20 Years of Staring at the Sun

On Dec. 2, 1995, the joint ESA/NASA mission SOHO roared into space on an Atlas/Centaur rocket. Four months later SOHO (the Solar and Heliospheric Observatory) fell into its new home, a "halo" orbit 1.5 million kilometers away from Earth in the direction of the Sun. Soon thereafter it began its mission: to observe the Sun with its multitude of detectors, helping us understand our nearest star. That was nominally a two-year mission. This week, 20 years later, SOHO is still chugging along, celebrat...