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Aditya-L1 sheds light on why the Sun's corona is hotter than its surface

Tuesday, 16 June 2026· 5 min read·Source: India Today

Scientists using data from ISRO's Aditya-L1 solar mission — specifically its flagship Visible Emission Line Coronagraph (VELC) — have found strong evidence explaining how the Sun's outer atmosphere (corona) becomes hundreds of times hotter than its visible surface, a long-standing puzzle in solar physics, in findings reported around June 15-16, 2026. The Sun's surface (photosphere) is about 5,500 °C, while the corona reaches around two million degrees. The work, involving the Indian Institute of Astrophysics (IIA), helps unravel the 'coronal heating' mystery and improves understanding of solar activity that affects satellites and communications on Earth.

Key Facts & Details

8 points

1
ISRO's Aditya-L1 mission data shed light on the coronal heating puzzle.
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The key instrument was the Visible Emission Line Coronagraph (VELC).
3
The Sun's surface (~5,500 °C) is far cooler than its corona (~2 million °C).
4
The Indian Institute of Astrophysics (IIA) was involved in the study.
5
Understanding the corona helps predict solar activity affecting satellites and GPS.

Deep Dive

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Aditya-L1 is India's first dedicated solar mission, positioned at the Sun-Earth Lagrange Point 1 (L1).
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VELC is the largest and primary payload, designed to study the solar corona continuously.
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Coronal heating — why the corona is hotter than the surface — is a major open problem in astrophysics.

Exam Focus

Which ISRO mission's VELC instrument provided new evidence on the Sun's coronal heating mystery?

Exam Relevance & Angle

ISRO solar-science breakthroughs are high-value space GA, tested on the mission (Aditya-L1), its location (L1) and the instrument (VELC).

Target Exams

SBI POSBI ClerkIBPS POIBPS ClerkIBPS RRB OfficerIBPS RRB AssistantRBI Grade BRBI AssistantNABARD Grade ASSC CGLSSC CHSLSSC CPORRB NTPCLIC AAONIACL AOUPSC CSEState PCS

Background & Context

Aditya-L1 is India's first dedicated solar observatory, launched by ISRO aboard PSLV-C57 in September 2023, and placed in a halo orbit around the first Sun-Earth Lagrange Point (L1), about 1.5 million km from Earth, enabling continuous, unobstructed observation of the Sun. Its primary payload, the Visible Emission Line Coronagraph (VELC), studies the solar corona. The 'coronal heating problem' — why the corona (millions of degrees) is far hotter than the photosphere (thousands of degrees) — has long puzzled scientists. The Indian Institute of Astrophysics (IIA), Bengaluru, built VELC and leads much of this research.