Observing The Sun

1. Observing The Sun By : NicollettePecipajkovski 7F

2. About Our Sun The sun is the centre of the solar system. The sun is actually a star, just like the millions of stars in our universe. It is a huge bright, glowing ball with a diameter of 1,392,000 kilometers, and it is the nearest star to Earth.

3. What our sun is made up of The sun is not solid or liquid, of but is it is made up of gases. It is made up of about 75% hydrogen, 25% helium and 1% of other elements such as, iron, carbon, lead and uranium. To produce energy, hydrogen atoms in the suns core, crash into one another and create helium atoms. The sun has three layers. The centre of the sun is called the core, and this is the hottest part of the sun reaching temperatures of 15.6 million degrees Celsius (28 million degrees Fahrenheit). The middle layer of the sun is called the radiative zone. In this layer, heat radiation caries energy very quickly from the core of the sun towards the surface. The outer layer of the sun is called the convection layer. Here, the energy from the sun moves more slowly and hot bubbles of gas move around taking heat from the middle of the sun towards the edge of the sun. What we see as the visible surface of the sun is called the photosphere. The photosphere is the innermost layer of the suns atmosphere . Covering the photosphere is the chromosphere. This is around 2500 kilometers (1150 miles) thick.

4. These are the layers of the sun…

5. Looking at the Sun If you just look at the sun with the naked eye, it looks smooth, round and all the same colour. However if you look at it closely through a telescope it looks grainy (like it’s made out of millions of bubbles), it varies in colour and you can see black spots on it. These black spots are called sunspots. They are different shapes and sizes and they look darker because they are cooler than the material that is around them. The sunspots are caused by change in the suns magnetic field. The sun and other planets behave as they have a magnet inside them, which affects the space around it. It has a force that pulls metals such as iron but doesn’t pull at metals like aluminum. The further you are from the magnet the weaker the pull.

6. < Sunspots on the Sun. The Sun in our Solar System. > < The Sun as we see it.

7. The affect the sun has on Earth Without the sun, the Earth would be dark, cold and no forms of life would exist. The sun gives out huge amounts of light and heat energy. On Earth we are lucky to have enough light and heat to allow us to grow plants or crops, harvest them and turn them into food. Plants could not grow without heat and light, and if there were no plants, both animal and human life could not be sustained. It would affect the entire food chain, for example, animals need plants to survive (for food and shelter), people get a large amount of their food source from both plants and animals and none of this would be possible if light and heat wasn’t obtained from the sun.

8. Without heat or light trees could not grow. Without plants and animals we could not have these foods and without these foods we could not survive. None of this would be possible if we didn’t get light and heat from the sun.

9. YOHKOH Yohkoh (“Sunbeam”), is a solar observatory satellite. It was designed with lots of special telescope and other scientific equipment to be sent into space to get information on the energetic phenomena taking place on the sun, specifically to gain more information on solar flares in x-ray and gamma-ray emissions. Yohkoh has four instruments that could detect energy emissions from the sun. • The Brag Crystal Spectrometer (BCS) • The Wide Band Spectrometer (WBS) • The Soft X-Ray Telescope (SXT) • The Hard X- Ray Telescope (HXT)

10. YOHKOH On August 31st 1991, Yohkoh was launched into space from Kagoshimi Space Center in Southern Japan and was controlled there. Yohkoh sent information back to the base and other control centers, so they could gain more knowledge and understanding about the sun.

11. SOHO Soho, the solar and heliospheric observatory is a project that was developed between ESA and NASA and was an International collaboration. Soho was specifically designed to carry twelve scientific instruments on board the spacecraft to record data. The instruments were provided by European and American scientists. Soho is made up of two parts. The lower part provides the power and holds control panels, and the top party holds all the scientific instruments. The main objective of Soho was to study the sun from its deep core to the outer corona and the solar wind. Soho was launched on December 2nd, 1995 and moves around the sun in step with the Earth. This means that Soho has an uninterrupted view of the sun at all times and is better able to provide an accurate and continuous account of the events that occur around the sun. The success of satellites has given scientists, and their world, great knowledge and understanding of our solar system and will continue to do so in the future.

12. Fun Sun Facts • Sunlight takes 8 minutes 20 seconds to reach us. • The sun is 400 times farther away from us than the moon. • The sun is thought to be the same age as Earth. (4.6 billion years old). • The temperature at the surface of the sun is about 5,500 degrees Celsius but the core is about 15 million degrees Celsius.

13. Bibliography • The sun and other stars – World Books • Will the sun ever burn out? (Earth, Sun, and Moon) – Rosalind Mist • Astronomy – Christopher De Pree, Ph.D., and Alan Axelrod, Ph.D. • The night sky – Steve Massey • Planets – David A. Aguilar • Solar System Observer’s Guide – Peter Grego

14. By : Nicollette Pecipajkovski 7F 2013