Word: jacchia
(lookup in dictionary)
(lookup stats)
Dates: during 1950-1959
Sort By: most recent first
(reverse)
...latter eventuality, added almost as an afterthought, turned out to be the critical factor. During the summer it was determined in that spherical satellites also behaved in the same peculiar fashion as the cylindrical satellites. By late September Jacchia had discovered some periodicity in the acceleration of Sputnik II and ruled out change in presentation area of the satellite as a factor. He wrote...
...first Jacchia sought some connection between solar flares and the acceleration of the satellites. When the flares proved too erratic he turned to geomagnetic data. Again the correlation was poor...
...break-through came when Dr. Priester of the Bonn Observatory called Jacchia's attention to the connection between solar radio wave data and the satellites' acceration. The very first hint Jacchia saw was that two peaks in an otherwise calm period occurred at the same time on both the satellite graph and the graph of 20 cm. solar radiation. With observations of 10.7 cm radiation transmitted daily from the National Research Council at Ottawa, Canada, he took a longer look, and found the amazing correspondence between solar emission and satellite acceleration reproduced above. This one-for-one relationship...
Unlike many of the IGY projects, the satellite program continued after the end of the Geophysical Year, and grows more complicated daily. It is only now that studies such as Jacchia's are being implemented...
...small number of mathematicians and upper-atmosphere specialists at Smithsonian, many of whom also lecture at the University. Fred L. Whipple, Director of the Smithsonian Observatory, is an expert on meteors and meteoric risk to satellites as well as optical tracking; Theodore E. Sterne, Associate5The basis of JACCHIA'S discovery of the direct relationship between solar radiation and the movement of the satellites is illustrated by these four lines. The top two plots show the acceleration of two earth satellites due to varying atmospheric density, over a period from April to December, 1958. The third graph is the intensity...