At what wavelengths do the sun and earth radiate most of their energy and what is the sun's maximum energy wavelength?
The Sun and Earth radiate energy at different wavelengths due to their different temperatures. The Sun, with a surface temperature of about 5,500 Kelvin (5,227 degrees Celsius or 9,281 degrees Fahrenheit), emits most of its energy in the form of visible light, with a peak wavelength of about 500 nanometers (nm). Visible light is made up of the colors that we can see, from red to violet, with intermediate colors like orange, yellow, green, and blue.
The Earth, with an average surface temperature of about 15 degrees Celsius (59 degrees Fahrenheit), emits most of its energy in the form of infrared radiation, with a peak wavelength of about 10 micrometers (μm). Infrared radiation is invisible to our eyes, but we can feel it as heat.
The Sun's maximum energy wavelength is about 500 nanometers (nm). This is the wavelength at which the Sun emits the most energy. The wavelength of electromagnetic radiation is inversely proportional to its energy, so shorter wavelengths have higher energy than longer wavelengths.
The Sun, with a surface temperature of about 5,500 Kelvin (5,227 degrees Celsius or 9,281 degrees Fahrenheit), emits most of its energy in the form of visible light, with a peak wavelength of about 500 nanometers (nm). Earth, with a temperature of only 288 K, emits 390 Wm-2 at a peak wavelength of 1.005e-5 m or 10.05 mm. The Sun and Earth emit radiation of different wavelengths. The Sun's peak radiation is in the visible range; the Earth's peak radiation is in the infra-red range. Because the Sun is much hotter than the Earth, it emits much more radiation energy than the Earth. Since the temperature of the Sun is about 5800 K [5728°C], the majority of the radiation energy it emits is in the form of visible radiation. Gamma rays, shown on the far right side, have the highest energies, the shortest wavelengths, and the highest frequencies. Radio waves have photons with low energies, microwave photons have a little more energy than radio waves, infrared photons have still more, then visible, ultraviolet, X-rays, and, the most energetic of all, gamma-rays. The sun's rays are strongest at the equator where the sun is most directly overhead and where UV rays must travel the shortest distance through the atmosphere. The Sun, with a temperature of approximately 6000 K, emits 7.36e11 Wm-2 at a peak wavelength of 4.8e-7 m or 0.48 mm. The sun, with a surface temperature of approximately 5,780 K, emits radiation with peak intensity at wavelength of approximately 0.5 μm, which is in the green range of the visible portion of the electromagnetic spectrum. For the sun with a photospheric temperature of about 5780 K, λmax ~ 0.500 μm or 500 nm, which is the color green? However, for Earth with a mid-tropospheric temperature of about 260 K, the peak wavelength is closer to 11 μm, well into the infrared.
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