The Changing Faces of Our
Sun
The sun ... our celestial friend. It gives us beautiful sunrises and sunsets, lending us a warm solar glow, and cheering our spirits with it's visual glory.
Yet, something is going on with our solar star and system. Is the sun acting up, or is this just normal cyclic changes? What are these changes? What does it mean? Are we in store for earth changes, on a bigger scale? This page will explore these questions and more.
The Sun contains 99.86% of the mass of the entire solar system. It is held together by gravitational attraction, producing immense pressure and temperatures at its core, around 16 million degrees Kelvin, which is sufficient to sustain thermonuclear fusion reactions. The released energy prevents the collapse of the Sun and keeps it in gaseous form. In addition to the energy-producing solar core, the interior has two distinct regions: a radiative zone and a convective zone. Both the density and the temperature decrease going outward from the core towards the surface through these zones. Because the Sun is gaseous, it rotates faster at the equator (26.8 days) than at the poles (as long as 35 days). The Sun's "surface," known as the photosphere, is just the visible 500-km thick layer from which most of the Sun's radiation and light finally escape, and is the place where sunspots are found. Above the photosphere lies the chromosphere that may be seen briefly during total solar eclipses as a reddish rim, caused by hot hydrogen atoms, around the Sun. Temperatures steadily increase above the Sun's surface up to 50,000 degrees Kelvin, while density drops to 100,000 times less than in the photosphere. Above the chromosphere lies the corona or "crown," extending outward from the Sun in the form of the "solar wind" to the edge of the solar system. The corona is extremely hot - millions of degrees Kelvin. The process that heats the corona is very mysterious and not very well understood. Recent studies seem to link the Sun's magnetosphere and convection with the temperature of the corona.
The Sun: a Pictorial Introduction
The Sun Earth Connection
Coronal Mass Ejections
Stanford Solar Center
Solar Art
Space Environment Center
Geologic Hazards Team
Science
ArtWork by Hua Nian. Watercolor & pastel.
Thank you for your interest. This is going be full of interesting science links, and information....stay tuned. Thanks for your patience.
;-)
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