Space Weather

	What is a CME? Coronal mass ejections (CMEs) are violent discharges of electrically charged gas from the sun's corona. The largest explosions in the solar system, CMEs launch up to 10 billion tons of ionized gas into space at speeds of one to two million miles an hour. CMEs can cause magnetic storms by interacting with Earth's magnetic field, distorting its shape and accelerating electrically charged particles trapped within. As such, they can affect communication systems, power grids and astronauts in space.
	Solar Energetic Particles This animation shows a CME erupting off of the sun, the energetic particles racing ahead of the CME and how these particles react with Earth's magnetic field and Mars’ magnetic field.
	Polar Sees Aurora Arrival On Nov. 20, 2003, two weeks after the record-setting Halloween solar storms, the same spot on the sun hurled a CME into space resulting in massive aurora visible as far south as Florida. The Polar spacecraft was flying around the South Pole at this time and saw this aurora australis (also known as the Southern Lights).
	How Do Active Regions Form? Scientists know that the solar explosions, called flares, are driven by distorted magnetic fields that suddenly snap to a new, less energetic configuration. Areas of intense solar explosions are called active regions. By peering beneath the surface of one area of the sun, scientists found that such active regions are comprised of many small magnetic structures that rise quickly from deep within the sun. Other magnetic structures replenish these as they emerge, which makes the active region grow.