Sun in the Solar System

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Astronomers did not center the Sun in the Solar System until Nicolaus Copernicus made an indisputable case for the heliocentric view in the 17th century. Until then, astronomers had assumed that the Earth was the central figure and the Sun was orbiting it. His calculations of the Sun in the Solar System were refined and extrapolated by the likes of Galilei, Kepler, and Newton.

The heliocentric point of view is now the only accepted perception of the Solar System, but there are many people who do not fully understand the underlying energy mechanism and many other aspects of our star. Here are many interesting facts about the Sun and the interactions of the Sun in the Solar System.

• The Sun accounts for 99.86% if the mass in our Solar System.
• The sun is over 75% hydrogen; therefore, the majority of the Solar System is made of hydrogen.
• The heliopause is the point where the Sun’s influence fades. That is about 90 AU from the star.
• Judging by the temperatures of the Sun, you would think that it would be impossible to send spacecraft to explore it, but the Solar and Heliospheric Observatory(SOHO), launched in December, 1995, has been continuously observing the Sun since. A more recent mission, NASA’s STEREO spacecraft, was actually two spacecraft, launched in October 2006. These twin spacecraft were designed to watch the same activity on the Sun from different vantage points, and give a 3-D perspective of the Sun’s activity.
• The Sun converts energy through the proton-proton chain. Proton–Proton fusion can occur only if the temperature of the protons is high enough to overcome mutual electrostatic or Coulomb repulsion. With quantum mechanics it was discovered that tunneling of the wave functions of the protons through the repulsive barrier allows for fusion at a lower temperature than formerly thought.

There are too many facts about the interactions of the Sun in the Solar System to list them in a single book, not to mention one article. There is one last fact to leave you with, though. The Sun is going to destroy the Earth as part of its evolution. In a few billion years it will be gin to produce more heat and swell into a red giant. All liquid water on the surface will oil away and parts of the surface will become molten. Isn’t science cool?

Here are a few articles from Universe Today about the Sun. For example, this one about magnetic fountains on the Sun, or this cool video of the Sun from STEREO.

Here’s NASA’s Solar System Exploration Guide on the Sun, and a link to more information from NASA’s Jet Propulsion Laboratory.

We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Check them out here.

References:
NASA Science: Heliosphere
NASA SOHO
NASA Stereo Mission
Wikipedia