The Closest Star- Our Sun

Click Here to Share Powered by Close window Read more about The Sun - How Big is the sun by nineplanets.org The Sun Minimize Toolbar Maximize Toolbar How big is the sun? This image illustrates how large the sun is compared to the earth and our solar system. Tools    Wiwi Title 94 Online Share

History of Our Sun Worshipped as a deity (god) by many cultures throughout history Called Helios by the Greeks Called Ra by the Egyptians Ra, the god of the Sun Helios, Greek god carrying the Sun to its position in the sky

Why is the Sun important? Supports most life on earth by providing warmth required for survival (exception: underwater hydrothermal vent ecosystems) Allows plants to grow via photosynthesis which in turn absorb carbon dioxide and create oxygen

How does the Sun produce light and heat? Deep in the sun's core, nuclear fusion reactions convert hydrogen to helium, which generates energy. During fusion, hydrogen atoms are fused together to create a helium and release a tremendous amount of energy

How does the Sun produce light and heat? Particles of light called photons carry the fusion energy through the sun's spherical shell, called the radiative zone, to the top layer of the solar interior, the convection zone. There, boiling motions of gases (like in a lava lamp) transfer the energy to the surface. This journey takes about 100,000 years.

Layers of the Sun Bottom layer of outer sun: photosphere Followed by the chromosphere Ending with the corona, “crown” of light from the Sun

Features of the Sun – Prominence Prominences are arcs of gas that are anchored in the photosphere layer of the Sun Prominences extend through the corona layer of the Sun

Features of the Sun – Sunspots Sunspots are small, dark spots seen on the surface of the Sun Sunspots are caused by strong magnetic fields on the Sun’s surface One sunspot has North magnetic polarity and one sunspot has South magnetic polarity. Caused by the Sun’s rotation

Features of the Sun – Sunspots Sunspots form over periods lasting from days to weeks, and can last for weeks or even months. The average number of spots that can be seen on the face of the Sun is not always the same, but goes up and down in a cycle. Historical records of sunspots show that this sunspot cycle has an average period of about eleven years. Every solar cycle, the number of sunspots, flares, and solar storms increases to a peak, which is known as the solar maximum. Then, after a few years of high activity, the Sun will ramp down to a few years of low activity, known as the solar minimum. This pattern is called the "sunspot cycle” or the "activity cycle".

Features of the Sun – Solar Wind Sun releases solar wind. The solar wind is a stream of energized, charged particles, primarily electrons and protons, flowing outward from the Sun, through the solar system at speeds as high as 900 km/s and at a temperature of 1 million degrees (Celsius)! It is made of plasma. Our magnetic field protects the Earth from the solar wind, and as the solar wind’s charged particles interact with our magnetic field, auroras are created.

Features of the Sun – Solar Flares A solar flare is defined as a sudden, rapid, and intense variation in brightness. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. Radiation from past solar flares has been responsible for disrupting satellites, stretching the visibility of the Aurora Borealis down to the tropics, causing electronics and cellular devices to fail, and even causing telegraph wires to burst into flames. Scientists predict the sun’s solar flares will reach their peak in 2012