摘要:

The National Aeronautics and Space Administration has assigned to the Jet Propulsion Laboratory the responsibility for design and development of spacecraft for the exploration of the moon, the planets, and interplanetary space. In carrying out its assignment, JPL, the United States' oldest guided‐missile and rocket‐research laboratory, is designing and fabricating spacecraft to be flown past the moon and to land scientific equipment on the surface of the moon. Designs have also begun for spacecraft to fly past the planets and land capsules of scientific instruments on the planetary surfaces. This paper describes the Ranger spacecraft, now undergoing assembly, which will initiate the lunar exploration program; the Mariner, now being designed, which will initiate the planetary program with a flight past Venus; and the Surveyor, in which packages of scientific instruments will be soft‐landed on the

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02003

年代:1961

数据来源: WILEY

摘要:

A scintillation counter responding principally to direct electrons has been flown on the Explorer VI earth satellite in an elliptical orbit extending to 48,600 km. The instrument measured fluxes of electrons above 200 kev and protons above 2 Mev. After a week of magnetically quiet observations, a geomagnetic storm occurred, and an immediate increase in the counting rate of this instrument was detected; other radiation instruments showed a decrease in counting rate at this time. Gross fluctuations in particle intensity were observed at the edge of the outer zone of the Van Allen radiation belt during the storm, and these fluctuations are closely related to simultaneous geomagnetic activity. The increased particle intensity in the outer zone declined quite slowly after the storm until the next period of magnetic activity about two weeks later. This paper presents a detailed summary of the observations made by the scintillation counter during the period of data reception from the satellite.

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02013

年代:1961

数据来源: WILEY

摘要:

An attempt has been made to detect and measure any vertically incident flux of low‐energy (0.25 to 10 Mev) gamma rays that might be present at high altitudes. The experiment consisted of a series of balloon flights carrying a phoswitch gamma spectrometer with pulse height ecording to altitudes of about 5.5 g/cm2atmosphere depth. Directional sensitivity was obtained by placing a lead collimating shield around the detector and by periodically opening and closing a lead shutter above the opening of the shield. At altitudes between 5.4 and 6.0 g/cm2atmospheric depth the experiment yielded a value of 0.000±0.034 photons sec−1cm−2sterad−1for the vertical flux of gamma rays in the vicinity of 0.5 Mev energy. This is a null result; however, it places a new upper limit on the vertical gamma‐ray flux that is lower than any previously reported for this energy region. At lower altitudes it was observed that gamma rays are generated by cosmic rays in the atmosphere and in the collimating lead shield. At an atmospheric depth of 300 g/cm2the flux of gamma rays from the atmosphere was about 0.3 photons sec−1cm−2sterad−1. Convincing evidence was found that the gamma rays of atmospheric origin were generated by the secondary nucleonic component, and that they are not genetically related to the electromagnetic or ‘soft’ component of the s

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02029

年代:1961

数据来源: WILEY

摘要:

During a period of intense solar activity between March 26 and April 6, 1960, measurements of the magnetic fields in interplanetary space were obtained with the space probe, Pioneer V. The measured component of the fields, associated with the solar plasma ejected during this period, attained strengths of 40 or more gammas (compared to an average value of 2.7 gammas during normal periods). It is argued that these comparatively high fields existed in interplanetary space for many hours. From estimates of the plasma velocity, the radial extent of these regions of high field is calculated to be 0.7 AU. The fields associated with these regions were observed to be quite regular. Similar results accompanied most of the more intense solar activity during the flight of Pioneer V. Possible implications of these results are discussed.

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02043

年代:1961

数据来源: WILEY

摘要:

A Fokker‐Planck equation for the distribution function of electrons trapped in a magnetic field in the presence of a scattering atmosphere is applied to the Van Allen electron belt. Solutions are obtained for the equilibrium flux resulting from an electron source of arbitrary energy for the cases where (a) loss of energy by collisions is neglected, and (b) loss by diffusion out of the trapping region is neglected; and an approximate solution is obtained for the actual case where both processes are important. The assumption that the electron source is supplied by decaying neutrons leads to an equilibrium electron flux whose energy dependence is qualitatively different from the observed spectru

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02047

年代:1961

数据来源: WILEY

摘要:

During a severe magnetic storm, observatory records obtained in high latitudes may show a type of disturbance here called a ‘cusped bay,’ characterized by a marked displacement of the trace, coupled with augmented short‐period fluctuations. Several of these events registered during the IGY at stations near the northern and southern auroral zones, some with amplitudes approaching 2000 γ, were measured on all appropriate magnetograms and plotted on maps as equivalent overhead current vectors. They show some of the characteristics of systems based on hourly‐value changes during storms. However, they afford almost no evidence of the afternoon eastward segment of the auroral electrojet, and the polar‐cap effects are indicative of patterns having greater complexity than the one usually ascribed to this region. The author recommends the study of cusped bays as a supplement to the use of hourly values and a means of probing details of magnetic activity that are difficult to approach in other ways. A catalog of IGY storms is appended to the paper. This article contains supplementar

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02053

年代:1961

数据来源: WILEY

摘要:

Oscillations of the geomagnetic field with periods between 1 second and a few minutes have been studied by means of large ground loops at Hobart, Adelaide, Camden, and Townsville, Australia. Records have been made both on charts and on slowly moving magnetic tape; the tape recordings have been analyzed for frequency components on a ‘Sonagraph’ sound spectroscope.The period of the continuous oscillations known asPC's shows a diurnal variation and a marked ependence on latitude, shorter periods occurring at lower latitudes.The damped trains of oscillations, occurring predominantly around local midnight, known asPt's are followed by magnetic bays with an average delay of about 15 minutes.During storms, ‘sweepers’—oscillations with a progressive change of frequency and sometimes with aharmonic overtones—a

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02087

年代:1961

数据来源: WILEY

摘要:

An Aerobee rocket flown from White Sands Missile Range at 1115 UT, November 29, 1960, included a first experimental attempt to measure the intensity of the helium glow in the night sky. The experiment has provided evidence that the brightness of this glow is less than one tenth the brightness of the night Lyman α glow. The photoelectric detector produced signals that may be interpreted as evidence that a supply of metastable molecules exists in the night ionosphere at altitudes above 100 km

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02095

年代:1961

数据来源: WILEY

摘要:

Simultaneous observations of an auroral arc from Cactus Peak, California, and Fritz Peak, Colorado, on the night of April 1–2, 1960, have provided the information necessary to determine the height of maximum luminosity and the geographical position of the arc. Twenty pairs of measurements determine the average height to be 425 km with a standard deviation of ±22 km from the average for a single pair of observations. The arc, observed from a point over the Pacific Ocean off the Oregon Coast to a point over the state of Mississippi, lay generally along a line of equal magnetic inclinati

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02101

年代:1961

数据来源: WILEY

摘要:

Observations of the Australian National Antarctic Research Expedition at Wilkes in 1959 indicate two features of auroral behavior similar to that observed at other stations on the poleward side of the isoaurore of maximum frequency: (1) diurnal variation of overhead occurrence exhibits evening and morning maxima, and (2) homogeneous auroras tend to be aligned in the sun‐earth line. The observations do not indicate the existence of an inner auroral zone within the field of view of Wilkes station. Directions of transverse movement of auroras tend to be westward, but velocities are not accounted for by a simple orientation‐fixed mo

ISSN:0148-0227    

DOI:10.1029/JZ066i007p02105

年代:1961

数据来源: WILEY