Space Weather

The Earth/Sun Connection

The "solar wind," a constant stream of energized ions and atoms (collectively known as plasma) released from the Sun, flows continually toward earth. Periodically this stream is disturbed by storms on the sun – particularly coronal mass ejections that can release huge magnetic coils, like enormous bubbles of energy, into the solar wind. These solar supersonic shock waves gather speed and size as they approach Earth.

Like a protective shield around the Earth, the magnetic field, or "magnetosphere" protects our upper atmosphere from the direct effects of the solar wind. When the solar wind carrying a solar shock wave crashes into the magnetosphere, oppositely charged poles in the coil and in the magnetosphere connect. These connections allow solar wind energy to pour into the magnetosphere – generating huge amounts of electricity, on the order of several terrawatts (trillions of watts) of power – more than the entire power consumption of the United States. This enormous increase of energized particles in the ionosphere are the electrical storms characteristic of "space weather."

The energetic particles that constitute these storms – electrons, ions (positively charged particles formed when electrons are stripped from atoms), or whole atoms with much higher energy than normal – are potentially dangerous. They can seriously harm the sensitive electronic components and solar cells of satellites and are a health hazard for astronauts working in space. Because these radiation storms are invisible to the human eye it is vital to develop systems to predict and detect these storms so that people and satellites can be protected as we plan for more manned missions and satellites in this area. Solar storms also play havoc with ground-based radio communications and electric power grids.

The Center for Space Physics (CSP) at Boston University is involved in a number of ongoing missions to study space weather. In addition to TERRIERS, researchers at CSP are working with the SOHO and CLUSTER missions.