The sun-observing SOHO spacecraft celebrates two decades of space-based science.
After 20 years in space, the European Space Agency and NASA’s Solar and Heliospheric Observatory, or SOHO, is still going strong. Originally launched in 1995 to study the sun and its influence out to the very edges of the solar system, SOHO revolutionized this field of science, known as heliophysics. Twenty years ago, the field of heliophysics looked very different than it does today. Questions about the interior of the sun, the origin of the constant outflow of material from the sun known as the solar wind, and the mysterious heating of the solar atmosphere were still unanswered. Now, not only do we have a much better idea about what powers the sun, but our entire understanding of how the sun behaves has changed. Watch the video to learn more.