Since 1996, SOHO, the SOlar and Heliospheric Observatory, has been continuously monitoring the sun, the heliosphere, and the solar wind particles that stream toward the Earth. Its mission is to achieve a better understanding of the structure and dynamics of the solar interior, to gain better insight into the physical processes that form and heat the Sun’s corona, and to investigate solar wind.

SOHO operates in a halo orbit around the point where the gravity of the Sun and the Earth neutralise each other.

The SOHO spacecraft was built in Europe by an Astrium-led team. Its instruments were provided by more than 500 European and American scientists. SOHO was launched on 2 December 1995 by an American Atlas II rocket. ESA has extended Soho’s mission until at least 2012, 14 years beyond its planned lifetime.