|
|
|
|||||||||||||||||||||
| of the Solar System |
| The Sun is an ordinary G2 star, one out of over 100 billion stars in our galaxy The Milky Way. Diameter: 1,390,000 km. Mass: 1.989e30 kg Temperature: 5800 Kelvin,9980.33 Farenheit or 5526.85 Celsius (surface) 15,600,000 K, 15599726.85 Celsius, or 28079540.33 Farenheit (core) The Sun is by far the largest object in the solar system. It contains more than 99.8% of the total mass of the Solar System. The Sun is presently about 75% Hydrogen and 25% Helium by mass. This changes slowly over time as the Sun converts Hydrogen to Helium in its core. The Sun is compromised into 6 areas. The core ,the radiative Zone,Convection zone, photosphere,chromosphere,and the corona. Conditions at the Sun's core are extreme. The temperature is 15.6 million Kelvin and the pressure is 250 billion atmospheres . The core's gases are compressed to a density 150 times that of water. The Sun's energy output (3.86e33 ergs/second or 386 billion billion megawatts) is produced by nuclear fusion reactions. Each second about 700,000,000 tons of hydrogen are converted to about 695,000,000 tons of helium and 5,000,000 tons of energy in the form of gamma rays. As it travels out toward the surface, the energy is continuously absorbed and re-emitted at lower and lower temperatures so that by the time it reaches the surface, it is primarily visible light. For the last 20% of the way to the surface the energy is carried more by convection than by radiation. The surface of the Sun, called the photosphere. (phootos = [Greek] light; sphairos = [Greek] ball) The photosphere is the deepest layer of the Sun that we can observe directly. It reaches from the surface visible at the center of the solar disk to about 300 miles (500 km) above that. The radius of the Sun (from its center to the visible surface) is 432,000 miles (696,000 km). The temperature in the photosphere varies between about 6500 K at the bottom and 4000 K at the top (11,000 and 6700 degrees F, 6200 and 3700 degrees C) and a density which is between about 4000 and 200,000 times smaller than the density of air at sea level on Earth. Most of the photosphere is covered by granulation. Sunspots are "cool" regions, only 3800 K (they look dark only by comparison with the surrounding regions). Sunspots can be very large, as much as 50,000 km in diameter. Sunspots are caused by complicated and not very well understood interactions with the Sun's magnetic field. A small region known as the chromosphere (chrooma = [Greek] color; sphairos = [Greek] ball) lies above the photosphere. The chromosphere is a layer in the Sun that is roughly between about 250 miles (400 km) and 1300 miles (2100 km) above the solar surface. The temperature in the chromosphere varies between about 4000 K at the bottom (the so-called temperature minimum) and 8000 K at the top (6700 and 14,000 degrees F, 3700 and 7700 degrees C), so in this layer (and higher layers) it actually gets hotter if you go further away from the Sun. The density in the chromosphere is much, much smaller than the density of air at sea level on Earth. The highly rarefied region above the chromosphere, called the corona( corona=[Latin] from koroone = [Greek] crown). The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the surface (the photosphere). The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more, up to a few million K. The corona cannot be seen with the naked eye except during a total solar eclipse, or with the use of a coronagraph. The corona does not have an upper limit: you could say that the Earth moves through the solar corona, though the density of the material near the Earth is usually only a paltry few particles per cubic centimeter extends millions of kilometers into space but is visible only during eclipses . Temperatures in the corona are over 1,000,000 K. The Sun's magnetic field (he Magnetos lithos = [Greek] stone of Magnesia) is very strong and very complicated.The magnetic field is a force field that is linked to moving electrical charge and affects charged particles and certain metals by either attracting or repulsing them. Almost all solar material is affected by magnetic field. Magnetic field behaves as if it consists of closed magnetic field lines (such as might be observed when a magnet is held under a glass plate with iron filings on it). Magnetic field in the Sun appears to exist in only two forms: Either it is so weak that it is passively swept along by the material, or it is so strong that it hinders movement (e.g. convection) of the material. In the latter case the magnetic field exists in the form of flux tubes: isolated tube-like structures in which the magnetic field is strong, while it is weak or absent outside the tube. Most of the interesting features on the Sun are associated with magnetic field: sunspots, pores, plage, filaments, solar flares, and prominences.Solar astronomers measure the strength of magnetic field in gauss (G). The magnetic