For the second day in a row, an active region on the sun has erupted with a coronal mass ejection (CME), blasting a beautifully dynamic magnetic bubble of energetic plasma in the direction of Earth. It is powering through interplanetary space at a breakneck speed of 1,360 kilometers per second (that’s over 3 million miles per hour!)
A NASA spacecraft — one of two solar satellites called the Solar-Terrestrial Relations Observatory (STEREO) that are orbiting the sun in opposite directions — watched the CME expand and get launched into interplanetary space from a perfect vantage point.
On June 13, AR1504 erupted, producing a M1 class flare that was accompanied by a CME. According to Spaceweather.com, that CME will hit Venus on June 15th, Earth on June 16th and Mars on June 19th. Today’s CME, launched from the same location, is predicted to also slam into the Earth’s magnetic field on June 16, potentially generating a geomagnetic storm.
If the conditions are just right, a CME’s magnetic field can compress and distort the magnetic field of our planet, called the magnetosphere. If the rotation of the CME’s magnetic field is aligned just right, it may become “geoeffective,” causing the CME’s field to connect with the Earth’s magnetic field.
Should this occur, a geomagnetic storm may result, causing the injection of energetic solar particles into the magnetosphere and a rapid release of stored energy. The result is often spectacular displays of aurorae at high latitudes and potentially some interference to modern technology. Communication interference may occur and, during extreme geomagnetic storms, airliners may be directed away from polar regions and electrical surges in national power grids may be detected.