About Solar and Heliospheric Observatory (SOHO):
- It is a project of international collaboration between the European Space Agency (ESA) and the U.S. National Aeronautics and Space Administration (NASA). It was launched in December 1995, SOHO was designed to study the Sun.
- In order to provide continuous observations, it was maneuvered to orbit the first Lagrangian point (L1), a point some 1.5 million km (900,000 miles) from Earth toward the Sun where the gravitational attraction of Earth and the Sun, combine in such a way that a small body remains approximately at rest relative to both.
- It carries 12 scientific instruments to study the solar atmosphere, helioseismology and the solar wind.
- Though its mission was scheduled to run until only 1998, it has continued collecting data, adding to scientists' understanding of our closest star, and making many new discoveries, including thousands of comets. It is the longest-lived Sun-watching satellite to date.
