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 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 closing virtually 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) 2:

For 150 years have tried to quyết scientists of the solar constant, the amount of solar energy the Earth Reaches mà. Yet, even level in the nhất cloud-free Regions of the planet, the solar constant can not 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, Tuy nhiên, scientists of have finally được thể 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), Đã measuring the Sun's output since February 1980. Although a malfunction in the satellite's control system limited its observation for vài years, the satellite was Repaired in orbit by astronauts from the space shuttle in 1984. Max's observations indicate rằng 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 coal 0:05 percent of the Sun's mean energy output and lasting from days to a few What vài weeks. Scientists believe những fluctuations coincide with the appearance and disappearance of large groups of sunspots on the Sun's disk. Relatively are sunspots on the Sun's dark surface vùng have strong magnetic fields mà and a cooler temperature about 2,000 degrees Fahrenheit the rest of the Sun coal'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 the Earth's surface larger coal. Long-term variations in the solar constant are more Difficult to quyết. Although Solar Max's data have indicated a slow and steady decline in the Sun's output, some have thought rằng scientists of satellite's aging detectors less sensitive to might have over the years trở, thì falsely ngụ a drop in the solar constant. Possibility This was dismissed, Tuy nhiên, Solar Max's observations by Comparing with data from a similar instrument on NASA's Nimbus 7 operating weather satellite since 1978.