Gannon’s Storm discovery

Why in News?

• Aditya-L1, India’s first solar observatory, along with six U.S. satellites, has decoded why the May 2024 solar storm behaved abnormally.
• The storm, also called Gannon’s Storm, showed unexpectedly high geomagnetic impact on Earth.
• ISRO confirmed for the first time ever:
  • Magnetic reconnection occurred inside a Coronal Mass Ejection (CME).
  • The reconnection region spanned ~1.3 million km (~100× Earth’s size).
• Discovery made using joint data from:
  • NASA missions: Wind, ACE, THEMIS-C, STEREO-A, MMS
  • DSCOVR (NASA–NOAA joint mission)

Relevance

GS Paper III – Science & Technology

• India’s first solar observatory Aditya-L1.
• Breakthrough in heliophysics: internal magnetic reconnection in CME.
• Multi-satellite scientific collaboration (NASA–ISRO data fusion).

GS Paper III – Disaster Management

• Space weather as a non-conventional disaster risk.
• Threat to:
  • Power grids
  • GPS & NavIC
  • Telecom & aviation

Basics First: What Is a Solar Storm?

• A solar storm is a disturbance caused by:
  • Solar flares
  • Coronal Mass Ejections (CMEs)
• CMEs:
  • Giant clouds of superheated plasma + magnetic fields
  • Travel at 500–3,000 km/s
• When CMEs hit Earth:
  • Disturb magnetosphere
  • Cause:
    • Satellite damage
    • GPS errors
    • Radio blackouts
    • Power grid failures
    • Intense auroras

What Is a Coronal Mass Ejection (CME)?

• Massive magnetic “bubble” ejected from the Sun
• Contains:
  • Charged particles
  • Twisted magnetic field lines (flux ropes)
• Normally:
  • A single CME interacts with Earth’s magnetic field
  • Severity depends on magnetic orientation (southward = dangerous)

What Was Unusual in the May 2024 Storm?

1. Collision of Two CMEs in Space

• Instead of one CME:
  • Two CMEs collided mid-space
• Result:
  • Intense compression of magnetic fields
  • Triggered violent internal magnetic reconnection

2. Magnetic Reconnection Inside the CME (First-Ever Direct Evidence)

• Magnetic reconnection:
  • Process where:
    • Twisted magnetic field lines snap
    • Rejoin in new configurations
    • Release enormous energy
• Earlier belief:
  • Reconnection mainly occurs:
    • On the Sun
    • Near Earth’s magnetosphere
• New discovery:
  • It occurred inside the CME itself during transit

3. Scale of the Reconnection

• Size of reconnection zone:
  • ~1.3 million km
  • ~100 times the diameter of Earth
• Scientific significance:
  • Largest reconnection region ever observed inside a CME

Why Did This Make the Storm More Dangerous?

• CME collision caused:
  • Sudden reversal of magnetic fields
• Effects:
  • Stronger coupling with Earth’s magnetosphere
  • Higher:
    • Geomagnetic storm intensity
    • Ionospheric disturbances
    • Satellite drag
    • Power grid stress

Role of Aditya-L1 (India’s Strategic Edge)

• Payloads used:
  • Magnetometers
  • Plasma analysers
  • Solar wind detectors
• Contribution:
  • Provided precise 3D magnetic field mapping
  • Enabled localisation of the reconnection zone
• This marks India’s:
  • Entry into hard-core space weather physics
  • Leadership in real-time solar monitoring

Strategic Importance for India

• Protects:
  • NavIC
  • Defence satellites
  • Power grids
  • Telecom & internet
• Reduces dependence on:
  • U.S. and EU space weather alerts
• Supports:
  • Human spaceflight (Gaganyaan)
  • Lunar and interplanetary missions

Global Scientific Significance

• Improves:
  • Prediction models of CME evolution
  • Early warning systems for:
    • Aviation
    • Military communication
    • Stock exchanges
• Validates:
  • Multi-satellite cooperative heliophysics

Link with Global Space Weather Preparedness

• Major past disruptions:
  • Carrington Event (1859) – Telegraph systems failed
  • Quebec blackout (1989) – 9-hour grid collapse
• May 2024 storm confirms:
  • Modern digital civilisation is highly vulnerable to solar extremes

Conclusion

• The Aditya-L1–led discovery of internal magnetic reconnection during the May 2024 CME collision marks a paradigm shift in heliophysics.
• It establishes that:
  • CMEs are not magnetically stable objects
  • Their internal dynamics can amplify storm intensity mid-journey
• For India, this transforms Aditya-L1 from:
  • A scientific mission → a strategic national security asset

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