Exploration of the moon and planets

Unmanned interplanetary flight - engineering problems of mariner ii space prob

Some new methods for planetary exploration

For many centuries the planets of our solar system have been objects of study by astronomers. Before the invention of the telescope, these studies were restricted to an attempt to understand and predict their motion. Telescopes and accurate clocks allowed more precise observations to be made. By the 19th century, minor perturbations of the motions of the planets were being analyzed. By the end of this century, however, astronomers were becoming more interested in stellar and galactic problems, and the group interested in celestial mechanics and planetary observations appeared to be decreasing to a vanishing point in the mid-20th century. Then came the space program, and the possibility of performing experiments on, or at least near, other planets encouraged interest in the solar system to a remarkable degree

Pioneer III News Release

No abstract availabl

A three-year follow-up survey of demographic changes in a Ugandan town on the trans-African highway with high HIV-1 seroprevalence

A 1991 serosurvey in a Ugandan trading town on the trans-African highway reported a 40 per cent HIV-1 prevalence in adults. Three years later in a repeat survey of the 531 adults resident in 1991, 279 (53%) were still present, 196 (37%) had left and 56 (11%) had died. There were 138 new residents and 46 children had become adults, making a total of 463 adults in 1994, 13 per cent less than 1991. Most immigrants (91%) came from the surrounding rural district whereas 38 per cent of emigrants went to an urban area. A significant inverse association between wealth and seropositivity was found for women but not men. Of the original residents 157 were known to be HIV-1 positive in 1991; 31 (20%) had died compared to 10 (4%) of the 232 known to be seronegative, representing an HIV-1 attributable mortality fraction of 60 per cent

The Radio Sonde

The radio sonde has been developed in recent years as a practical instrument for transmitting information from the stratosphere. This paper discusses some of the problems connected with the application of the radio-sonde principle to the radio meteorograph and also to the cosmic-ray radio sonde

Results of a High Altitude Cosmic-Ray Survey Near the Magnetic Equator

Electroscope and Geiger counter observations have been taken with free balloons at geomagnetic latitudes of 3°, 17°, and 25°N. The most important results are as follows: (1) The Geiger counter technique with a single counter will give results very close to those obtained with the electroscope and of comparable accuracy. (2) Vertical coincidence measurements give rise to markedly different values for the relative amounts of incident energy at various latitudes, as compared with the electroscope or single counter data. (3) Within the experimental error, no difference was obtained between the vertical coincidence curves at 3° and 17°, and thus no new energy lies in the primary energy spectrum between the limits of 17 and 15 Bev. (4) This is direct evidence for a banded structure in the primary cosmic-ray spectrum. (5) Flights made with triple and quadruple coincidences, and also with counters arranged to record showers, showed that showers do not significantly affect the vertical coincidence measurements