Astronomers Find the Source of Solar Wind

The solar wind originates from the Sun of course, everybody knows that, but not many can explain how solar wind is actually generated, at least not in an accurate manner. Yesterday, a team of researchers from the University College London's Mullard Space Science Laboratory, led by professor Loise Harra, presented their new findings related to the solar wind at the Royal Astronomical Society's National Astronomy Meeting, Belfast.

The solar wind is represented by a stream of electrically charged particles, originating from the Sun and flowing through the whole solar system towards the outer regions. Once released from the Sun, they can reach speeds exceeding 200 kilometers per second, meaning that they can travel the whole distance of 150 million kilometers to Earth in only 10 days.

Usually, mild solar winds are harmless to us and to the Earth in general, thanks to the powerful magnetic field protecting us, but strong solar storms can generate violent solar winds that may create powerful auroras and may even interfere with the correct functioning of satellites and electric power grids on the surface of the planet.

During observations with JAXA's Hinode Observatory in the middle of 2006, professor Harra revealed that hot plasma, shaped by the powerful magnetic field of the Sun, create extremely bright regions on the surface of the Sun. Eventually, these bright structures will be ejected into space at very high speeds. Regions on the solar surface as far away as 500,000 kilometers may be connected with each other through a powerful magnetic field line, which, when interacting with another magnetic field, snaps and releases massive quantities of matter into interstellar space in the form of solar wind.

"It is fantastic to finally be able to pinpoint the source of the solar wind - it has been debated for many years and now we have the final piece of the jigsaw. In the future we want to be able to work out how the wind is transported through the solar system," said professor Harra.