Proba‑3 Finds Solar Wind at 250‑500 km/s in Corona
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- Proba-3 has performed 57 artificial solar eclipses since July 2025, gathering over 250 hours of high‑resolution corona video—equivalent to ~5,000 Earth‑based eclipse campaigns.
- ASPIICS coronagraph on Proba‑3 can image the corona down to 70 000 km (one‑tenth solar radius), a proximity no other space‑based coronagraph achieves.
- Andrei Zhukov’s team measured slow‑solar‑wind plasma blobs moving at 250–500 km s⁻¹ in the inner corona, three to four times faster than the ~100 km s⁻¹ speeds predicted by prior models.
- Joe Zender notes that the observed wide range of speeds, accelerations, and directions underscores the non‑uniform, small‑scale magnetic structures driving slow solar wind.
- Scientists are invited to analyze the remaining Proba‑3 data to address open questions about solar‑wind acceleration, coronal mass ejections, and the coronal heating problem.
Why it matters: The new measurements push slow‑solar‑wind speeds from the expected ~100 km s⁻¹ up to 250‑500 km s⁻¹, giving theorists a concrete benchmark to test magnetic‑field and plasma‑acceleration models. This data‑driven revision promises tighter space‑weather forecasts for researchers studying solar‑storm origins and informs the ongoing quest to explain coronal mass ejections and the coronal heating problem.
