How a Coronal Mass Ejection Cme Affects Earth

The recent advancements in NASA solar observation satellites have greatly improved mankind’s ability to find out more about what happens when Coronal Mass Ejections (CME) occur on the sun. In 2009, twin satellites were able, for the first time, to show the speed, mass, structure and trajectory of a CME, while presenting a three-dimensional image of the event.

Not all CME come anywhere near the Earth or impact the planet, so “Geo-effectiveness” is a term that is used to describe the effects that happen when a CME heads toward Earth. There are two types of CME, the “Halo” CME and regular CME. “Halo” CME are aimed either directly at the Earth or directly away from the Earth and they cause a halo to form around the Sun. Halo CME are the ones that scientists are interested in when looking for an effect on the planet. The regular CME direct the plasma at angles that will lead the mass away from Earth.

Twin Solar Terrestrial Relations Observatory, or STEREO, satellites were launched in 2006. One is on a path that goes ahead of the Earth and the other Follows the Earth, collecting data and taking simultaneous pictures that allow a three dimensional image. 

Before, observers had to wait for hours or days to pass before the mass reached the Earth and data could be collected.

The effects include:

Billions of tons of plasma that travels through space at thousands of miles and up to about a million miles an hour per hour. 

Two different time scales: One time scale follows a rapid transit of the CME from the Sun to the Earth. The second time scale involves the longer lasting reactions that occur once the CME hits the Earth and sets other forces into motion.

A magnetic field that moves with the corona and creates a disturbance in the form of a shock wave, or “space tsunami”.

High energy solar cosmic rays that form when particles surrounding the corona are accelerated by the shock wave.

Disruptive space weather in the Earth’s magnetosphere and upper atmosphere that is caused by the high energy solar cosmic wave process. According to, the latest large storm on January 22, 2012 could be measured as actually compressing the magnetic field and shifting lines of magnetic force in ways that induced strong ground current. This created magnificent auroras in Norway, including this popular image.

The aurora borealis (Northern) and aurora australis (Southern) form when the magnetosphere is essentially turned into an electric generator that sends current to ground.

Electrical currents could be started in power lines, oil/gas pipelines, and other long metal structures.

When electrical charges build up in the metal structures of satellites, high energy electronic equipment can be damaged. This is especially important for telecommunications satellites, and advance warning helps the satellite operators.

The CME may trigger actions by satellite operators and power grid managers to cut off high voltage satellite operations or to shut down parts of earthbound power grids.

There can be various impacts on society, the planet’s habitability, electronic technology and systems, space based apparatus and space exploration, safety and productivity. Any activity that is satellite dependent is at risk of being taken offline, so it is a great advancement to have more data that will lead to earlier warnings.

Science Daily reports about the STEREO system and CME. 

Solar Physics from the University of Montana has an informative basic question and answer page.