ALBERT

Beschreibung: Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices. Neptune's atmosphere is dominated by a large anticyclonic storm system that has been named the Great Dark Spot (GDS). About the same size as Earth in extent, the GDS bears both many similarities and some differences to the Great Red Spot of Jupiter. Neptune's zonal wind profile is remarkably similar to that of Uranus. Neptune has three major rings at radii of 42,000, 53,000, and 63,000 kilometers. The outer ring contains three higher density arc-like segments that were apparently responsible for most of the ground-based occultation events observed during the current decade. Like the rings of Uranus, the Neptune rings are composed of very dark material; unlike that of Uranus, the Neptune system is very dusty. Six new regular satellites were found, with dark surfaces and radii ranging from 200 to 25 kilometers. All lie inside the orbit of Triton and the inner four are located within the ring system. Triton is seen to be a differentiated body, with a radius of 1350 kilometers and a density of 2.1 grams per cubic centimeter; it exhibits clear evidence of early episodes of surface melting. A now rigid crust of what is probably water ice is overlain with a brilliant coating of nitrogen frost, slightly darkened and reddened with organic polymer material. Streaks of organic polymer suggest seasonal winds strong enough to move particles of micrometer size or larger, once they become airborne. At least two active plumes were seen, carrying dark material 8 kilometers above the surface before being transported downstream by high level winds. The plumes may be driven by solar heating and the subsequent violent vaporization of subsurface nitrogen.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, B A -- Soderblom, L A -- Banfield, D -- Barnet, C -- Basilevsky, A T -- Beebe, R F -- Bollinger, K -- Boyce, J M -- Brahic, A -- Briggs, G A -- Brown, R H -- Chyba, C -- Collins, S A -- Colvin, T -- Cook, A F 2nd -- Crisp, D -- Croft, S K -- Cruikshank, D -- Cuzzi, J N -- Danielson, G E -- Davies, M E -- De Jong, E -- Dones, L -- Godfrey, D -- Goguen, J -- Grenier, I -- Haemmerle, V R -- Hammel, H -- Hansen, C J -- Helfenstein, C P -- Howell, C -- Hunt, G E -- Ingersoll, A P -- Johnson, T V -- Kargel, J -- Kirk, R -- Kuehn, D I -- Limaye, S -- Masursky, H -- McEwen, A -- Morrison, D -- Owen, T -- Owen, W -- Pollack, J B -- Porco, C C -- Rages, K -- Rogers, P -- Rudy, D -- Sagan, C -- Schwartz, J -- Shoemaker, E M -- Showalter, M -- Sicardy, B -- Simonelli, D -- Spencer, J -- Sromovsky, L A -- Stoker, C -- Strom, R G -- Suomi, V E -- Synott, S P -- Terrile, R J -- Thomas, P -- Thompson, W R -- Verbiscer, A -- Veverka, J -- New York, N.Y. -- Science. 1989 Dec 15;246(4936):1422-49.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17755997" target="_blank"〉PubMed〈/a〉

Beschreibung: Directional ocean wave spectra derived from Shuttle Imaging Radar-B (SIR-B) L-band imagery collected off the coast of southern Chile on 11 and 12 October 1984 were compared with independent spectral estimates from two airborne scanning radars. In sea states with significant wave heights ranging from 3 to 5 meters, the SIR-B-derived spectra at 18 degrees and 25 degrees off nadir yielded reasonable estimates of wavelengths, directions, and spectral shapes for all wave systems encountered, including a purely azimuth-traveling system. A SIR-B image intensity variance spectrum containing predominantly range-traveling waves closely resembles an independent aircraft estimate of the slope variance spectrum. The prediction of a U.S. Navy global spectral ocean wave model on 11 October 1984 exhibited no significant bias in dominant wave number but contained a directional bias of about 30 degrees espect to the mean of the aircraft and spacecraft estimates.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Beal, R C -- Monaldo, F M -- Tilley, D G -- Irvine, D E -- Walsh, E J -- Jackson, F C -- Hancock, D W 3rd -- Hines, D E -- Swift, R N -- Gonzalez, F L -- Lyzenga, D R -- Zambresky, L F -- New York, N.Y. -- Science. 1986 Jun 20;232(4757):1531-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17773503" target="_blank"〉PubMed〈/a〉