Kodaikanal Solar Observatory (KSO)

Kodaikanal Solar Observatory (KSO): The Department of Posts has released a special commemorative postage stamp to mark the 125th anniversary of the Kodaikanal  Solar Observatory (KSO).

• About KSO: One of India’s oldest and most prestigious scientific institutions dedicated to solar research.

o Situated on the southern tip of the Palani Hills in Kodaikanal, Tamil Nadu.

o Established: In 1899, by the Indian Institute of Astrophysics.

o Set up to study the link between solar activity and the Indian monsoon.

o Triggered by the Great Drought of 1875–1877, which caused massive famine and deaths across India and other countries.

o The Famine Commission suggested creating a solar observatory for systematic solar monitoring.

o Site Selection: Kodaikanal was chosen for its clear skies, low humidity, and minimal fog—ideal for solar observations.

o Scientific Contribution: In January 1909, the Evershed Effect (radial gas flow in sunspot penumbrae) was discovered here—an important solar physics breakthrough.