Warming Rays
As winter plays out here in the northern hemisphere, the days are getting longer, and the Sun is climbing a little higher in the sky. That combination means that a little more of the Sun's energy is reaching our part of the globe, so for many of us the days are getting warmer.
The solar energy that we receive begins its journey deep inside the Sun. It travels through surrounding layers of hot gas before it's finally released into space, where it crosses the 93-million-mile gulf to Earth.
The Sun produces energy in its core by combining the nuclei of hydrogen atoms to form helium. This process converts almost one percent of the hydrogen's mass into energy.
The energy eventually works its way out of the core, where it travels through fairly dense layers of gas through the process of radiation.
Close to the surface, the gas is less densely packed, so the energy finds a new way to travel. It heats up pockets of gas, which rise to the surface like the bubbles in a pot of boiling water. But the Sun's bubbles are bigger than Texas. In fact, Texas astronomers are using a new technique to study these bubbles during the Sun's 11-year magnetic cycle. More about that tomorrow.
As the bubbles reach the surface, they radiate their energy into space. The bubbles then cool and sink back into the Sun, where their gas is once again heated and lifted to the surface, allowing the Sun to shine toward Earth -- and the rest of the universe, too.
Script by Damond Benningfield, Copyright 2004
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
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