The Sun Makes More Than Light

Understanding Sunshine
What we see as sunshine is the visible light that reaches Earth and lights our day. But the Sun also gives off energy in invisible wavelengths of light, such as gamma rays, X-rays, ultraviolet, infrared, microwave, and radio.

Spacecraft that orbit Earth and the Sun provide dramatic, close-up images of the Sun in different wavelengths of light. Heliophysicists color code the images to make them easier to interpret: they use artificial color to visualize the Sun in different wavelengths.

The Sun and the Electromagnetic Spectrum
The electromagnetic spectrum is the entire range of electromagnetic radiation (light). As wavelength increases, frequency and energy decrease.

This image of the Sun is actually three images merged into one. Heliophysicists took images of the solar corona at three wavelengths within the invisible UV range. They assigned a color code (red, yellow, blue) to each image, revealing what solar features, like flares, look like at the different wavelengths.




Satellite images reveal gusts in the solar wind.
© AMNH
(click to enlarge)
Solar Wind and Radiation

Solar wind drags the Sun's magnetic field along with it. Earth is almost always protected from the solar wind by its own magnetic field and atmosphere.
© AMNH
(click to enlarge)
The solar wind is a constant flow of hot gas that blasts out from the Sun's corona at a million miles an hour. Fortunately, Earth's magnetic field and atmosphere almost always protect us: typically, only a trickle of solar wind gets through, sliding down to the North and South Poles and producing radiant displays of light called auroras. Earth's magnetic field also protects us from the constant flow of dangerous radiation emitted by the Sun. However, sometimes magnetic explosions on the Sun, called solar flares, create storms in the solar wind. Under rare conditions, they can disrupt radio, cell phones, and GPS, or even cause blackouts on Earth. The Sun, the Sun's magnetic field, and the solar wind together form a dynamic, interconnected system called the heliosphere, which extends across our Solar System to beyond the Kuiper Belt.
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