For 150 years scientists have tried

For 150 years scientists have tried to determine the solar constant, the amount of solar energy that reaches the Earth. Yet, even in the most cloud-free regions of the planet, the solar constant cannot be measured precisely. Gas molecules and dust particles in the atmosphere absorb and scatter sunlight and prevent some wavelengths of the light from ever reaching the ground.


With the advent of satellites, however, scientists have finally been able to measure the Sun's output without being impeded by the Earth's atmosphere. Solar Max, a satellite from the National Aeronautics and Space Administration (NASA), has been measuring the Sun's output since February 1980. Although a malfunction in the satellite's control system limited its observation for a few years, the satellite was repaired in orbit by astronauts from the space shuttle in 1984. Max's observations indicate that the solar constant is not really constant after all.

The satellite's instruments have detected frequent, small variations in the Sun's energy output, generally amounting to no more than 0.05 percent of the Sun's mean energy output and lasting from a few days to a few weeks. Scientists believe these fluctuations coincide with the appearance and disappearance of large groups of sunspots on the Sun's disk. Sunspots are relatively dark regions on the Sun's surface that have strong magnetic fields and a temperature about 2,000 degrees Fahrenheit cooler than the rest of the Sun's surface. Particularly large fluctuations in the solar constant have coincided with sightings of large sunspot groups. In 1980, for example, Solar Max's instruments registered a 0.3 percent drop in the solar energy reaching the Earth. At that time a sunspot group covered about 0.6 percent of the solar disk, an area 20 times larger than the Earth's surface.

Long-term variations in the solar constant are more difficult to determine. Although Solar Max's data have indicated a slow and steady decline in the Sun's output, some scientists have thought that the satellite's aging detectors might have become less sensitive over the years, thus falsely indicating a drop in the solar constant. This possibility was dismissed, however, by comparing Solar Max's observations with data from a similar instrument operating on NASA's Nimbus 7 weather satellite since 1978.

Kết quả (Anh) 1:

For 150 years the scientists tried to identify the solar constant, solar energy reaches the Earth. However, even in these regions for free cloud of the planet, the solar constant may not be correctly identified. The gas molecules and dust particles in the atmosphere absorb and diffuse the sunlight and prevent certain wavelengths of light from ever reaching the ground. With the advent of the satellite, however, scientists were finally able to measure the output of the Sun without being hindered by the Earth's atmosphere. Solar Max, a satellite from the aviation and Space Agency (NASA), has been measuring the Sun's output since February 1980. Although a breakdown in the control system of the satellites only limited observations of it for a few years, the satellite has to be repaired in orbit by astronauts from the space shuttle in 1984. Max's observations indicate that the solar constant is not really continuously after all. the satellite's instruments have been frequent, small changes in the energy output of the Sun, often occupy not more than 0.05 per cent of the average energy output of the Sun and lasts from several days to several weeks. Scientists believe that these fluctuations coincided with the appearance and disappearance of the large group of sunspots on the Sun's disk. Sunspots are relatively dark areas on the Sun's surface has a strong magnetic field and temperatures of about 2,000 degrees Fahrenheit cooler than the rest of the surface of the Sun. Special large fluctuations in the solar constant has coincided with signs of a large sunspot group. In the 1980s, for example, tools for Solar Max have registered rising 0.3 percent in solar energy reaching the Earth. At that point, a sunspot group that covered about 0.6 percent of the solar disk, the bigger the surface area of the Earth 20 times. long-term variations in solar constants are more difficult to identify. Although the data of Solar Max have shown a slow and steady decline of output of the Sun, some scientists have thought that aging satellite's detectors may have become less sensitive over the years, so it's wrong to point out a drop of water in the solar constant. This possibility has been rejected, however, by comparing the observed Solar Max with the data from a similar instrument works with Nimbus 7 weather satellite of NASA since 1978.

Kết quả (Anh) 2:

For 150 years scientists have tried to determine the solar constant, solar energy reaches the Earth. However, even in areas free cloud most of the planet, solar constant heaven can not be determined exactly. The gas molecules and dust particles in the atmosphere absorb and scatter sunlight and prevent certain wavelengths of light from ever reaching the ground. With the the advent of satellites, however, scientists can finally measure the output of the sun without being hindered by the Earth's atmosphere. Solar Max, a satellite from Space Agency and not National Space Administration (NASA), has been measuring the output of the Sun since February 1980. Although a malfunction in the control system of satellites is limited to its observation for a few years, satellites have repaired in orbit by astronauts from the space shuttle in 1984. Max's observations indicate that the solar constant is not really constant after all. of satellite instruments have been discovered frequent, small changes in the energy output of the sun, often with less than 0.05 percent of the average energy output of the Sun and lasts from a few days to a few weeks. The scientists believe that these changes coincided with the appearance and disappearance of large groups of sunspots on the sun's disk. Vet literally relatively dark areas on the surface of the Sun has a strong magnetic field and temperature about 2000 degrees Fahrenheit cooler than the rest of the solar surface. Movements in particularly large in the solar constant has coincided with signs of large sunspot groups. In 1980, for example, instruments Solar Max had registered a fall of 0.3 percent in solar energy reaches the Earth. At that time, a group of sunspots cover about 0.6 percent of the solar disk, with larger surface area 20 times the Earth's surface. Long-term variations in the solar constant is much more difficult to determine. Although data of Solar Max has shown a slow and steady decline in output of the Sun, some scientists think detector aging satellites may have become less sensitive over the years, so wrong just a drop in the solar constant. Ability This was rejected, however, by comparing the observed Solar Max with data from a similar device operating on the Nimbus 7 satellite NASA's weather since 1978.