23:46We’ve Seen the Sun’s Inner Corona For the First Time... and It's Not What We Expected
The Sun's corona reaches 10 million degrees Celsius while the surface 1,500 km below it is far cooler, and the answer to that puzzle hides in the innermost band no instrument could ever watch. ESA's Proba-3, launched in December 2024, solves it by putting the occulting disc on a separate spacecraft and flying the pair 144 metres apart to millimetre precision, autonomously, creating artificial eclipses lasting up to five and a half hours per orbit. Alex McColgan rebuilds both the engineering, a handoff chain from star trackers to a laser that pins the gap to 1 mm, and the first science: the inner corona is far more turbulent than expected, with plasma structures moving at 14 to 520 km per second, three to four times faster than previously measured, which means existing solar wind acceleration models are significantly off. It also covers the month the coronagraph spacecraft went dark after a software glitch drained its battery over an unstaffed weekend, drifting 80 km from its partner before the occulter's camera found it.
