Indian solar mission's new findings throw light on enduring Sun mysteries — SkimNews
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- Prof R Ramesh of the Indian Institute of Astrophysics led the study, published in Astrophysical Journal Letters, which for the first time puts hard numbers on two competing mechanisms for heating the Sun's corona.
- Aditya-L1's Visible Emission Line Coronagraph (Velc) recorded a coronal mass ejection on 5 August 2024, and within roughly 10 hours the corona's tangled magnetic field lines snapped back into place and restored the lost energy.
- The study found magnetic field reconnection supplies about 93% of the corona's energy, while bubbling, boiling motions on the Sun's surface — long assumed to be a major driver — contribute only 7%.
- The Sun's corona reaches temperatures of roughly 2 million Celsius and can spike to 40 million C, while the visible surface sits at just 5,500C, a gap Ramesh says "defies the laws of physics."
- In quiet periods the Sun launches two to three coronal mass ejections a day, rising to 10 or more during the 11-year solar maximum — each eruption releases so much energy that without rapid replenishment Earth would face what Ramesh calls an "irreversible deep freeze."
- Coronal mass ejections can trigger geomagnetic storms on Earth capable of knocking out power grids and disrupting weather and communication satellites, making the reconnection mechanism a practical as well as theoretical concern.
Why it matters: The 93-to-7 split gives solar physicists their first quantitative benchmark for separating wave-driven heating from magnetic reconnection, a ratio future corona models will be judged against. It also reframes Earth-side risk: with up to 10+ CMEs a day during solar maximum and a 10-hour recovery window, overlapping geomagnetic disruptions to grids and satellites become a statistical question rather than a rare-event one.
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