The Solar Mission that Survived Disaster and Found 5,000 Comets

The solar mission that survived disaster and found 5,000 comets

For thirty years, SOHO has watched the Sun from a stable perch in space, revealing the inner workings of our star and surviving crises that nearly ended the mission. Its long-term observations uncovered a single global plasma conveyor belt inside the Sun, detailed how solar brightness subtly shifts over the solar cycle, and turned SOHO into an unexpected comet-hunting champion with more than 5,000 discoveries.

30 years of SOHO staring at the sun | Space photo of the day for Dec. 2, 2025

This year marks the 30th anniversary of NASA's and the European Space Agency's Solar and Heliospheric Observatory (SOHO) spacecraft being launched into orbit.

A Lost Spacecraft Came Back and Changed How We See the Sun

For thirty years, SOHO has delivered an unprecedented, nearly unbroken view of the Sun, surviving multiple near-catastrophic failures and becoming a cornerstone of modern solar science. Its long-term observations unraveled mysteries of the Sun’s internal plasma conveyor belt, revealed subtle variations in solar output, and helped make space-weather forecasting a formal national priority. Along the [...]

Sun-watcher SOHO celebrates thirty years

On 2 December 1995 the ESA/NASA Solar and Heliospheric Observatory (SOHO) blasted into space – on what was supposed to be a two-year mission. From its outpost 1.5 million km away from Earth in the direction of the Sun, SOHO enjoys uninterrupted views of our star. It has provided a nearly continuous record of our Sun’s activity for close to three 11-year-long solar cycles.