field of the Earth is at most 1 G strong. The magnetic field inside a sunspot at the visible surface (the photosphere) of the Sun can get up to 3000 G strong. You can see magnetic field in magnetograms such as that on the Narrow-Band Image page. You can read about variations in the solar magnetic field and the effects this may have on the Earth in the Polarity page. Its magnetosphere (also known as the heliosphere extends well beyond Pluto. In addition to heat and light, the Sun also emits a low density stream of charged particles (mostly electrons and protons) known as the solar wind which propagates throughout the solar system at about 450 km/sec. The solar wind and the much higher energy particles ejected by solar flares can have dramatic effects on the Earth ranging from power line surges to radio interference to the beautiful aurora borealis. We've learned that Earth's atmosphere is protected from the solar wind by our magnetosphere. Even so, some solar wind energy does enter our magnetosphere and atmosphere and can cause a small amount of our atmosphere to be launched into space. We need to understand this loss of our atmosphere in order to understand our planet's environmental stability over a long time period. Solar wind energy in our magnetosphere can also cause what are known as space plasma storms. These storms can cause communication and science satellites to fail. They can also cause damage to electric power systems on the surface of the Earth. A large space storm in 1989 made currents on the ground that caused a failure in the Hydro-Quebec electric power system. This prevented 6 million people in Canada and the US from having electricity for over 9 hours. The same storm caused the atmosphere to inflate and dragged the LDEF satellite to a lower orbit earlier than expected. Recent data from the spacecraft Ulysses show that the solar wind emanating from the polar regions flows at nearly double the rate, 750 kilometers per second, that it does at lower latitudes. The composition of the solar wind also appears to differ in the polar regions. And the Sun's magnetic field seems to be surprisingly uniform. Further study of the solar wind will be done by the recently launched Wind, ACE and SOHO spacecraft from the dynamically stable vantage point directly between the Earth and the Sun about 1.6 million km from Earth. The solar wind has large effects on the tails of comets and even has measurable effects on the trajectories of spacecraft. Spectacular loops and prominences are often visible on the Sun's limb The Sun's output is not entirely constant. Nor is the amount of sunspot activity. There was a period of very low sunspot activity in the latter half of the 17th century called the Maunder Minimum. It coincides with an abnormally cold period in northern Europe sometimes known as the Little Ice Age. Since the formation of the solar system the Sun's output has increased by about 40%. The Sun is about 4.5 billion years old. Since its birth it has used up about half of the hydrogen in its core. It will continue to radiate "peacefully" for another 5 billion years or so (although its luminosity will approximately double in that time). But eventually it will run out of hydrogen fuel. It will then be forced into radical changes which, though commonplace by stellar standards, will result in the total destruction of the Earth (and probably the creation of a planetary nebula). There are nine planets and a large number of smaller objects orbiting the Sun. |
| Myths and Legends Around the World |
| For centuries, humans have attempted to explain the Sun in the terms of their own understanding. Myths and Legends represent a cultures worldview and are an attempt to explain,understand,and come to terms with nature's phenomena. In these Myths and Legends the Sun can be a God, a Demon, a mischievous spirit, an omnipotent creator or a ruthless taker of life. Whatever role it plays, many cultures have recognized the significance of the Sun as the prime controller of all life on Earth. Classical Greek The Greek Helios Apollo Classical Rome The Roman Sol Mesopotamia Shamesh Gilgamesh and the Sun Ancient Egypt Horus Judeo-Christian Bershith.. In the beginning Joshua halts the Sun African Liza Australia The Sun and the Moon China The Ten Suns Inuit Malina Japan Amaterasu North American Why there is Day and Night Raven and the Sun The THree legged Rabbit One who walks over the sky The Fifth World Aztec Huitzilopochtli Incan Inti Norse Freyr |
 Sign Guestbook |
 View Guestbook |
 midnightfire@wildmail.com |
|
. |
| Visitors: 06124 |
| Home | ||||||||
| Ancient History | Ancient History | |||||||
| Astronomy | Astronomy | Grand Conjunction | Nebulae | |||||
| Solar system | Planets | The Sun | Mercury | Venus | Earth | Mars | Jupiter | |
| Friends | Friends Around the World | |||||||
| New Age | divination | divination | ||||||
| astronomy | DarkNebulae | |||||||
| Nebulae | Reflection Nebulae | Emmision Nebulae |