The Sun - Research Paper Example

 The Sun A picture taken by NASA's Extreme ultraviolet Imaging Telescope (EIT) over the course of 6 days, starting June 27, 2005 (The Sun) Sun is the nearest star for us and hence we can study about sun more compared to other stars. Sun is one of the mysteries for the scientific world because of its aggressive nature which prevents any deep exploration possible. The image given below was acquired from NASA's Skylab space station on December 19, 1973 which shows one of the most spectacular solar flares ever recorded, propelled by magnetic forces, lifting off from the Sun. (Hamilton) Sun is believed to be situated at the centre of solar system. Different planets, heavenly bodies like asteroids, meteors and comets rotate around the sun in different orbits. Sun has the major share of mass of the solar system (more than 90%). Sun belongs to our nearest galaxy milky way which consists of billions of different stars of different sizes and activities. “The sun is made of about 75% hydrogen and 25% helium by mass, with tiny trace amounts of metals and other compounds.” (Sunspots-modern research p.2) Sun light requires around 8 minutes reaching our earth. The light and heat produced by the sun is responsible for the biological evolution on earth. Plants need light for the preparation of food with the help of photosynthesis process. The heat produced by sun is responsible for keeping the temperature balanced in our atmosphere which is essential for the sustainability of life on earth. Though many facts about sun have been revealed by science, it is believed that many things about sun are still unknown to scientific world. It is not easy to reach sun like we reach in other planets because of the huge heat developed by sun. This paper briefly explains the characteristics of sun, sunspots, solar winds, different parts of sun and the anticipated future of sun. Some Known Facts About Sun Sun Statistics Mass (kg) 1.989e+30 Mass (Earth = 1) 332,830 Equatorial radius (km) 695,000 Equatorial radius (Earth = 1) 108.97 Mean density (gm/cm^3) 1.410 Rotational period (days) 25-36* Escape velocity (km/sec) 618.02 Luminosity (ergs/sec) 3.827e33 Magnitude (Vo) -26.8 Mean surface temperature 6,000°C Age (billion years) 4.5 Principal chemistry Hydrogen Helium Oxygen Carbon Nitrogen Neon Iron Silicon Magnesium Sulfur All others 92.1% 7.8% 0.061% 0.030% 0.0084% 0.0076% 0.0037% 0.0031% 0.0024% 0.0015% 0.0015% (Hamilton). “One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths. The Sun's outer visible layer is called the photosphere and has a temperature of 6,000°C (11,000°F). (Hamilton). The mystery around sun’s nature, static or moving, has been created different theories. As per the early belief the planets were stationed while sun was rotating. The reason for this belief was the occurrence of sun at different parts of sky at different times of a day. Later this belief again modified. This time people believed that sun remains static while the rest of the planets rotate around it. The day and night has been explained based on this theory as the portion of earth coming face to face with sun will have day and the opposite side of earth will have night. Bu t as per the latest evidences it is believed that sun is also rotating along with other planets and heavenly bodies. But we may not feel it because of the huge size of sun compared to earth. “The Sun's period of rotation at the surface varies from approximately 25 days at the equator to 36 days at the poles. Deep down, below the convective zone, everything appears to rotate with a period of 27 days.” (Hamilton). Different Layers of Sun Sun’s interior is made up of different layers one over other. Sun can be divided into four different regions based on the heat developed and also the different materials involved. The inner portion is labelled as core of sun. (Hamilton) The portion above core is photosphere, chromospheres and corona respectively. Only the last three regions, photosphere, chromospheres and corona are visible to us. It is difficult to watch core or core activities because of the extreme heat generated at this region. Photosphere is the region we see when we look at sun using our naked eyes. The core of the sun is the hottest region having huge temperatures capable of causing nuclear reactions like nuclear fusion. Chromosphere is a transparent region just above photosphere. Corona begins at the top of the atmosphere which will be visible only at solar eclipse when the glare of the Sun itself (its photosphere) is blocked by the moon. (The atmosphere of the Sun - the Corona) The energy produced at the core travels millions of years between the layers before reaching earth’s atmosphere. Various heat transfer techniques such as radiation and convection takes place within the different layers of sun. “The solar atmosphere is so hot that the gas is primarily in a plasma state: electrons are no longer bound to atomic nuclei, and the gas is made up of charged particles mostly protons and electrons”. (The Solar Atmosphere) The electrons and protons will come out from the control of nuclear forces and will exist in free state because of the