The longest-serving solar observatory in space has turned 25 and is still making significant contributions to solar research. Its old age has become an important merit.
25 years ago, the space probe SOHO (Solar and Heliospheric Observatory), a joint project of ESA and NASA, was launched. Since then, it has been orbiting around our star synchronously with Earth and, thanks to its uniquely unobstructed and multifold view, has shaped our current understanding of the Sun. Despite the increasing competition from more modern space observatories and despite a few technical aches and pains, SOHO's continuous data stream…