Our Sun is the nearest star to us. It provides heat and light and occasionally spectacular displays, when the moon creates a solar eclipse. When we see the Sun during the day, we are seeing the light being emitted by the photosphere, radiating at a temperature of about 5800 K, but the corona just above that surface is at a temperature of 1-2 million degrees. Why this is so is not known. The sun is a huge ball of very hot plasma (ionized gas and magnetic field) that is constantly churning. In the solar interior, nuclear fusion reactions convert two hydrogen atoms into a helium atom, then into carbon, iron and other elements (and their isotopes), releasing tremendous amounts of energy. The ionized particles moving around, create magnetic fields, which erupt through the surface creating active regions, sunspots and prominences. The number of sunspots on the sun has been counted at least as far back as the invention of the telescope in about 1609, when Galileo recorded an image of the sun and counted the sunspots. The magnetic fields interact, causing flares, which are large releases of energy in the form of electromagnetic (EM) radiation, from the radio, infra-red up to gamma ray energies, and also energetic particles, both of which can impact the earth’s atmosphere. It takes about 8 minutes for the EM radiation to hit earth and at least 20 minutes for the energetic particles, which travel up to 1/3 of the speed of light. Sometimes the magnetic field interactions cause the expulsion of the coronal mass ejection (CME), a massive (1015 gm) ejection from the Sun of plasma that can travel sometimes supersonically, creating a shock wave ahead of it. It can take 1-3 days for the CME to travel the distance to earth, and, if it is directed at earth, can cause a geomagnetic storm which then can cause problems in electronic communications and our power stations. The famous Carrington event was a white light flare, seen by an amateur astronomer, Lord Richard Carrington, which disrupted the telegraph system in the United States, when it caused many telegraph wires to burn up and even telegraph keys to spark. The copper cores in power station transformers are known to melt during such storms and satellite malfunctions are also attributed to the storms. The signals from the Global Positioning System become distorted while traveling through the ionosphere disturbed by the geomagnetic storm. My own research has been characterizing the CME phenomena from the original discovery in 1971.