Cassini mission may soon shed light on this mystery. 

The most recent results from the successful Cassini-Huygens mission will be discussed in Sect. 11.1.1.3. 

These new results only became possible when the groups of H. Waite and B. Magee at the South West Research Institute (SWRI) in San Antonio, Texas, combined analytical data obtained from two different instruments. These are the ion and neutral mass spectrometer (INMS), which obtained data on small to medium-sized molecules in the upper atmosphere of Titan (950-1,150 km) and the Cassini plasma spectrometer (CAPS), which also registered particles from tholins, both positive (100-350 Da) and negative ions (20-8,000 Da) (Waite et al., 2007 Atrey, 2007). 

Important weather details are not only provided by the newest information from the Cassini orbiter the Very Large Telescope in the Atacama desert and the W. M. Keck Observatory on Hawaii are also involved. Near-IR spectra show increased cloudiness in the Titanian troposphere on the morning side, i.e., there are methane clouds at a height of about 30 km and methane drizzle at the surface (Adamkovics et al., 2007). 

Figure 10.1 This image taken by the Cassini probe is in the infrared centred at 980 nm (Image scale is 7 kilometers per pixel) and shows features on the leading hemisphere of Titan, including the bright, crescent-shaped Hotei arcus (right of center), which is also informally called "the Smile" by researchers. (Reproduced by permission of NASA/JPL/Space Science Institute)...

Finally, and tantalizingly for this book and astrochemistry, there is Titan. The Cassini-Huygens mission is now in orbit in the Saturnian system as the book is published. The Huygens probe has already made the descent to the surface of Titan and the data have been transmitted back successfully. Scientists, astronomers, astrochemists and astribiologists are trying to understand it. I have taken a brief look at Titan as a case study to apply all that has been learnt and to review the possibilities for astrochemistry in what is surely to be a very exciting revelation of the structure and chemistry of Titan. 

Contours of constant signal to noise ratio follow the lines of ovals of Cassini as the signal to noise ratio is inversely proportional to the product of the squares of the transmitter to target and target to receiver ranges. In monostatic radar contours of constant signal to noise ratio are circles. 

The bi-static theoretical coverage diagram forms the so-called Cassini curve, presented in Figure 7. In practice it is not possible to detect targets in the direction of the transmitter line-of-sight, and practical bi-static radar coverage is presented in Figure 8. 

Encyclopedic Methodique. Physique Monge, Cassini, Bertholon et al., 1822... 

When A. S. Marggraf tried to prepare alum from alumina and vitriolic acid, he found that unless he added fixed alkali he obtained no crystals (19). In 1777 Lavoisier clearly stated that potash is an essential constituent of alum (18, 20). In analyzing a water containing aluminum sulfate, which the younger Cassini had sent him from Italy, Lavoisier added some potash When he evaporated the solution, he obtained crystals of alum and realized that this was a verification of the results of Marggraf and of Macquer. 

The space mission Cassini, destined to explore the neighborhood of Saturn, will accumulate a large mass of scientihc data. This mission was extremely costly. With the same money, hundreds of hospitals and schools in Africa could have been built. Where would you have invested that amount of money ... 

Some of the elements of war have found a place in peacetime. The same kind of reaction in uranium that makes an atomic bomb explode can be controlled to make electricity in a nuclear power plant. The Cassini spacecraft now orbiting the planet Saturn runs on plutonium fuel. Plutonium-based fuel was also used to power devices that the Apollo 14 astronauts left on the Moon, such as a seismometer left to detect movements of the Moons crust. The Voyager spacecraft also sent its golden record out to the stars with... 

Kaiser, P, J. Pochon, and R. Cassini (1970). Effect of triazine herbicides on soil microorganisms. In F.A. Gunther and J.D. Gunter, eds., The Triazine Herbicides. Residue Rev., 32 New York Springer-Verlag, pp. 211-233. 

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