摘要:

Voyager 1 Voyager 2 Spacecraft distance from Earth (km) 1,403,792,373 1,196,379,829 Spacecraft distance to Saturn (km) 132,531,596 365,583,009 Spacecraft distance traveled since launch (km) 1,994,859,408 1,745,872,032 Spacecraft velocity relative to Earth (km/s) 49.8 46.6 Spacecraft velocity relative to sun (km/s) 20.5 17.2 Date of Saturn encounter (closest approach) Nov. 12,1980 Aug. 27, 1981

ISSN:0002-8606    

DOI:10.1029/EO061i035p00593-01

年代:1980

数据来源: WILEY

摘要:

Coal will be the leading source of energy in the United States by the year 2000, and it will be consumed primarily in the form of liquids and gases. Edward A. Frieman, director of energy research for the U.S. Department of Energy (DOE) offered these projections in a recent briefing to representatives of U.S. scientific and engineering societies.Renewable forms of energy (solar, biomass, and hydroelectric) are expected to reach only half of the 20% share projected in recent years.

ISSN:0002-8606    

DOI:10.1029/EO061i035p00594-03

年代:1980

数据来源: WILEY

摘要:

Using a new type of measuring device flown in space for the first time, a National Aeronautics and Space Administration (NASA) satellite has detected small changes—over periods of days to months—in the brightness of the sun.Detection of even the slightest change in the amount of light and heat energy emitted by the sun is important because if a trend were to continue for several years, it could produce major alterations in the earth's climate. Measurement of such trends might enable scientists to predict future climate chan

ISSN:0002-8606    

DOI:10.1029/EO061i035p00595

年代:1980

数据来源: WILEY

摘要:

The use of spacecraft to take the first close look at comets and to begin to explore their characteristics is a high‐priority goal for space science and should be attempted in this decade, according to a report by a blue ribbon National Research Council committee. Similar investigation of asteroids should be made during the next decade and a half, said the committee.The report also suggests that collection of interplanetary dust and intensive study of meteoroids are vital parts of solar system researc

ISSN:0002-8606    

DOI:10.1029/EO061i035p00596

年代:1980

数据来源: WILEY

摘要:

Mount St. Helens Volcano, Cascade Range, Southern Washington, U.S.A. (46.20°N, 122.18°W). All times are local (GMT − 7 h). Richard Janda of the U.S. Geological Survey calculated that about 2 km3of debris was emplaced in the north fork of the Toutle River and Spirit Lake by the May 18 eruption. Richard Waitt, also of the USGS, estimated the total May 18 airfall component as 1.1 km3of unconsolidated material, having a mean bulk density of 0.5 g/cm3. Poor weather has prevented the aerial photography necessary for the production of a topographic map of the post‐May 18 volcano. After a map is produced, the amount of material removed from the edifice on May 18 can be accurately deter

ISSN:0002-8606    

DOI:10.1029/EO061i035p00597

年代:1980

数据来源: WILEY