immense energy provided due to nuclear fusion taking place inside the core of sun. The electric field associated with these charged free nuclear particles will result in strong solar magnetic fields which will contribute to the solar wind. “The centre of the sun is very hot (about 15 million degrees Celsius) and the pressure is immense (about 100 billion times the air pressure here on Earth).Because of that, atoms come so close to each other that they fuse. (The centre of the Sun) Nuclear fusion is the process of combining two hydrogen nuclei to form a helium nucleus as a result of which huge amount of heat is liberated. Nuclear fusion can be considered as the soul or spirit of sun since in the absence of nuclear fusion no heat process or chemical actions will take place inside the sun. In other words sun will be a dead star in the absence of nuclear fusion. “Energy generated in the Sun's core takes a million years to reach its surface. Every second 700 million tons of hydrogen are converted into helium ashes. In the process 5 million tons of pure energy is released; therefore, as time goes on the Sun is becoming lighter.” (Hamilton). Solar winds “A constant stream of particles flies from the sun, with a temperature of about a million degrees. They fly with a velocity of about 450 kilometers per second. The origin of the solar wind lies in the Sun's corona. The solar wind blows gas and dust oozing out of a cometary nucleus backward, creating the characteristic `tails' of comets” (Between the Sun and Earth - Solar wind) Haley’s comet is the best example to study the effect of solar winds. “The Sun is now in the quietest phase of its 11-year activity cycle, the solar minimum - in fact, it has been unusually quiet this year - with over 200 days so far with no observed sunspots. The solar wind has also dropped to its lowest levels in 50 years.” (The Sun) Most of the sun activities are still unknown to scientists and this peculiar calm also an answerless problem to science till now. Sun Spots “Dark spots, some as large as 50,000 miles in diameter, move across the surface of the sun, contracting and expanding as they go. These strange and powerful phenomena are known as sunspots” (Sunspots- introduction, p.1) Sunspots are dark parts of sun which are comparatively cooler than its surrounding regions because of the strong magnetic field associated with it. Though people knew about sunspots even before Christ, it was well observed only after the invention of telescope by Galileo. The Future of Sun “The Sun appears to have been active for 4.6 billion years and has enough fuel to go on for another five billion years or so.” (Hamilton) At the end of this period sun will be more dangerous to earth than it is now. Since all the process of nuclear fusion which is responsible for the energy liberation will be ceased at this stage, sun will become a dark body called black hole which is believed to be the death stage of a star. The helium content of sun will become heavier elements at this stage and hence the mass of the sun will be increased. If the mass of a body increases, as per the gravitational law in Physics, its gravitational force will also be increased. (Remember the equation gravitational force F = ma where ‘m’ is the mass and ‘a’ is the acceleration due to gravity.) Because of this increased gravitational force the sun can capture all its nearing planets and heavenly bodies and the future of earth also in jeopardy at that time. At the end of its life, the Sun will start to fuse helium into heavier elements and begin to swell up, ultimately growing so large that it will swallow the Earth. (Hamilton) Conclusions Sun is a mystery for the scientific world and most probably it will remain as it is in future also. The majority of the mass in the solar system is associated with sun and most of the sun matter remains in the plasma stage. Sunspots are the coolest regions inside the sun. Sun is divided into four different parts based on the layers; core, photosphere, chromospheres and corona. It is undergoing an unusual calm and quiet period with less solar activities now which remains as a mystery to the scientists. The sun is exhausting day by day by giving out its energy in the form of heat and light and finally it may become a black hole which can even swallow our earth as a whole. Works Cited 1. Hamilton Calvin J., Sun, Retrieved on May 24, 2009 from http://www.solarviews.com/eng/sun.htm 2. The Centre Of the Sun, Retrieved on May 24, 2009 from http://www.michielb.nl/sun/home.htm 3. The Atmosphere Of The Sun - the Corona, Retrieved on May 24, 2009 from http://www.michielb.nl/sun/corona.htm 4. Between The Sun And Earth - Solar Wind, Retrieved on May 24, 2009 http://www.michielb.nl/sun/inter.htm 5. The Sun, Retrieved on May 24, 2009, http://www.boston.com/bigpicture/2008/10/the_sun.html 6. The Solar Atmosphere, Retrieved on May 24, 2009, http://www.windows.ucar.edu/tour/link=/sun/solar_atmosphere.html 7. Sunspots -introduction, Retrieved on May 24, 2009 from http://www.exploratorium.edu/sunspots/ 8. Sunspots-modern research , Retrieved on May 24, 2009 from http://www.exploratorium.edu/sunspots/research2.html Read More